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Building a Backpacker “Scout” Rifle
by Roy Seifert


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Disclaimer:  This article is for entertainment only and is not to be used in lieu of a qualified gunsmith.  Please defer all firearms work to a qualified gunsmith.  Any loads mentioned in this article are my loads for my guns and have been carefully worked up using established guidelines and special tools.  The author assumes no responsibility or liability for use of these loads, or use or misuse of this article.  Please note that I am not a professional gunsmith, just a shooting enthusiast and hobbyist, as well as a tinkerer.  This article explains work that I performed to my guns without the assistance of a qualified gunsmith.  Some procedures described in this article require special tools and cannot/should not be performed without them.

Warning:  Disassembling and tinkering with your firearm may void the warranty.  I claim no responsibility for use or misuse of this article.  Again, this article is for entertainment purposes only!

Tools and firearms are the trademark/service mark or registered trademark of their respective manufacturers.  All tools were purchased from Brownells unless otherwise indicated.

Introduction
Col. Jeff Cooper developed the scout rifled concept.  His definition of a scout rifle was a bolt-action with a crisp 3-pound trigger chambered for the .308 Win. cartridge.  It should weigh between about 6.5 and 7.5 pounds, with an overall length of some 39.5 inches.  It would feed from a detachable-box magazine and have ghost-ring iron sights as backup or reserve sights.  Probably the most unusual feature of Cooper's design was the forward-mounted, low-powered scope.  Although he said this was not mandatory, it would preserve the shooter's peripheral vision, keep the ejection port open to allow the use of stripper clips to reload the rifle, and eliminate any chance of the scope striking one's brow during recoil.

To Cooper, the Scout was to be a general-purpose rifle for hunting and personal defense.  He didn’t care for the .223 Rem. cartridge, nor did he think the Scout Rifle needed more power than the .308 Win.  His idea was a short, compact rifle that could successfully deal with targets up to about 200 pounds at whatever range the shooter could keep his shots in an 8-inch circle, i.e. 2 minute-of-angle (MOA) which is 2-inches at 100 yards, 4-inches at 200 yards, or 8-inches at 400 yards.

Cooper felt a semi-auto rifle would work if the action were simple and it met the weight requirement.  I’m guessing that he never considered a lever-action rifle because it didn’t take a box magazine, and the lever would hit the ground when cycling in the prone position.  The tubular magazine of a lever gun has a limited capacity, and can’t take spitzer bullets because of the danger of setting off a round in the magazine due to recoil.  Hornady manufactures their LEVERevolution® cartridges using their FTX® bullets.  This Flexible Tip eXpanding bullet has a better ballistic coefficient than a typical .30-30 round nose bullet, which makes it more accurate, and the soft tip makes it safe to load in a tubular magazine.

However, the lever-action is faster than a bolt action, and although limited in capacity, the magazine can easily be topped up.  Some of the newer lever-action rifles manufactured by Henry can only be loaded from the front of the magazine tube like a .22 which makes them more difficult, but not impossible to top up.

Marlin 336 .30-30

 

Being a big fan of lever-action rifles, I decided to build a backpacker scout rifle.  I found a used Marlin 336 on Gunbroker.com for a mere $300.  With shipping and my FFL dealer’s transfer fee the total came to $348, which I thought was a great price.  I’ve seen these rifles in pawn shops and in used rifle racks as low as $200. 

As soon as I had the rifle in my shop I took it apart to do an inspection.  The rifle came with quick-detach sling swivels and a leather “cobra” sling.  According to the table at the end of this article, this rifle was built in 1976 which makes it a pre-Remington “bicentennial” rifle.

Fit and finish of this rifle were excellent, except for a sliver of wood missing from the wrist of the butt stock where it met with the receiver.  Although this was disclosed by the seller, I plan to replace the butt stock with a synthetic butt stock.  The wood had some dings and scratches from normal wear, which was to be expected. 

The action was smooth; with the hammer down I could work the action with one finger.  Using my trigger pull gauge, 8.5 pounds of force were required to lever the action.  My extensively reworked 1894CB only requires 3.25 pounds of force to lever the action.  I realize the 336 has a heavier bolt, but I can certainly get that 8.5 pounds down.

The trigger had some creep and was rough, but broke at 5.5 pounds.  The bore was bright and clean with no signs of wear or corrosion.  The rifle was very dry, probably from sitting in a gun safe or cabinet, but overall the rifle appeared to have been well cared for with no signs of rust, but not used very much.  It also appeared to have never been worked on because all the parts still had bluing except where they rubbed together during normal use.

To my surprise, this rifle did not have the cross-bolt safety; that was not added until 1984.  To carry the rifle safely with a loaded round in the chamber I would have to carefully place the hammer into the half-cock position like other shooters have done for over 100 years.  Another interesting quirk about this rifle, the butt stock did not have the signature bullseye because someone removed it and installed a sling swivel stud with epoxy and/or plastic wood.

Build Plan
To build my backpacker scout I plan to perform the following:

·         Polish and tune the internals and perform a trigger job

·         Cut the barrel to 16.5-inches – 16-inches is the minimum legal length for a rifle barrel

·         Cut the magazine tube to match the cut barrel

·         Install a synthetic youth butt stock so it fits my shoulder better

·         Convert it into a takedown rifle like I did to my Rossi ’92 (refer to my article Building a Lever-Action Takedown Rifle). 

·         Add a scout rail to the barrel

·         Apply a camouflage pattern using spray paint

·         Add a scout scope or red dot sight to the rail

·         Add backup ghost sights to the receiver

I found a Marlin 336Y youth model on Gunbroker.com for $300 dollars, but I was afraid it was built by Remington and I didn’t want to spend time attempting to repair a poorly built rifle.  The youth model comes with a 16.5-inch barrel and a shorter butt stock, but I wanted to do the gunsmithing myself.

Polishing Tools
A word about polishing – I read many gunsmiths say to just polish and not remove any metal.  Polishing, by its very nature, removes metal.  In most cases, the goal of polishing is to remove burrs, high spots, and tooling marks, but not alter the shape of the part.  I used the following tools to perform the polishing work:

 

·         400 and 600-grit polishing sticks – available from Boride Engineered Abrasives.  They make a gunsmithing kit with coarse and fine, wide and narrow polishing sticks that I have used on many guns.  Oil is used to clean these polishing sticks.

 

·         Fine Arkansas stone – available from Brownells.   They make a 4-stone set #975-104-000 that comes in different shapes perfect for gunsmithing use.  Oil is used to clean these stones.

 

·         Ceramic Polishing Stones, Black Medium-Fine #080-721-604 White Extra Fine #080-721-601 – Available from Brownells used to polish the sear.  Water is used to clean a ceramic stick.

·         400 and 600 grit wet/dry sandpaper – Available at most hardware stores.  When placed on a flat surface, or wrapped around a dowel or flat stick I use this to polish large areas. 

Working on the Bolt

To begin slicking up the action I worked on the bolt first.  I ran a 220-grit polishing stick in the ejector groove to remove the milling marks.  I polished again with a 400-grit stick, then finished polishing the groove with 600-grit wet/dry sand paper wrapped around a flat stick.

 

I then polished the channel in the bolt where the tip of the lever rides with a 400-grit stick.  I polished the inside edges, and removed the burrs from the outside edges.

 

Many gunsmiths or tinkerers reduce the hammer face so the bolt doesn’t have to exert so much pressure on the hammer spring.  I use a slightly different method as described in Accurizing the Factory Rifle by M. L. McPherson.  I used a blue marker to color the underside of the bolt where it rides on the hammer.  I cycled the action a few times so I could see the wear mark.  This highlighted the camming surface that cocks the hammer when the bolt is levered to the rear.

 

I used my milling machine and milled off most of the camming surface leaving about 1/8”.  This reduced the amount of surface area riding on the hammer, which reduced the amount of pressure riding on the bolt.

I used a Cratex tip and my Dremel tool to polish the cam so it would ride smoothly over the hammer.  This surface was rough from the factory and needing some smoothing.

Finally, I used a 400-grit polishing stick to polish off the high spots from the inside of the locking bolt channel.  I was careful not to change the dimensions of this channel because I still wanted the locking bolt to fit properly.  In the photo above you can see where I have begun to remove some of the high spots.

Polishing the Firing Pin
I disassembled the bolt to work on the firing pin.  The bolt comes apart with two roll pins.  To get to the front roll pin I had to remove the extractor by prying it from the bolt.

 

The top of the lever rubs against the firing pin in two places; the front cutout as indicated by the worn bluing in the above photo, and the front edge of the notch as indicated by the arrow.  I polished both areas with a 400-grit polishing stick.

Sticky Bolt
After reassembling the bolt, I discovered the bolt was dragging in the receiver.  I found that in the process of disassembling the bolt I had bent one of the legs of the extractor so it wouldn’t sit completely down in the extractor cutout.  It was raised just enough to drag on the inside of the receiver. 

I removed the extractor and bent the two legs closer together.  This applied more pressure on the bolt, which allowed the extractor to sit completely down into the cutout in the bolt.  The bolt now slides freely in the receiver.

Working on the Ejector

 

I polished the sides of the ejector by rubbing them on 600-grit wet/dry sand paper placed on a flat surface.  I used a Cratex tip and my Dremel tool to polish the tip that rides in the groove in the bolt.  After polishing I cold-blued the ejector with Brownells Oxpho-Blue Creme #082-124-004.

I bent the ejector spring just a bit as indicated by the dashed line in the above photo.  This was so the ejector wouldn’t put too much pressure on the bolt.  After bending the spring, the bolt rode more smoothly in the receiver, and the ejector still ejected cases properly.

Working on the Trigger Safety Block Spring

 

I removed the trigger guard plate from the bottom of the receiver.  The trigger safety block spring performs two functions; it activates the trigger safety block (bottom leg in the above photo), and is the trigger return spring (top leg in the above photo).  This spring is very stiff by design, but can be lightened.  I used a dental pick to carefully bend up each leg so there wasn’t so much tension on the trigger or trigger safety block.  Both still functioned as designed, but the trigger pull was much lighter.  This was a trial and error process; each leg of the spring must still provide tension.

Working on the Sear
Caution, this work should not be performed without the proper tools to prevent rounding the sear which could cause the rifle to become unsafe.

Ok, with the necessary disclaimer out of the way let’s talk about trigger pull.  There are primarily three things that affect the weight of trigger pull; trigger return spring tension, hammer spring tension, and the sear engagement angle with the hammer.  The trigger return spring tension can be reduced by replacing the spring, bending the spring, or cutting coils.  As mentioned before, I carefully bent the leg of the trigger safety block spring that acts as the trigger return spring to reduce spring tension.

The hammer spring, or mainspring, forces the hammer notch against the trigger sear.  The heavier the spring, the more pressure is placed on the sear, which requires more pressure on the trigger to release the sear.  A lighter hammer spring can lighten the trigger pull, but as you will see, I installed a factory hammer spring.  A perfectly smooth, flat sear with the proper angle can go a long way to reducing the amount of pressure necessary to release the sear.

I wanted to polish the sear to get it glass smooth and flat which would eliminate any gritty feel.  I also wanted to change the angle just a bit to lighten the trigger pull.  I disassembled the trigger guard plate assembly and removed the sear by drifting out the pin holding the trigger and sear in place. 

 

As mentioned before, the hammer and sear mating surfaces should be flat and square so the entire surfaces meet.  I’ve worked on some Marlin sears that were ground crooked so only one edge mated with the hammer.  They should also be in line with the center of the pivot point of the hammer as shown by the green line in the above diagram. 

 

Trigger pull can be increased or decreased by changing the angle of the sear.  Changing the angle in the direction of the green line increases trigger pull.  Changing the angle in the direction of the red line decreases trigger pull.  This must be done carefully; if the sear is cut too much in the direction of the red line the hammer can slip off the sear and cause an unsafe condition.

 

I already had the Power Custom Series I Stoning Fixture #743549 and purchased the Marlin 336 Adapter #917687; both came from MidwayUSA.com.  I installed the adapter onto the fixture, and installed the sear onto the adapter.  I marked the sear surface with a blue marker and adjusted the guide so my black, medium-fine ceramic stone was polishing the sear surface flat.

I adjusted the guide up 20 clicks to change the angle of the sear by 5-degrees to make the trigger pull lighter.  The adjustment screw is a 7/16-16 screw, which is 16 threads per inch (TPI).  The adjustment wheel has 4-clicks per turn.  One click is about 1/4-degree of change, one full turn of the wheel is about 1-degree of change, so 20-clicks is 5 full turns, which is about 5-degrees of angle. 

I used a 400-grit polishing stick to cut the new sear angle, then used the black medium-fine ceramic stone to polish the new sear surface.  I finished polishing with the white, extra-fine ceramic stone until the sear surface looked like a mirror. 

 

After changing the sear angle, I reversed the sear in the jig and ground a break away angle in the rear of the sear.  This causes less of the sear to contact the hammer further reducing trigger pull.

Working on the Finger Lever

Each side of the top of the finger lever had rough tooling marks and worn bluing where it was rubbing on the inside of the bolt and the carrier.  I polished both sides with a wide 400-grit polishing stick.  I didn’t remove all the tooling marks, but I polished just enough to remove any burrs and high spots.  I rounded the sharp edge shown by the blue arrow in the above photo which helps to prevent the rifle from jamming.  If left sharp, this edge can cut into the carrier, which can cause jams.

I used a Cratex bit to polish the end of the lever as shown by the red arrows in the above photo.  These areas ride against the inside of the bolt and firing pin.

 

The finger lever plunger keeps the lever in place when the action is closed.  The two angled surfaces were rough and had tooling marks.  I removed the pin that holds the plunger in the lever and polished the two angled surfaces with a 400-grit polishing stick until the tooling marks were completely removed.  I reinstalled the plunger with a Wolff reduced power finger lever plunger spring #33105.  Some folks cut coils off the spring instead of replacing it, but if the spring is too weak it won’t hold the lever closed.

Replacing the Hammer Spring

 

When I disassembled the rifle, I discovered a previous owner had replaced the factory spring with a Wolff reduced power hammer spring #32501.  I read an article on the Internet that stated reduced power hammer springs can cause erratic ignition, which can cause accuracy problems.  After performing all the polishing, I replaced the reduced power hammer spring with a factory spring.  The action was much smoother, and I could easily cycle the action with the rifle on my shoulder. 

Working on the Hammer

 

The hammer required a little bit of work to make it smoother, and to make the trigger pull crisper.  I used a Cratex bit and my Dremel tool to polish the face and top curve of the hammer as indicated by the red arrows in the photo above.  The full-cock notch (blue arrow) measured 0.030” which made the trigger pull long with some creep.  Using a 400-grit polishing stick, I reduced the depth of this notch to 0.018” which made the trigger pull nice and crisp with no creep, but still safe.  I was careful not to reduce the depth of the notch too much, otherwise the sear could contact the half-cock notch and break it when the hammer is released.  After working on the sear and hammer, the trigger pull was crisp with no drag and measured 2-pounds. 6-ounces.

Polishing the Locking Bolt

 

I didn’t do much polishing on the locking bolt since it already slid smoothly in the receiver.  Using a 400-grit polishing stick, I polished the sides to remove the high spots and burrs, and polished the front where it impacted the bolt.  I used a Cratex bit to polish the indentation where the rear firing pin rides.

Polishing the Carrier

 

I polished the front and top of the carrier where the cartridge cases ride, and the sides where the pivot screw hole is located with a 400-grit polishing stick (blue arrows).  I polished the concave area where the cartridges ride into the chamber, and the tip of the carrier rocker with a Cratex bit (red arrows).  Finally, I polished the sides of the carrier rocker by rubbing them on 600-grit wet/dry sand paper placed on a flat surface (green arrow).  I cleaned everything off with brake parts cleaner, lubricated the carrier rocker with grease, and reassembled the carrier.  I applied a small amount of grease on the flat sides around the pivot screw hole, and in the hole itself and reassembled the rifle.

Fabricating a Front Barrel-Band

 

One problem I immediately noticed with this rifle was that the magazine tube was pressing against the end of the barrel, which would probably have a negative effect on accuracy.  Minimizing the amount of contact with the barrel should provide some increase in accuracy.  I believe the reason Marlin did this was so the 6-40 barrel-band screw would fit through the notches in the barrel and magazine tube to hold the magazine tube in place.  To accomplish this the front barrel-band had to squeeze the magazine tube closer to the barrel, which caused it to touch the barrel.  This also put some tension on the magazine tube.

 

With the front barrel-band removed you can see that the magazine tube is straight and not touching the barrel.  The gap measured 0.090”.  The rear barrel-band screw doesn’t even touch the magazine tube, which will make it easy to move forward for disassembly once I convert the rifle into a takedown.

I decided to fabricate a new front barrel-band for two reasons; one because I plan to cut the barrel down to 16.5 inches so the original front-barrel band won’t fit because of the barrel taper.  I could ream the barrel-band, but it will sit back too far from the end of the muzzle for my purposes.  Reason two, the front sight will be an integral part of the new barrel-band.  I won’t have to drill and tap the barrel for the factory ramp, therefore, the new barrel-band can set closer to the muzzle.  This allows me to fabricate a shorter magazine tube plug, which saves some usable capacity in the magazine tube.  The new barrel-band won’t squeeze the magazine tube close to the barrel; the tube will be straight, which will eliminate any stress or flex making it easier to pull forward for disassembly, and it won’t touch the barrel.

 

I carefully measured the diameter of the barrel and the magazine, and measured the distance between the bottom of the barrel and top of the magazine tube at the location of the new barrel-band.  I increased the diameter of the magazine tube hole so the magazine tube wouldn’t bind; it must be able to move freely.  I fabricated the new front barrel-band out of 3/4” 6061-T6 aluminum.  Everything was the same as the barrel-band I fabricated for my Rossi ’92 except I milled a contour to the sides instead of leaving them straight.

 

I ordered a Williams 336 WGRS Fire Sight set #945296 from MidwayUSA.com.  I replace the red fiber-optic rod with a green one as I did on my Rossi ’92.  The photo above looks a little strange because I haven’t cut the barrel and magazine tube yet.

Cutting the Barrel and Magazine Tube

 

I chucked the barrel in my lathe and used a cutoff bit to cut the barrel down to 16 3/4“.  Because of the configuration of my lathe I couldn’t cut the barrel any shorter.

 

I then used a 1/2” 79-degree crowning cutter #080-586-500 with a .30-caliber pilot #080-686-308 I purchased from Brownells to put an 11-degree crown on the barrel.  I used plenty of oil to lubricate the pilot and cutter.  The above photo shows the end of the barrel, the pilot, and the crowning cutter.  The cutter is pulled away from the barrel to expose the pilot.

 

Finally, I used a brass muzzle lap #080-764-350 and 400-grit lapping compound to remove any burrs from the muzzle.  I put the lap into my variable speed drill, applied lapping compound to the end, and with the drill running at a slow speed, rotated the end of the lap in the muzzle maintaining the angle shown in the above photo.  This makes the lands and grooves nice and sharp.  I cold blued the exposed metal with Van’s Instant Gun Blue.  I heated the barrel with a hair drier and applied the cold blue until I got the deep blue/black color I wanted.

Cutting the Magazine Tube

 

I chucked the magazine tube in my lathe and cut off the front so it was 1/4” shorter than the shortened barrel.  I measured the location of the original hole for the magazine tube plug and milled the new hole in the shorter magazine tube.

 

Here is the shortened barrel and magazine tube.  I’m not worried about any scratches to the bluing because I plan to cover the rifle with a camouflage pattern.  The paint will cover any imperfections in the bluing.

Installing a Synthetic Youth Butt Stock
My arms are not very long so I have to either cut the buttstock or install a shorter one for a rifle to fit me comfortably.  I purchased a new Champion synthetic youth model stock set #78092 from ebay for a reasonable price.  This is also available from MidwayUSA #330364.  This youth model butt stock is 1 1/4” shorter than the factory butt stock and comes with a recoil pad installed.

This butt stock fit very tightly onto the receiver.  I used a Dremel tool with a narrow grinding stone to relieve each channel where the receiver tang and trigger guard plate set.  I kept the stone moving so I wouldn’t leave any hollows in the plastic.  When finished, the butt stock still fit snuggly onto the rifle, but it was easier to remove and install.  I drilled out the butt stock screw hole with a 17/64 drill bit so I could get the butt stock screw installed.

 

The shorter butt stock fits me better, and makes it much easier for me to lever the action.  I could not install the synthetic hand guard that came with the set because it is mostly hollow.  It needs to be solid to accept the adjusting screws from the takedown spacer plate, so I will keep the wooden hand guard.

Adding a Sling Swivel Stud to the Lower Band
The newer model 336 rifles have a sling swivel stud mounted to the lower barrel-band.  Many years ago, I purchased a package of 12 Uncle Mike’s® sling swivel studs #2516-0.  They come with a 10-32 x 1/8” threaded end.  Apparently Uncle Mike’s is no longer selling these, but a company called GrovTec manufactures a similar item available from MidwayUSA.com #190531.

 

I carefully marked the center bottom of the barrel-band and milled a 0.159” hole, then tapped the hole with a 10-32 tap.  I installed the stud with Loctite red for a permanent attachment, then filed off the end of the stud until it was flush with the inside of the band.  The band fit perfectly back onto the fore arm.

Fabricating the Magazine Tube Takedown Parts

 

I fabricated the takedown parts the same as I did for my Rossi ’92 based on the measurements I made for the 336.  I fabricated a new magazine tube plug out of 6061-T6 aluminum, and the takedown button out of 1/4“ steel round bar.  I milled a 3/16” semi-circle out of the bottom rear of the new front barrel-band and into the magazine tube, then milled a 1/4“ hole in the magazine tube plug.  I staked the end of the magazine tube so the follower wouldn’t fall out, and fabricated a longer magazine tube follower out of aluminum.  With the new magazine tube plug in place in the shortened magazine tube, and the new follower and shortened magazine spring, I could still fit 5 cartridges in the magazine tube, so I reduced the capacity of the tube by only one cartridge.

 

Since there is now nothing holding the magazine tube in place other than the takedown button, when pulled forward for takedown, the tube can come completely out of the rifle and get lost.  To prevent this from happening I installed a magazine tube sling swivel stud just below the front barrel-band.  This stud also gave me something to hold on to when moving the magazine tube forward.

To prevent the magazine tube from moving too far backwards when the rifle is disassembled, I installed a 6-40 filister head screw in the magazine tube and magazine tube plug in front of the new barrel-band.

Fitting an XS Lever Scout Mount

 

I found a used XS Lever Scout rail with all mounting hardware on ebay for $25.00 plus shipping.  MidwayUSA has them for $63.90, so I think I got a great price.  Because I’m building a takedown rifle, this mount cannot be attached to the receiver.

 

The XS Lever Scout rail mounts to the rear sight dovetail with a dovetail pillar.  The instructions state to sand or file the bottom of the dovetail until the pillar fits into the dovetail.  I placed the bottom on a piece of 600-grit wet/dry sand paper and briskly moved it back and forth.  I rotate the pillar so I wouldn’t be putting too much pressure on one side or end.  I tried for fit frequently, and sanded until I could install the pillar into the rear sight dovetail with finger pressure.  I installed the rail onto the barrel with the pillar screw and nut, and installed the rear screws into the receiver.

 

I removed the butt stock, magazine tube, fore end and front barrel-band from the rifle, then set it and leveled it in the machinist vise on my CNC mill.  I milled two holes to accept 6-48 filister-head screws in the locations indicated by the red arrows in the first figure.  The holes for the screw shanks were 0.112” x 0.325” and were 1/2” apart.  The rail measured 0.192” thick and I wanted the depth of the screw holes into the barrel 0.133”.  The holes for the filister heads were 0.212” wide by 0.115” deep.  I located the new mounting holes forward by 1/2” because the rear-most flat of the rail was over the chamber and I wanted thicker metal for the screw holes in the barrel.

 

After the holes were milled I tapped the holes in the barrel with a 6-48 bottom tap and drilled out the center hole in the XS rail with a #27 drill bit.  I cut the rail at the 4th groove from the rear with a hacksaw.  I used a hose clamp to guide the hacksaw blade.  I squared the end with a file and polished it with 400-grit wet/dry sand paper.

 

I installed the rail onto the barrel using two 6-48 x 3/16 filister-head screws from the Pachmayr Master Gunsmith Screw Kit I purchased from MidwayUSA.com #967567; everything fit perfectly

Removing the Barrel

 

I made a barrel vise bushing out of aluminum, installed the barrel vise and bushing onto the barrel with rosin, and installed the receiver wrench onto the receiver protected with tape.  The barrel came loose with a loud crack.

Milling the Front of the Receiver

 

I set the receiver between two oak blocks in my machinist vise and squared the front.  I used a 1/2” square-end bit to mill off the lip from the front of the receiver.  I removed 0.005” at a time so the bit wouldn’t chatter or move the receiver in the vise.  When I got close to the receiver face I finished by draw-filing with a bastard file until the lip was gone, then polished with 400-grit wet/dry sand paper wrapped around the file.  I cold-blued the exposed metal with Van’s Instant Gun Blue.

Milling a Step in the Barrel

 

I fabricated a mandrel 1.000” long by 0.415” wide out of 1/2” aluminum rod and used a centering bit to drill a V in the end for my live center.  I inserted the mandrel into the chamber and mounted and centered the barrel in my lathe.  I turned a step in the barrel that measured 0.815” wide x 0.490” long.  The spacer plate is 0.8135” for a press fit.

Fabricating a Spacer Plate
I carefully measured the barrel and magazine holes in the receiver, the space between them, and the distance from the top of the receiver.  I enlarged the barrel hole to 0.8135” and the magazine tube hole to 0.680”, but left the space between them the same.  The horizontal line extending from the center of the barrel hole represents a scribe line that will help me align the extractor notch in the barrel with the plate.

 

I traced around the receiver then scanned the outline into my computer.  I used CorelDraw 12 to create the drawing of the spacer plate, which I exported to BobCAD-CAM v20 to create the CAM code for my CNC mill.  I milled the plate out of 1/2” 6061-T6 aluminum stock.

Installing the Spacer Plate

 

I heated the aluminum spacer with a propane torch, and to my surprise, it dropped freely over the step in the barrel with no force required.  I made sure the alignment mark I scribed in the rear of the plate was in the center of the ejector notch in the barrel.  After the plate cooled it was nice and tight on the barrel.

Fitting the Spacer Plate

 

I faced off the rear of the spacer plate until it fit tightly and was properly aligned with the receiver.  I made shallow cuts 0.005” at a time and installed the receiver frequently until I got the proper fit.  The final cut was only 0.002” to achieve a tight fit.

 

I polished the outside edge of the plate by shoe-shining with 400-grit wet/dry sand paper until it blended with the receiver.

Cutting and Installing the Fore End

 

I measured from the fore end notch in the barrel to the front face of the spacer plate at exactly 8-inches.  I covered the rear of the fore end with masking tape so the wood wouldn’t splinter when cut, and marked the fore end 8” from the barrel band screw hole.  I cut the fore end to that mark. 

I installed the fore end onto the rifle and used a #21 drill bit to drill through the holes in the spacer plate into the fore end.  I opened the holes in the fore end with a #9 drill bit.  I tapped the holes in the spacer plate with a 10-32 tap and installed two 10-32 x 3/4” stainless steel cap screws.  The fore end sets nice and tight onto the rifle.

 

I rounded the sharp edges left when I cut the fore end to blend with the spacer plate, then sanded it smooth with 320-grit sand paper.

Applying a Camouflage Pattern with Spray Paint

 

I decided to camouflage the rifle with spray paint.  Rust-Oleum® makes a line of flat camouflage spray paint that can be applied to almost any surface.  Amazon.com sells a camouflage spray pack #269038 consisting of two cans of forest green, two cans of earth brown, one can of army green, and one can of khaki. 

 

From my local Home Depot, I purchased Rust-Oleum self-etching gray primer #249322, moss green #249071, rustic orange #314753, satin hunter green #7732830, and matte clear #285093 spray paints.  The primer will cover the entire rifle, flat white will add texture to the sticks, and the green and orange paints will provide additional autumn colors to the leaves.  Once the paint cures the matte clear will protect the finish.

I got some camouflage ideas by watching a few YouTube videos:

·         https://www.youtube.com/watch?v=jCGIE6dHFtg&t=331s

·         https://www.youtube.com/watch?v=Z5RM-ihRawQ&t=331s#t=59.0098912

·         https://www.youtube.com/watch?v=UgACuGtC3ow

·         https://www.youtube.com/watch?v=d5z2hEWBUT8

·         https://www.youtube.com/watch?v=vJNRGr7r5WY

I really liked the first video where he used pine needles to make a “sunlight in a dark forest” effect, which I decided to use as my background.  I also liked the sponge idea to add texture.

 

I found a small leaf stencil on the Internet which I printed onto a sheet of paper and cut out.  This stencil was for the small orange and green leaves.

 

I masked off the areas I did not want to paint.  The hardest part was masking all the holes in the receiver because I didn’t want to get paint inside.  I stuffed foam inside the receiver and muzzle, and a wooden dowel in the bolt opening.  I used 320-grit sand paper to rough up the wood, metal, and synthetic parts, then cleaned everything with acetone.  I applied a thin coat of Rust-Oleum self-etching gray primer to the entire rifle and allowed it to thoroughly dry.  I painted everything except the internal parts, screws, and the lever.  To me, the rifle with just the primer looked ugly!

 

I laid some pine needles onto the rifle and sprayed with bursts of the khaki paint.  I moved the needles so the resulting pattern was not going in the same direction and sprayed again with short bursts of khaki.  After one side was covered, I went back over the same side by laying the needles in a different direction and spraying with the deep forest green paint.  After each layer of paint, I used a hair dryer to speed up the drying process so I could apply the next layer of paint.

 

I laid the small leaf stencil onto the rifle and sprayed with army green, or orange.  After I dried the paint with a hair dryer, I flipped the rifle over and did the same process with pine needles, khaki and deep forest green paint, and the small leaf stencil and orange shaded with earth brown, and moss green shaded with army green to the other side.

 

After the paint dried, I went over one side of the leaf with a darker color because I wanted the leaves to have some shading.  I used army green on moss green, and earth brown on the orange leaves.

I flipped the rifle over and did the same process to the other side.  After the paint cured for about a week I applied two thin coats of matte clear to protect the paint.  After the clear coat dried I lubricated and reassembled the rifle.  I used Loctite blue on all the screws to prevent them from becoming loose.

Adding a Red Dot Sight

Rather than add a scout scope I decided to add a red dot sight.  Red dot sights are effective out to 100-yards, which is probably the farthest I will be shooting this rifle.  I prefer the type of sight that is completely enclosed in a tube because the tube prevents bright sunlight from washing out the dot.  Unlike a scope, a red dot sight has unlimited eye relief, which means I can set it anywhere on the rail.  I found a TruGlo red dot sight #TG8030A with a 5 MOA dot in a Realtree APG finish on ebay for a very reasonable price with free shipping. 

 

The knobs that came with the sight were tightened with a supplied metric allen wrench.  Who is going to carry an allen wrench in the field if you need to remove it and use the ghost ring sight?  I milled a 3/32” slot 0.140” deep in each knob so I could use a knife blade, coin, or screwdriver blade from a multi-tool pocket knife to remove the sight.  A shot of khaki and deep forest green covered the bright aluminum cuts.

 

I am very pleased with the finished result.  I guess I should be careful and not lay my rifle against a tree or I might never be able to find it!  One of my concerns is just how durable the paint finish will be.  I already discovered that Loctite blue removes the paint, and it scratches easily, but time will tell. 

Adding a Butt Cuff

 

MidwayUSA sells a buttstock cover by Beartooth Products that comes in Mossy Oak Break Up #203692.  It includes 5 foam pads of different thicknesses to raise the comb to fit different shooters for use with scopes or red dot sights.  It also includes 6 cartridge loops for spare ammo.

Bore Sighting

Bore Sight Calculator

Sight Height (inches)

Angle of Departure

Laser Position @ 25'
(inches)

1

0.063661951

0.7

 

 

 

Angle of Departure Calculator

Sight Height (inches)

Distance to cross line of sight (inches)

Angle of Departure

1

900

0.063661951

Laser Bore Sight Data for Peep Sight

I used my laser bore sight calculator to initially sight in both the peep sight and the red dot sight.  I used the data from the Remington web site for their .30-30 170 grain Core-Lokt cartridge.  Remington states the muzzle velocity for this load is 2200 fps with a ballistic coefficient of 0.254.

Using Sierra Bullets Infinity version 6, with this load sighted in at 100-yards and the 1-inch fiber-optic front sight, the bullet would cross the line of sight at 25-yards.  When I entered this data into my calculator it showed that the front sight would have to be 0.7-inches below the laser dot at 25-feet, i.e. the laser dot would be 0.7 inches high with the sights aligned with the center of the target.  I adjusted the receiver-mounted peep sight for this setting.

Bore Sight Calculator

Sight Height (inches)

Angle of Departure

Laser Position @ 25'
(inches)

1.84

0.06507666

1.5

 

 

 

Angle of Departure Calculator

Sight Height (inches)

Distance to cross line of sight (inches)

Angle of Departure

1.84

1620

0.06507666

Laser Bore Sight Data for Red Dot Sight

The TruGlo red dot sight sets about 1.84-inches above the bore.  The bullet would cross the line of sight at 45-yards.  Using this data showed that the red dot would have to be 1.5-inches below the laser dot at 25-feet, i.e. the laser dot would be 1.5 inches high with the sight aligned with the center of the target.  I adjusted the red-dot sight for this value.

These values should get my shots on paper at 100-yards.  I started at 50-yards and adjusted my sights to be 1/2-low, which brought my shots right on at 100-yards.

Summary
The takedown lever-action is not a new concept, although it has been made popular by Wild West Guns with their Copilot, which is a modified Marlin lever-action rifle.  I converted my Rossi ’92 .45 Colt rifle into a takedown rifle (refer to my article Building a Lever-Action Takedown Rifle) which was based on the article A Takedown Rifle found in The NRA Gunsmithing Guide – Updated published in 1982, so the process has been around for a while.

After all the work was completed and with the red-dot sight installed, the rifle weighed 7.25 pounds; just under Col. Cooper's requirement.

Marlin 336 Year of Manufacture
The following table can be used to date the year of manufacture of a Marlin 336.  It is also valid for determining most other Marlin firearm build dates from 1946 to the present.

Marlin year of manufacture maybe determined from the following table of letter/numeral prefixes to the serial number:

 

Date

Prefix(s)

 

 

Date

Prefix(s)

 

 

Date

Prefix(s)

 

1946

C

 

 

1955

M

 

 

1964

Y,

Z

1947

D

 

 

1956

N

 

 

1965

AA

 

1948

E

 

 

1957

P

 

 

1966

AB

 

1949

F

 

 

1958

R

 

 

1967

AC

 

1950

G

 

 

1959

S

 

 

1968

AD,

68

1951

H

 

 

1960

T

 

 

1969

69

 

1952

J

 

 

1961

U

 

 

1970

70

 

1953

K

 

 

1962

V

 

 

1971

71

 

1954

L

 

 

1963

W

 

 

1972

72

 

Starting in 1973, the year of manufacture can be determined by subtracting the first two digits of the serial number from 100: Example: SN 2512345 would have been made in 1975 [100 - 25 = 75].

 

 
   © Copyright 2017 Roy Seifert.