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Cleaning Up a 1947 Marlin® 39A
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.

Ever since I can remember I have been fascinated with firearms.  Unfortunately, since my parents were not outdoors people nor sportsmen, my exposure to shooting was limited to the high school rifle team.  On my 21st birthday I purchased a .357 magnum revolver which began my journey into the world of shooting and firearms.

One of the guns I’ve always wanted to have was the Marlin® 39A lever-action .22 rifle.  Believe it or not, this desire began with an arcade game.  As a teenager I used to play a shooting gallery arcade game that simulated shooting bottles with a lever-action rifle.  I always thought that would be fun to do in real life so I started researching lever-action rifles.  At the time I did my initial research, lever-action rifles mostly came in .30-30 or .22 calibers.  The .30-30 was primarily used for hunting and would be too expensive for plinking (I wasn’t reloading at the time) so I concentrated on .22’s.  The one that kept coming up was the Marlin® model 39A.

The Marlin® 39A has been in continuous production longer than any other rifle in America , beginning in 1891.  Annie Oakley used one for her exhibition shooting.  Rather than being made of aluminum and plastic, this rifle is all blued steel and American black walnut.  Its 24-inch barrel and full length magazine tube allows me to load 26 short, 21 long or 19 long rifle cartridges.  Plus, I’ve always thought the takedown capability was very convenient, and also pretty cool.  This rifle was always more expensive than other .22s on the market, so over the years I’ve made do without a 39A.

Recently on I found a used, Marlin® 39A for $380; about twice the price for a new Brooklyn-made lever-action .22.  Prices for new and used 39A’s were running $475+ so I felt this was a good deal.  However, the fact that this rifle was built in 1947 (as indicated by the prefix letter D in the serial number), it did not have a hammer-block safety, and it came with a tang peep sight made this an outstanding deal in my estimation!

Initial Assessment
This rifle appeared to be in great shape.  There were some dings in the butt stock and forearm but these could be steamed out.  The metal and bluing were in excellent condition with just a bit of surface rust and a few dings and scratches, typical of a 60+ year old rifle.  It was also very dusty indicating that it had been sitting around for some time.  There’s really no way of telling how many rounds have been fired through this rifle, but the action was glass smooth, and after a thorough cleaning, the bore looked bright, and the rifling sharp.  This was not the light, aluminum and plastic lever-action .22 I was used to.  Instead, this rifle felt heavy and solid; just like my other big-bore Marlin® lever rifles.

Magazine Tube
As with any used gun that I purchase, I completely disassembled the rifle to give it a thorough cleaning and inspection.  The first problem I found was with the inner magazine tube assembly.  It had a slight bend about six inches up from the follower, and the retaining pin that held the knurled plug in the tube was too loose.  This inner magazine tube assembly was made out of aluminum, not brass, and there were grinding marks on the tube where the retaining pin holes were drilled which made me think it was a replacement.  Research on the Internet indicated that this year gun came with an aluminum inner magazine tube, so the replacement was period correct.

I disassembled the inner magazine tube and inserted a wooden dowel so I wouldn’t over-bend the tube.  I gently applied pressure on the bend which was easy to see because it was rubbed shiny.  I was able to get the tube fairly straight so it slid easily into the outer tube.  I’m wondering if this was done on purpose to prevent the tube from falling out, or sliding back in when loading cartridges into the outer tube.  I took a cleaning rod with a .45 caliber cleaning patch and thoroughly cleaned the inside.  It took about 6 patches to clean 60+ years of gunk, then I ran a lubricating patch through the tube.  

I reassembled the inner magazine tube and tried to replace the solid retaining pin with a roll pin but the hole was too large.  A larger roll pin would not fit in the notch in the outer magazine tube, so I installed the retaining pin and staked it in place with a prick punch.  To finish my fix I put a 5/16” O-ring in front of the knurled plug, which provided just enough tension to prevent the inner tube from falling out.

Re-Crown the Muzzle

As shown in the above photo, the muzzle crown was rough and pretty dinged up.  A poor muzzle crown will affect accuracy.  I decided to re-crown the muzzle, not only to make it look better, but to also allow for maximum accuracy.

A professional gunsmith uses a lathe to cut a new crown, but I don’t have a lathe.  I used a 79-degree crown cutter I purchased from Brownells to cut the crown by hand.  This cutter makes a recessed target crown, but I used a 1/2-inch diameter cutter – smaller than the diameter of the barrel – so I wouldn’t cut out to the edge of the barrel.  I installed the .22 pilot, handle, and a 1/2-inch stop collar onto the cutter.  The stop collar makes the cut smooth, rather than uneven with chatter marks.  In the photo above the stop collar is set back to show the cutting teeth.  I adjusted the collar so it was almost flush with the front of the cutter.

I lubricated the pilot and cutting teeth with cutting oil and turned the cutter clockwise.  I turned the cutter only in one direction; otherwise I could break the teeth.  I cleaned chips off of the cutter and muzzle and lubricated the cutter frequently.  I cut until the stop collar touched the front of the barrel.  You can see the nice, clean muzzle in the above photo.

After I cut the new muzzle crown I used a brass muzzle lap to final-lap the muzzle.  This ensured the lands and grooves were nice and sharp at the muzzle which results in improved accuracy.  I took the smallest brass muzzle lap and chucked it in my hand drill.  I put some 400-grit lapping compound on the end of the lap, and with the drill running at a medium speed, I pressed the round end of the lap against the muzzle and used a rotating motion with my wrist to ensure the muzzle was lapped evenly. 

Cutting the new crown left a sharp edge on the front of the muzzle.  I took a 400-grit stone and went over that edge just enough to smooth it down.  Finally, I blued the exposed crown with cold blue to prevent the metal from corroding.  I degreased the crown with acetone, plugged the bore, then immersed the muzzle in Van’s Instant Gun Blue for about 5 minutes.  I wiped off the excess bluing solution, then treated the metal with gun oil to stop the bluing process.  The above photo shows the result.


I didn’t really measure the trigger pull before starting this project, but I did want it lighter.  To reduce trigger pull first I replaced the hammer spring.  I removed the original hammer spring by pushing the top of the mainspring plate to the right until it slid out of the frame.  I installed a Wolff reduced power hammer spring that I ordered from Brownells.  In the above photo you can see the original hammer spring next to the installed Wolff spring. 

To further lighten the trigger pull I pulled up on the trigger return spring until it made light contact on the trigger.  After reassembling the rifle the trigger measured 2 1/2 pounds, and the rifle was easier to lever.  I pulled the bullets and powder from various .22’s I had to test if the lighter hammer spring would still pop a primer.  Of the three different types of .22’s I tested, the rifle fired the priming compound with no problems.  If you notice in the above photo there are two notches in the bottom of the receiver for the mainspring plate.  If the replacement hammer spring was not strong enough I could have used the forward notch thereby increasing spring tension.

Rear Sight
This rifle came with a fixed, non-folding, rear sight.  I removed the rear leaf sight by drifting it out of the dovetail from left to right.  I don’t really need two sights installed, and the leaf sight got in the way of the peep sight.  

I ordered a Marble Arms® replacement folding rear sight from Brownells #579-000-082 and installed it from right to left in the existing dovetail.  This sight does not use an elevator to raise the sight; rather there is a blade insert that slides up or down in a channel and is locked in place with a screw.  The insert has a white diamond and has two different notches, round and V; I used the V.  Plus, this sight is also windage adjustable.  Now I have the tang peep sight as my primary sight, and the folding leaf sight as a backup.  I keep the leaf sight folded down when using the peep sight.

Front Sight
The front sight blade came with a brass bead, but as I get older I have trouble seeing that little tiny bead, even after polishing it up with a drop of Brasso® on a cleaning patch.  I decided to replace the bead front sight with a post front sight.

Brownells sells a post front sight with a white line in the center for $30.  I decided to try to fabricate my own using materials I had on hand.  Brownells sells a 12-inch piece of 3/8” dovetail blank which used as the base for my new sight, and I had some 1/8-inch steel bar for the post.

I used CorelDraw® to design the front post, then exported the pattern to my CAD/CAM program.  I used my hobby CNC mill to cut a channel in the base for the post, and to cut out the base from the dovetail blank.  I also used the CNC mill to cut out the post from the 1/8-inch bar stock.  I silver-soldered the post into the channel I milled in the base, then milled a 3/64 groove in the front ramp of the post.  I bead-blasted the new sight, cold-blued it, then applied white appliance touch-up paint to the groove.  Refer to my article Fabricating a Custom Front Sight for details.

The dovetail base was just slightly larger than the dovetail in the barrel ramp.  I used my 65-degree dovetail file to file one side of the sight base until it fit.

Ghost-Ring Rear Sight
The fact that this rifle came with an original tang peep sight was one of the selling features for me.  The tang peep sight had a single, target aperture that folded forward out of the way so the peep could be used as a ghost-ring.  I find that a ghost-ring works well for my aging eyes, and I don’t have to worry about lining up a rear sight, front sight, and target.  My eye doesn’t really see the large aperture ghost-ring, but my brain does and automatically lines up the front sight into the center of the ghost-ring, so once sighted-in, where ever the top of the front sight is, that is where the shot will go.

However, this sight was not windage adjustable.  When I attempted to bore-sight the rifle with a laser I discovered I had to drift the front sight almost 1/8-inch to the left, which meant I also had to drift the leaf sight that much to the left as well.  This did not appeal to me and I felt it destroyed the aesthetics of the rifle, so I decided to replace the tang peep sight with a windage-adjustable ghost-ring.

I found three different types of peep sights for the 39A that were adjustable for both windage and elevation that I could use as a ghost-ring; two were receiver mounted and one was tang mounted.  Those three sights were:

  • XS® Sight Systems model ML00075– This is a receiver-mounted ghost-ring that comes with a square post front sight.  Although this sight is adjustable for both windage and elevation it is more of a modern hunting sight and didn’t really appeal to me.
  • Williams® Gun Sight Company Inc. models FP and 5D – These are also receiver mounted sights adjustable for both windage and elevation.  The 5D is the less-expensive model and does not have the locking micrometer adjustments of the FP.  To be used as a ghost-ring sight I would simply unscrew the aperture and use the threaded hole. 
  • Marble Arms® model 009827 – This is their tang peep sight #8 and it is designed to fit the peep sight holes in the tang of the older 39A models.  This was the most expensive of the three sights, but was also more period-correct, and adjustable for both windage and elevation.  I have this sight on a number of other lever rifles I own and prefer it over other styles.  To make it a ghost-ring I unscrew the aperture and use the threaded hole. 

I decided to replace the original 1947 peep sight with the Marble Arms® #8 sight.  The sight base and screws fit the predrilled and tapped holes perfectly.  I was able to adjust both windage and elevation so I didn’t have to play with the front sight.

Refinishing the Stock
This rifle came with a dark walnut butt stock and forearm with an oil finish.  However, over the years the wood had acquired some nicks and felt dry and rough to my hands.  I decided to refinish the wood to make it smoother and more attractive.  This is not a collectable, it is a shooter, but I wanted it to look good and function well. 

I removed the forearm by first driving out the magazine tube band pin.  I then removed the two forearm tip screws and pulled the magazine tube out of the rifle.  The forearm fell out in my hands.  I removed the butt stock by removing the tang screw and pulling the butt stock off of the receiver.

One of the goals of refinishing a gun stock is to remove as little wood as possible.  Over the years I have ruined gun stocks by over-sanding trying to remove old finish.  The secret is to use a good quality stripper so I don’t have to excessively sand the wood. 

I stripped the old finish off the wood by applying BIX® stripper that I purchased at my local home improvement store.  I applied the stripper with a brush by dabbing it on very thick and letting it set for 15 minutes, then I scraped off the excess stripper with a business card.  I applied a second coat of stripper and again let it set for 15 minutes.  I again scraped off the excess stripper with a business card, then scrubbed the wood with water and #2 steel wool as described in the instructions.

After stripping the wood I steamed out any dents by applying a wet washcloth to the bare wood and ironing the wet cloth.  This also raised the grain in preparation for sanding.

Once the wood was dry I sanded it with 400-grit sand paper.  I only wanted to remove the feathers raised from the steaming process, not alter the shape of the wood.  I wrapped a strip of 400-grit paper around a roll of soft leather.  The leather roll helps to maintain the shape of the wood without leaving any dents or flat spots.  The above photo shows the difference between the original butt stock and the stripped and sanded forearm.

I removed the sanding dust with a tack rag (an old T-shirt worked well) and applied a coat of Minwax® Gunstock #231 stain.  This stain goes on brick red in color, but when the excess is wiped off, it leaves a brownish-red color.

Over the years I’ve tried different finishes on gunstocks.  Each has advantages and disadvantages; some are easier to apply, whereas others are easier to repair.  My favorite is Birchwood Casey Tru-Oil®.  It is easy to apply, gives a beautiful soft sheen luster to the wood, it’s durable, and it’s easy to repair.  After the stain dried I applied three coats of Tru-Oil®.  I allowed each coat to dry for 12 hours, then went over the wood with 000 steel wool.  The above photos show the refinished fore end next to the original butt stock, but really don’t do justice to the result.

Before reinstalling the outer magazine tube I ran a cleaning patch through it to make sure it was cleaned and lubricated.  Very few people ever clean the magazine tube, which can accumulate dirt.  In fact I once had a lever-action rifle stop feeding and jam on me because the follower got jammed in a dirty magazine tube.  Wouldn’t you know it happened in the middle of a shooting competition!

When I tried to reinstall the outer magazine tube I soon discovered just how difficult this was to accomplish.  Because I had to install the forearm first which covered the magazine tube hole in the receiver, I couldn’t get the tube aligned in the hole.  My solution was to install the outer magazine tube until it touched the front of the receiver, then I took a pistol/revolver cleaning rod and inserted it into the cartridge feed hole in the receiver.  I used the cleaning rod to align the tube; it literally took 5 seconds to wiggle (gunsmithing technical term J) the rod while pressing on the magazine tube until it clicked in place. 

Butt Plate

The butt plate had a number of chips around the holes probably because this was not an original butt plate and the countersinks didn’t fit the screws.  There was a large chip missing from the top of the butt plate as you can see in the above photo.  Since this butt plate fit the stock I really didn’t want to purchase a new one and go through all the fitting, so I decided to try to repair it with epoxy.

First I took a countersink bit and trimmed around the holes.  This allowed the screws to fit better.  Then I sprayed some release agent I purchased from Brownells around the top screw and mounted the pad to a piece of 2x4.  The release agent prevented the epoxy from sticking to the screw.  I read somewhere that Pam® cooking spray makes a good epoxy release agent, but I’ve never tried this.  I did not tighten the screw because I wanted to be able to rotate the butt plate.

I drilled two small holes in the hollow I planned to fill with epoxy.  This gave the epoxy some additional hold.  I mixed some J-B Weld® and added some black dye from a Brownells Acraglas® bedding kit, then applied the epoxy to the chipped area using a toothpick.  I made sure the holes I drilled were filled with the epoxy, and that the epoxy was higher than the surface of the butt plate.  In the above photo notice the cleaned up countersink around the bottom hole.  While the epoxy was curing I rotated the butt plate to prevent the top screw from getting glued in place.

After the epoxy cured I used 180-grit sand paper wrapped around a file and sanded it down flush with the surface of the butt plate.  Then I polished the surface with 400, 600, then 1000-grit wet/dry sand papers also wrapped around a file.  The file kept the sand paper flat and gave me more control when sanding.  Finally I used jeweler’s rouge on a felt wheel with my high speed rotary tool running at the slowest speed to final polish the butt plate.  I took the counter sink bit and cut away the excess epoxy from the screw hole.  As shown in the above photo, you can see the epoxy patch, but the shape is now nice and smooth.  I was actually very surprised how well this repair turned out.  I had thought about applying a coat of paint, but I decided not to because I felt the paint might flake off over time, and I wanted to show-off my repair.


The photo above shows the result of my work.  The wood actually came out a little lighter in color from the original, but you can see the semi-gloss finish from the Tru-Oil®.  

The real question is, however, how does it shoot?  Well, this is one sweet rifle to shoot, and I can see why it is so popular and still in production.  The action is smooth, the trigger is light and crisp, and it pretty much shoots into one hole.  The above target is 15 shots at 25 yards.  Overall I’m not only pleased with my work, but I’m very pleased with the rifle.  I’ll be shooting this one for many years.


   © Copyright 2010 Roy Seifert.