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Customizing a Kimber Pro Carry HD II
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
I received a very nice bonus at the end of 2015 so of course I bought a new gun!  When I was in high school I was a member of the school rifle team.  Our faculty advisor owned a Colt 1911 in .38 Super and allowed us to shoot it if we bought the ammo.  That was the first handgun I ever fired and I have wanted to add a .38 Super to my collection.

I have a number of full-size 1911’s in my collection in .45 ACP, 9mm, and .22 LR, but I wanted one in stainless steel, .38 Super, and Commander length.  To build one from parts would have cost me about $1,500 and over 60 hours in labor so I started to search the Internet to see if I could find a commercially made model that fit my specifications.  I finally found and purchased a Kimber Pro Carry HD II.

Kimber Pro Carry HD II
Kimber has developed an excellent reputation in the 1911 market and has many models to choose from.  The Pro Carry series of pistols have a 4-inch bushingless barrel which makes them 1/4-inch shorter than a standard Commander-length pistol.  The barrel is flared at the end so the barrel opening in the slide is wedged against the flare when the slide is in battery. 

The series II has a firing pin block that is released by the grip safety rather than by the trigger bow as in a Colt Series 80 so it does not affect the trigger pull.  Many shooters with series 80 guns remove the firing pin block because of how it affects the trigger, but I will keep mine in place. 

 

My research indicated that the HD may stand for “heavy duty” because the frame is all steel instead of aluminum alloy, and in fact mine is all stainless steel with a nice matte finish.  The gun came with molded rubber grips which seemed to enhance my grip on the gun, fixed Novak-style sights, and one magazine that holds 9 rounds.  This production pistol was tight; there was no slide rattle on the frame, and the bushingless barrel locked up to the slide perfectly which enhances accuracy.

Because the gun has a full-length recoil spring guide rod, to disassemble the gun I had to lock the slide open, insert the L-shaped takedown tool into the hole in the guide rod, then release the slide.  The tool keeps the recoil spring compressed so I can remove the parts from the slide.  I see this as being problematic in the field since I may not have that tool available.

 

My only dislikes were the fixed sight, the need for the takedown tool, the trigger shoe was too long for my hand, and the trigger had just a bit of creep.  Other than those minor squawks, this gun was ready to go right out of the box.  Because the firing pin block is connected to the grip safety I had to be sure I kept my hand off of that safety when removing or installing the slide onto the frame, otherwise the push rod would interfere with the travel of the slide.

Customization Plan
Although this gun was ready to go right out of the box, I wanted to make a few modifications of my own.  Most of these modifications wouldn’t really improve the gun but just my personal preferences.  My modifications would be to:

  1. Increase the secondary angle on the sear to remove the creep

  2. Replace the trigger with a medium-length trigger

  3. Adjust the trigger for pre-travel and over travel

  4. Checker the front strap

  5. Install a bobtail mainspring housing

  6. Checker the bobtail mainspring housing

Because I’m going to take a file to my new gun this will probably void Kimber’s excellent warranty.  However, this really doesn’t bother me since I can replace/repair most problems I encounter with a 1911 pattern pistol.

Removing Creep

The trigger pull on this gun really wasn’t bad; it broke cleanly at 5 pounds but had just a little bit of creep.  When I examined the sear it looked like it had a very small secondary angle; the width of this angle should be 0.020”.  I installed the sear into my Marvel 1911 Sear/Hammer Jig #080-823-000 and following the instructions that came with the jig, used a medium-fine ceramic stick #080-721-604 to increase the angle.  The trigger is now nice and crisp with no creep.

Replacing the Trigger with a Medium-Length Trigger
My hands are not very large so I don’t like having to stretch to get the first pad of my trigger finger on a long trigger.  Fortunately, Nighthawk Custom sells short, medium, and long length adjustable triggers.  I purchased a medium-length adjustable trigger #333149 from MidwayUSA.

 

This was not quite a drop-in part; it required some fitting.  To get the trigger shoe to fit in the frame I had to polish the top and bottom as shown by the white arrows in the above photo.  I only had to rub the top and bottom faces across 400-grit wet/dry sand paper about 20 times to get the trigger to fit and move smoothly with no up or down movement.  This results in a consistent trigger pull.

Adjusting Pre-Travel and Over Travel
The trigger came with pre-travel adjustment tabs as shown by the blue arrow and enlarged inset in the above photo.  There was one tab on each side of the trigger bow.  To adjust pre-travel, I bent the two tabs out just a bit and reassembled the gun.  With the hammer in the half-cock or safety notch position the trigger should not move.  If the tabs are bent too far out the grip safety will no longer function.

The trigger came with an over travel adjustment set screw shown by the green arrow in the above photo.  I installed the set screw into the trigger with Loctite blue.  To adjust over travel, I turned in the screw until the safety notch on the hammer just touched the sear when it fell, then backed the screw off 1/8 turn.  This was a trial and error process; the steps are as follows:

  1. Cock the hammer.

  2. Turn in the over travel adjustment screw 1/4 turn.

  3. Hold the hammer with two fingers, pull the trigger, and allow the hammer to gently fall.

  4. Repeat steps 2 and 3 until the safety notch on the hammer just touches the sear when the hammer falls.

  5. Back off the adjustment screw until the safety notch no longer touches the tip of the sear when the hammer falls; over travel is now adjusted properly.

Checkering the Front Strap
I like the positive grip that a checkered front strap provides.  I purchased a 20 lines-per-inch checkering file #080-310-401 and the Marvel Precision 1911 Auto EZ Checkering Fixture #588-100-011.  The checkering fixture is an expensive tool, but ensures I get nice straight lines.

 

I completely stripped the frame and installed the fixture onto the grip screw bushings.  Following the included instructions, I set up the fixture to make the relief cut in the frame.  The relief cut serves as the border for the checkering and allows me to take full strokes with the checkering file.

I used the 3/16 file that came in the Kart Precision Barrel XAct Fit Tool Kit #472-015-000 to file the border about 0.030” deep.  I could have used a flat jeweler’s file instead of the Kart file.  This left a sharp edge at the top of the border underneath the trigger guard which I will file/grind smooth after I finish the checkering.

 

I reset the fixture to make the vertical cuts.  I installed a plastic tie wrap in the border to prevent the file from moving too far, and covered the exposed trigger guard with three layers of masking tape.  This prevented me from scratching the frame in case my file slipped.  I rotated the jig around the circumference of the front strap and cut the vertical lines.  I cut until the file skidded along the metal and wouldn’t cut anymore.  This process takes hours to complete and should not be rushed.  “Patience is a virtue” as they say.

 

Notice in the above photo how I scratched the front strap of the frame under the trigger guard.  I had to remove the cable tie to get nice, even lines.  These scratches will be removed when I blend and polish the sharp edge of the border. 

After the filing was completed I used a small, triangular file to clean up each line.  I was careful not to allow the file to skip across a line.

 

I set up the fixture to make the horizontal cuts and cut down the length of the front strap.  I again cut until the file would not cut any more.  As I moved the fixture down the frame I was sure to keep the file lined up with the prior cuts.

 

After cutting the horizontal lines I again cleaned them up with a small triangular file.  I coated the checkering with a blue marker and went over all the horizontal and vertical lines once more to ensure they were all even.

I used my 6-inch narrow pillar file #191-400-760 and filed a border on the bottom of the frame.  I wrapped some 400-grit wet/dry sand paper around the file and polished the border until it was smooth and all filing marks were removed. 

I then used my Dremel tool and a fine sanding drum to smooth the top ledge of the border under the trigger guard, then used 400-grit wet/dry sand paper and “shoe shined” under the trigger guard to remove and smooth out the grinding and filing marks.

Finally, I put the frame in my bead blaster and blasted it with glass-bead media to get the same matte finish as the factory.  This process also dulls the sharp points of the checkering just a bit so they don’t dig into my hand so much.

Checkering the Bobtail Mainspring Housing

 

To make this gun more carry friendly I wanted to round the bottom rear corner of the mainspring housing and frame.  I had never performed this process before and wanted to add it to my skill set.  I purchased an Ed Brown smooth, stainless steel bobtail mainspring housing #168206 and installation fixture #259442 from MidwayUSA.  The smooth housing came with all the internal parts, and was $25.00 cheaper than the checkered version. 

I wanted the new housing to be checkered like the front strap of the frame.  It was cheaper to do the checkering myself than pay for a factory checkered one.  I installed the mainspring housing in my vise and used the bronze jaws as a guide to file the lines.  I cut the first set of lines using my 20 LPI checkering file with the housing deep in the jaws as seen in the photo above.  After the first set of lines were cut I positioned the mainspring housing above the jaws and finished the vertical lines.  The first set of lines acted as a guide for the rest of the vertical lines.

 

I repositioned the mainspring housing deep in the jaws so I could again use the jaws as a guide to file the first set of horizontal lines.  I then moved the file over 5 lines to cut the next set of lines.  You can see the result in the above photos.

Installing the Bobtail Mainspring Housing
There are a couple of videos on YouTube showing how to install the bobtail mainspring housing.  Installation requires drilling a new mainspring housing retaining pin hole and reshaping the frame and grips.  The instructions say to install the fixture into a vise, center a 5/32” drill bit in the top hole (this will be the location of the new retaining pin hole), insert the frame onto the fixture, lock it place with the retaining pin in the bottom hole, then drill the new hole.  The hole should be started with a center drill, then completed with the 5/32 drill bit.  The center drill has a thick shaft which prevents the bit from wobbling and wandering when drilling the smaller pilot hole.  If not done properly the drill bit will wobble and/or wander and the hole will be off-center or oval in shape.  One of the YouTube videos I watched showed how the user ovaled the hole because he allowed the bit to wobble, then he had to weld up the frame to correct his mistake.

I don’t have a center drill, although they are available on ebay at fairly inexpensive prices.  Without a center drill, there are a few methods I can use to prevent the bit wobble problem:

  • Install the drill bit deep into my chuck to prevent it from wobbling.  The shorter the length of the bit, the less chance for the bit wobble and wanter.

  • Plunge-mill the hole with a 5/32” square end milling bit.  I would only be able to mill one side, then use a 5/32” drill bit to finish the other side.  The fixture would act as a drill guide for drilling through to the other side of the frame.  This is the method I ultimately used.

  • Install the fixture on the outside of the frame to use as a drill guide for the first hole.  One YouTube video showed this method, but I would be concerned about not getting it aligned properly and being able to hold the jig in place.

 

I installed the fixture horizontally in my machinist’s vise and leveled it with a parallel.  Because the fixture was not in the center of the vise jaws I had to tighten the vise very hard to prevent the fixture from moving.  Yup, I learned this the hard way when the fixture rotated under the pressure of milling the first hole, and I had to stop and set everything up all over again!  Fortunately it didn’t mess up the hole.

 

I installed a 5/32 square end milling bit and centered it in the top hole.  This was a carbide, center-cutting bit so I could plunge mill the hole.

 

I installed the frame onto the fixture and held it in place with the hammer pin.  The hammer pin is the same diameter as the mainspring housing retaining pin, but the hammer pin has a lip that prevents it from falling through the hole.

 

I plunge-milled the first hole with the 5/32 square end bit.  I used very light pressure on the mill because I wanted the bit to cut and not bind or wander.  The bit cut through the frame as if it were butter.

After the hole was milled I removed all the internal parts from the new bobtail mainspring housing and installed it in the frame to ensure the new hole in the frame would line up properly.  I had to ream the new hole with a #21 drill bit to get the pin to fit, but it was lined up properly.

 

I reinstalled the frame onto the fixture and locked it in place with the hammer pin as before.  I centered a #21 drill bit in the top hole and drilled completely through the frame.  The fixture acted as a guide so the drill bit wouldn’t wobble.  The mainspring housing retaining pin fit perfectly through the new holes in the frame and in the bobtail mainspring housing.

 

The inside of the frame that I planned to cut off I painted with a blue marker.  I reinstalled the internal parts into the mainspring housing and installed the housing onto the frame with the retaining pin.  I took a sharp scribe and scribed around the mainspring housing.  This mark, which you can see in the above photo, told me where to stop cutting the frame.

 

I used my Dremel tool and a cutoff wheel to cut the corners.  I installed the mainspring housing in the frame and installed the retaining pin.  I used my Dremel tool with a fine sanding drum to shape and contour the sides to the bottom of the mainspring housing.  I didn’t mind grinding into the housing since I was going to finial polish the frame and housing anyway.

 

Once this was done I used strips of 400-grit wet/dry sand paper and “shoe shined” the back of the mainspring housing and edges of the frame until they were smooth and no grinding marks or divots were present.  I then bead-blasted the polished metal to match the rest of the finish on the frame.

If you look at the above photo you can just barely see two small divots at the bottom of the frame where it meets the new mainspring housing.  These were what was left of the original retaining pin holes.  The original holes were a bit farther in from the rear edge of this particular frame which left the two divots.  I don’t know if this is the same for all Kimber frames, or just my frame.  On a standard 1911 frame these small divots would not exist after blending the frame to the bobtail mainspring housing because the holes would be closer to the rear edge of the frame.

 

I trimmed the rubber grips to allow for the cut in the frame and the new location of the mainspring housing retaining pin.  The above photo shows the results.  The grip feels a bit strange in my hand because it is shorter, but this doesn’t seem to affect the handling characteristics.  The gun is very comfortable to carry, because there is no corner to stick into my side.  Overall I am pleased with the modifications I made to my Kimber Pro Carry HD II, but again, I have probably voided any warranty that came with the gun.

Failure to Feed
I put together some dummy rounds so I could test the function of the pistol.  To my surprise I got a failure to feed.  After successfully feeding a round 3 or 4 times, that same round got jammed under the extractor and would not allow the slide to go into battery.

When I examined the cartridge I found it had sharp grooves cut into the rim of the case.  These grooves were catching on the extractor hook which prevented the round from feeding.  I discovered this was caused by the sharp edges on the feed lips of the Kimber magazine as shown in the above photo. 

I pushed the follower down into the magazine with a pencil and held it in place with a pin pushed through one of the holes in the side of the magazine body.  I took a narrow 220-grit stone and stoned off the sharp edge.  I then took my Dremel tool with a Cratex bit to finish rounding and smoothing the edges.  Prior to doing this I couldn’t remove the first 3 rounds from the magazine with my hand.  Now the cartridges slip easily out of the magazine.  I purchased a second .38 Super magazine manufactured by Mec-Gar and found their feed lips were already rounded and smoothed.

 

 
   © Copyright 2016 Roy Seifert.