Friday, January 6, 2012

Colt 1991A1 Upgrades and Trigger Job

The Colt 1991A1 is at its core a series 80 1911 with a parkerized finish.  What separates the series 80 from the series 70 is a firing pin block added to the series 80 models to (hopefully) prevent an accidental discharge should the gun be dropped or the hammer fall without the trigger being pulled. 

When I originally purchased my Colt, I was new and very naive to 1911.  I had fired a few here and there but didn't really understand what made one different than the others.

I quickly realized that it is the little details that separate one from the next.  The gun came with staked mil spec style sights.  They were difficult to use.  I had my local range mill new sights on the gun.  Now it is much more user friendly on the visual end.

However, the trigger was kind of stiff and heavy.  Additionally, I didn't care much for the kick.  Compared to other 1911s I had fired, it kicked quite a bit.  I asked around on one of the gun forums I frequent (I am up to 3 now I believe) about what could be done to remedy these issues.

I was given some really good advice and I followed it as best I could.

I had asked about changing out the recoil spring for a heavier recoil spring in an effort to reduce the recoil.  I was informed that this would actually increase the perceived recoil and also open the gun up to cylcling issues as well as possibly limp wristing issues.  Additionally, full size guide rods were deemed to be only beneficial if they were substantial in weight and even then it was arguable as to how much good they did.

I decided to avoid this dillemma by replacing the recoil spring with a stock Colt 16 lb spring.  This way I know I am using what was intended.

I was also advised that I could replace the mainspring with a 19 lb spring for a reduced trigger pull.  While a heavier mainspring will slow the slide down a bit and reduce felt recoil, I opted for this as the trigger pull was pretty high.  I unfortunately did not measure it before I began my work.

The subject of firing pin stops also came up.  The firing pin stop is not to be confused with the firing pin block.  The stop is the part that holds the firing pin in the back of the slide.  The original Browning design called for a squared firing pin block but for some reason or another, a bevelled firing pin block eventually found its way onto the gun and most guns to date have this bevelled style.  This changes where the slide contacts the hammer.  A higher point on the hammer axis/pivot gives more leverage and makes the job easier.  The squared firing pin stop lowers this contact point and reduces the slide velocity by making the slide work harder to reset the trigger.

I purchased an EGW oversized firing pin stop and carefully fitted it and put an ever so slight break in the sharp 90 degree angle of the firing pin stop to prevent it from destroying the hammer.  I was actually surprised at how easy the slide was to rack despite this upgrade.  This part required a lot of fitting.  In the end, I took my time and used a medium stone and was very pleased with how it came out although I did end up removing a lot of the finish from it while fitting it. 

While I had the firing pin stop off of the gun, I also took the firing pin, the firing pin block, and extractor out of the gun and replaced the firing pin block with one coated in titanium nitride from Cylinder & Slide as part of their series 80 trigger pull reduction kit.  This kit included 5 parts all coated in titanium nitride.  Those are the gold parts you see on the gun.  I was not trying to be fashionable.  Although I do think it looks good on the gun.

I replaced the hammer pin and the sear pin as well as they were a part of the kit.  The other two parts replaced from the kit were the two levers which disengage the firing pin block and allow the firing pin to move forward.  This was a very easy kit to install and everything was drop in.

I also took it upon myself to replace the trigger which was a plastic trigger with a Cylinder & Slide "Videki" trigger.  The videki trigger is a long style trigger with a serrated front and 3 holes.  It is made out of aluminum and required fitting.  Again I used a medium stone and took my time stoning each side of the trigger shoe until it slid into the frame.  There is now no vertical play like there was with the factory trigger.

When holding the pistol, I always noticed that the sights naturally sat to the side instead of dead on like my Beretta 92FS does.  It was then that I realized how important an arched mainspring housing was.  Some people like them and some don't.  I am a part of the definitely like them group.  

The mainspring housing was replaced with an arched model.  I went cheap on this and bought a no name part from CDNN and another no name part from Midway USA.  One had a serrated back and the other checkered.  Both were made out of steel and both required more fitting than I expected or would have liked.  The problem was that the hole that holds the mainspring housing into the frame at the bottom wasn't quite lining up with my gun.  I am going to blame the parts and not the gun.  I drilled the holes ever so slightly larger and managed to get the checkered mainspring housing in.  I like how it looks and feels.  It also brings the sights right up to my eyes just like my Beretta 92FS does!  I wish I would have known all of this prior to buying!

Lastly I replaced the grips with a cheap set from CDNN.  I like how they look and feel but I do not like how they fit the gun.  They do not fit the bushings that came on it very well and required some fitting.  I don't like fitting grips.  I don't know why, but I'd rather fit metal parts all day instead of grips.  I got them onto the gun, but I may end up replacing them later with real Colt brand grips just to avoid any issues in the future.  I will determine that later though after I have shot the gun some.

I didn't actually mind the original rubber grips either.  They were black and looked kind of cool.  But I am a big fan of wood so I figured why not?  When I removed the rubber grips, they were stuck to the frame from what appeared to be dried solvent/lube.  It was quite sticky.

All of the previous was primarily cosmetic or ergonomic.  The trigger job was what really set the gun apart from its former self.  I suppose trigger job is a bit of a misnomer.  I didn't sand or polish any internals on the gun.  There were no burrs to begin with and I felt that without a jig of some nature, I was bound to do more harm than good toying with stones and hardened parts.

The only part I adjusted was the sear spring.  The sear spring is a cool part.  It is just a leaf spring with 3 leafs on it.  One controls the grip safety, another for the disconnector/trigger reset, and the last for the sear.

Looking at the back of the gun with the grip safety removed and the hammer strut out of the way, the grip safety leaf is the one on the right.

The one in the middle is the disconnector and trigger reset.

The one on the left is the sear leaf.



With a trigger pull gauge, I slowly bent the middle leaf until I obtained just a little over 16 oz (1 lb) on the trigger pull before the sear leaf was engaged.  This was surprisingly harder than it seems.  The spring is thick and quite difficult to bend.  I tried to maintain the same natural curve as best I could and just reduce the tension on the trigger and disconnector.  This took a few attempts and finally I got it.

Then I did the same thing on the sear leaf.  This time I was shooting for a combined total of 32 oz (2 lb) from both the disconnector/trigger leaf and the sear leaf being engaged at the same time.  I came up a little high and decided to leave it at that.  Going too low can cause a lot of safety issues so I errored on the side of safe.

While bending the sear leaf, I did change its angle a little as the mainspring housing interfered with where I was bending and basically negated any adjustment I was making.  That is a good design for a safe stock gun, but not so good for tweakers like myself.  In the end, I bent just above the mainspring housing on the sear leaf.  Again, it took a few tries to get it right.

I reassembled the entire pistol and checked my trigger pull.  3 lb 10 oz.

I am very pleased.  The trigger is quite nice.  I'm sure it could be nicer if I had polished all of the internals and set up the overtravel screw, but I am just taking baby steps.

One thing that is important to note is that I also did a preliminary safety check on the gun.  I made sure the grip safety as well as the manual safety still worked.  I also rack the slide on an empty chamber a few times and checked to make sure the hammer didn't follow the slide or that the trigger didn't bound causing the hammer to fall.  I also dropped the slide with the slide release the same way.

I haven't taken it to the range yet, but when I do, I will start with 1 round in the magazine and fire.  Then if all is well, I will put 2 in the magazine and continue slowly working more rounds in until I am certain that the gun is safe.

Another important thing I should mention is that I will never ever carry this gun.  I have no doubt about its internal safety, but having a reduce trigger isn't necessarily a good thing for a carry/defense weapon.  And I am not just talking about legal liabilities should somebody get wind of a modified weapon being used in a defense shoot.  You don't need a hair trigger on a gun like that.

Honestly, if the trigger were much less than it is now, I don't even think I would like it.  Right now it is at the bottom of what I'd consider to be comfortable.