AR trigger improvement

RHarris · November 3, 2000, 12:40 AM

I'd like to improve the trigger on an Ar-15. I can't stand the rough heavy trigger it has and am not ready to spend a lot of money for a new drop in trigger.

I've read about this in other threads and am aware of the problems of the surface hardening getting removed.

If I do wear the surface down through the hardening, how long will it take until I discover I have done so? Is there any easy fix if too much of the surface is removed?

The engagement surfaces between the hammer and trigger seem to be the main cause of the problem. Will polishing the pin and other surfaces that move against each other really make much of a difference?

Any suggestions would be appreciated. I'm not trying to match one of those expensive drop in trigger assemblies, but what it already has is horrible. I'd be happy if I could just make the trigger feel like a trigger on a new out-of-the-box Marlin lever action.

CMOS · November 3, 2000, 09:42 AM

I've done a few "trigger jobs on my AR's before. You can indeed polish the engagement surfaces on the hammer and trigger but you MUST use super-duper mega fine sandpaper. By using this fine grit you will have to sand for days on end to remove enough metal to even approach removing the hardened surface. This also requires immense patience on your part. I would suggest you first pay more attention to the trigger surface than the hammer surface.

The key is to sand a small amount, reassemble, and try the trigger (you will learn to reassemble in less than a minute by the time you are half way done...). Also, and this is probably the most difficult part, you must not change the angle of the engagement surfaces. This, IMO, is the biggest reason why home done trigger jobs often get worse instead of better.

The good new is, if you screw up, triggers and hammers are plentiful and cheap!

I have done trigger jobs on all 3 of my AR's. 2 of them worked out very well, the third just got much worse. I finally gave up and just installed a Jewel Trigger (heaven!!).

Good luck.

CMOS

------------------
NRA? Good. Now join the GOA!

CMOS's Site

dZ · November 3, 2000, 10:04 AM

http://www.avalon.net/~middlecoast/riflesmo.htm
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>The AR-15 Rifle

Let's get one thing straight from the get-go. I love this rifle. I love everything about this rifle. I am so sick of people badmouthing this fine weapon that I won't even respond to the cliche'd sanctimonious
criticisms we all hear.

For the hunting I do in rural Iowa, it is the perfect rifle. If I were fighting commies on some long-range European battle field I would rather have an M-14. But the only long range commies I shoot at are
ground dwelling varmints commonly referred to as prairie dogs and my AR is just the ticket for them. If I could only have one self-loading rifle--not merely a theoretical exercise given the current
administration--and felt certain I would never leave rural Iowa, I'd take my AR. Now, if I had reason to believe I might find myself in Alaska, I might opt for an M-14 (M-1A).

Right out of the box this rifle is fine. Old boys around my neck of the woods have been sawing off carrying handles, free floating the barrels and low-mounting scopes on their ARs for years. These guys
use their ARs exclusively for coyote/fox hunting and this configuration makes a lot of sense for predator hunting. But I personally like the carrying handle and I can't say I've ever missed a shot because my
scope was mounted high.

Also, I've never seen a properly maintained AR that wasn't anything but absolutely reliable. So please take the smoothing I'm going to describe for what it is--tweaking. I have some friends who I consider
extremist audiophiles. These fellas spend $200 on speaker wire. They say if you turn the cable around and swap ends from the amps to the speakers it makes a sonic difference. That, my friends, is
tweaking. I'm sure they feel the same way about the procedures I'm going to describe.

Polishing the internals. I've never seen obnoxious tool marks on the feed ramps of an AR. But polishing without abrasives can't hurt. That's a good place to start.Ensure your weapon is unloaded and field
strip it. Wipe the chamber and all parts in the bolt carrier assembly free of oil. Leaving the upper and lower receivers separated observe the feed ramps on at the base of the chamber. Put a pointed felt tip on
the proper Dremel mandrel and sparingly apply Simichrome on the feed ramps. There is no reason to use sandpaper on the feed ramps so don't do it. We want to tweak, not alter.

Polish the feed ramps with the Simichrome and move on to jeweler's rouge. Don't spend a lot of time here, just polish to you can see the ramps start to glaze. This reduces friction for those incoming bullet
noses.

Next, examine the rails on the bolt carrier. You should see areas on the rails at the base and to the side of the bolt carrier key that appear worn and or shiny. These are friction areas. Smoothing here will
make everything work a little easier but again we just want to tweak. With the 600 grit paper go to work on any gouges and dings in these worn areas. Don't spend a lot of time with the sandpaper because
you don't want to remove much metal. Go on to the Simichrome and rouge and get those edges to shine. Your bolt carrier should move in and out of the receiver as if suspended on silicon bearings.

Turn over the bolt carrier and examine the bottom of the carrier. This is a high friction area as it contacts the top of the hammer during cycling. Go to work with the sandpaper and lessen any marks, dings or
gouges. Graduate to the Simichrome and rouge and smooth the whole surface until it shines. Don't worry about a few marks. Just better the worst of them.

Take a look at the bolt cam pin. This pin is also a high friction area. You'll notice several distinct wear patterns on this little pin. Start with the Simichrome polish and go on to the rouge. The wear marks
should sparkle.Polish the back of the bolt behind the gas rings with Simichrome and rouge. This part moves in and out of the rear of the bolt carrier during cycling and polishing in this area reduces friction.

The top of the hammer face, the surface that actually strikes the firing pin, is in contact with the bottom of the bolt carrier during cycling. Lightly sand here with the 600 grit sandpaper, paying particular
attention to any tool marks at the rear of the hammer face, and continue polishing with Simichrome and jeweler's rouge.

Improving the trigger pull

As I mentioned earlier, military-style rifles are not known for their trigger pulls. Usually they are gritty and can benefit by taking the roughness out of the hammer/trigger contact area. Please don't even think
about using sandpaper here. You can ruin your rifle if you use abrasives on the hammer/trigger contact area. Just polish this area with Simichrome and rouge.

With your thumb on the top of the hammer, pull the trigger and ease the hammer to rest against the back of the magazine well. Look down into the lower receiver and observe how the hammer assembly
goes together. Notice that the two arms of the hammer spring ride atop the trigger pivot pin. With your thumb on the hammer push the hammer pivot pin out to one side with a small nail or similar tool and
remove the hammer. Pay attention to how the hammer pivot pin comes out and put it back in the same way.

Wipe the hammer/trigger contact area on the hammer free of oil. Polish the contact area with Simichrome and then rouge. Spend some time here and get the contact edge/corner as polished as possible.
Don't bury the Dremel felt tip into the metal, keep the R.P.M.s up by letting the Dremel do the work. This area should be glass smooth. Then smooth the trigger/hammer contact edge on the trigger
assembly. You should be able to polish this edge with the trigger still in place. Wipe these area free of polish and oil liberally. Reassemble in reverse order of disassembly. Do not use force to seat the pivot
pin. You should be able to do this with finger pressure if everything is aligned properly. Check operation to ensure everything is reassembled properly but do not let the hammer smack into the back of the
magazine well.

Miscellaneous tweakage. There is no shortage of other improvements AR owners can make at minimal cost. For about $20 I installed a Trijicon tritium night sight front post. Granted this is beneficial only
at close range during low light conditions but I have occasionally stumbled across Mr. Coyote in that scenario.

If you generally rely on your iron sights, try to file the front post for more precise shooting. With the fine side of the file, take an equal number of strokes to both the right and left sides of the front post. By
removing a small amount of metal you can get a more precise sight picture. Touch up the exposed metal with a swipe or two from the touch-up black pen.

If you really want to squeeze precision from your AR consider installation of an aluminum forend that allows your barrel to free float. This reduces torsional effects presented when using a taunt sling and
when resting the forend on sandbags or a bipod. Eagle Arms, Box 457, Coal Valley, IL (309) 799-5619 offers everything from knurled aluminum forends to match sights and trigger assemblies to complete
rifles. If you really want to go all out, let technician Randy Farrell at Eagle Arms install a match barrel or 4.5 pound, clean-break-trigger group and transform your run-of-the-mill AR into a tack hammer.[/quote]

RobCon · November 3, 2000, 12:30 PM

I heartily endorse the JP trigger and speed hammer for the AR. JP Enterprises will install both for a nominal charge and their work is first rate. using issue Colt springs, mine breaks at 3.75 lbs. My Bushmaster Match gun has JP springs and breaks at 3 lbs. Good luck.

WalterGAII · November 3, 2000, 07:10 PM

Ditto on the JP hammer/trigger combo. I'm getting a really crisp, 2.5# pull, using JP springs. I also used a felt wheel on my Dremel and Simichrome to polish the engagement surfaces.

November 3, 2000, 12:40 AM	#1
RHarris Senior Member Join Date: June 18, 2000 Posts: 416	I'd like to improve the trigger on an Ar-15. I can't stand the rough heavy trigger it has and am not ready to spend a lot of money for a new drop in trigger. I've read about this in other threads and am aware of the problems of the surface hardening getting removed. If I do wear the surface down through the hardening, how long will it take until I discover I have done so? Is there any easy fix if too much of the surface is removed? The engagement surfaces between the hammer and trigger seem to be the main cause of the problem. Will polishing the pin and other surfaces that move against each other really make much of a difference? Any suggestions would be appreciated. I'm not trying to match one of those expensive drop in trigger assemblies, but what it already has is horrible. I'd be happy if I could just make the trigger feel like a trigger on a new out-of-the-box Marlin lever action.

November 3, 2000, 09:42 AM	#2
CMOS Senior Member Join Date: June 10, 1999 Location: TEXAS Posts: 1,417	I've done a few "trigger jobs on my AR's before. You can indeed polish the engagement surfaces on the hammer and trigger but you MUST use super-duper mega fine sandpaper. By using this fine grit you will have to sand for days on end to remove enough metal to even approach removing the hardened surface. This also requires immense patience on your part. I would suggest you first pay more attention to the trigger surface than the hammer surface. The key is to sand a small amount, reassemble, and try the trigger (you will learn to reassemble in less than a minute by the time you are half way done...). Also, and this is probably the most difficult part, you must not change the angle of the engagement surfaces. This, IMO, is the biggest reason why home done trigger jobs often get worse instead of better. The good new is, if you screw up, triggers and hammers are plentiful and cheap! I have done trigger jobs on all 3 of my AR's. 2 of them worked out very well, the third just got much worse. I finally gave up and just installed a Jewel Trigger (heaven!!). Good luck. CMOS ------------------ NRA? Good. Now join the GOA! CMOS's Site

November 3, 2000, 10:04 AM	#3
dZ Senior Member Join Date: May 31, 1999 Location: Exiled, Fetid Swamp, DC Posts: 7,548	http://www.avalon.net/~middlecoast/riflesmo.htm <BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>The AR-15 Rifle Let's get one thing straight from the get-go. I love this rifle. I love everything about this rifle. I am so sick of people badmouthing this fine weapon that I won't even respond to the cliche'd sanctimonious criticisms we all hear. For the hunting I do in rural Iowa, it is the perfect rifle. If I were fighting commies on some long-range European battle field I would rather have an M-14. But the only long range commies I shoot at are ground dwelling varmints commonly referred to as prairie dogs and my AR is just the ticket for them. If I could only have one self-loading rifle--not merely a theoretical exercise given the current administration--and felt certain I would never leave rural Iowa, I'd take my AR. Now, if I had reason to believe I might find myself in Alaska, I might opt for an M-14 (M-1A). Right out of the box this rifle is fine. Old boys around my neck of the woods have been sawing off carrying handles, free floating the barrels and low-mounting scopes on their ARs for years. These guys use their ARs exclusively for coyote/fox hunting and this configuration makes a lot of sense for predator hunting. But I personally like the carrying handle and I can't say I've ever missed a shot because my scope was mounted high. Also, I've never seen a properly maintained AR that wasn't anything but absolutely reliable. So please take the smoothing I'm going to describe for what it is--tweaking. I have some friends who I consider extremist audiophiles. These fellas spend $200 on speaker wire. They say if you turn the cable around and swap ends from the amps to the speakers it makes a sonic difference. That, my friends, is tweaking. I'm sure they feel the same way about the procedures I'm going to describe. Polishing the internals. I've never seen obnoxious tool marks on the feed ramps of an AR. But polishing without abrasives can't hurt. That's a good place to start.Ensure your weapon is unloaded and field strip it. Wipe the chamber and all parts in the bolt carrier assembly free of oil. Leaving the upper and lower receivers separated observe the feed ramps on at the base of the chamber. Put a pointed felt tip on the proper Dremel mandrel and sparingly apply Simichrome on the feed ramps. There is no reason to use sandpaper on the feed ramps so don't do it. We want to tweak, not alter. Polish the feed ramps with the Simichrome and move on to jeweler's rouge. Don't spend a lot of time here, just polish to you can see the ramps start to glaze. This reduces friction for those incoming bullet noses. Next, examine the rails on the bolt carrier. You should see areas on the rails at the base and to the side of the bolt carrier key that appear worn and or shiny. These are friction areas. Smoothing here will make everything work a little easier but again we just want to tweak. With the 600 grit paper go to work on any gouges and dings in these worn areas. Don't spend a lot of time with the sandpaper because you don't want to remove much metal. Go on to the Simichrome and rouge and get those edges to shine. Your bolt carrier should move in and out of the receiver as if suspended on silicon bearings. Turn over the bolt carrier and examine the bottom of the carrier. This is a high friction area as it contacts the top of the hammer during cycling. Go to work with the sandpaper and lessen any marks, dings or gouges. Graduate to the Simichrome and rouge and smooth the whole surface until it shines. Don't worry about a few marks. Just better the worst of them. Take a look at the bolt cam pin. This pin is also a high friction area. You'll notice several distinct wear patterns on this little pin. Start with the Simichrome polish and go on to the rouge. The wear marks should sparkle.Polish the back of the bolt behind the gas rings with Simichrome and rouge. This part moves in and out of the rear of the bolt carrier during cycling and polishing in this area reduces friction. The top of the hammer face, the surface that actually strikes the firing pin, is in contact with the bottom of the bolt carrier during cycling. Lightly sand here with the 600 grit sandpaper, paying particular attention to any tool marks at the rear of the hammer face, and continue polishing with Simichrome and jeweler's rouge. Improving the trigger pull As I mentioned earlier, military-style rifles are not known for their trigger pulls. Usually they are gritty and can benefit by taking the roughness out of the hammer/trigger contact area. Please don't even think about using sandpaper here. You can ruin your rifle if you use abrasives on the hammer/trigger contact area. Just polish this area with Simichrome and rouge. With your thumb on the top of the hammer, pull the trigger and ease the hammer to rest against the back of the magazine well. Look down into the lower receiver and observe how the hammer assembly goes together. Notice that the two arms of the hammer spring ride atop the trigger pivot pin. With your thumb on the hammer push the hammer pivot pin out to one side with a small nail or similar tool and remove the hammer. Pay attention to how the hammer pivot pin comes out and put it back in the same way. Wipe the hammer/trigger contact area on the hammer free of oil. Polish the contact area with Simichrome and then rouge. Spend some time here and get the contact edge/corner as polished as possible. Don't bury the Dremel felt tip into the metal, keep the R.P.M.s up by letting the Dremel do the work. This area should be glass smooth. Then smooth the trigger/hammer contact edge on the trigger assembly. You should be able to polish this edge with the trigger still in place. Wipe these area free of polish and oil liberally. Reassemble in reverse order of disassembly. Do not use force to seat the pivot pin. You should be able to do this with finger pressure if everything is aligned properly. Check operation to ensure everything is reassembled properly but do not let the hammer smack into the back of the magazine well. Miscellaneous tweakage. There is no shortage of other improvements AR owners can make at minimal cost. For about $20 I installed a Trijicon tritium night sight front post. Granted this is beneficial only at close range during low light conditions but I have occasionally stumbled across Mr. Coyote in that scenario. If you generally rely on your iron sights, try to file the front post for more precise shooting. With the fine side of the file, take an equal number of strokes to both the right and left sides of the front post. By removing a small amount of metal you can get a more precise sight picture. Touch up the exposed metal with a swipe or two from the touch-up black pen. If you really want to squeeze precision from your AR consider installation of an aluminum forend that allows your barrel to free float. This reduces torsional effects presented when using a taunt sling and when resting the forend on sandbags or a bipod. Eagle Arms, Box 457, Coal Valley, IL (309) 799-5619 offers everything from knurled aluminum forends to match sights and trigger assemblies to complete rifles. If you really want to go all out, let technician Randy Farrell at Eagle Arms install a match barrel or 4.5 pound, clean-break-trigger group and transform your run-of-the-mill AR into a tack hammer.[/quote]

November 3, 2000, 12:30 PM	#4
RobCon Senior Member Join Date: March 4, 2000 Location: Pennsylvania Posts: 149	I heartily endorse the JP trigger and speed hammer for the AR. JP Enterprises will install both for a nominal charge and their work is first rate. using issue Colt springs, mine breaks at 3.75 lbs. My Bushmaster Match gun has JP springs and breaks at 3 lbs. Good luck.

November 3, 2000, 07:10 PM	#5
WalterGAII Junior member Join Date: November 7, 1999 Posts: 1,516	Ditto on the JP hammer/trigger combo. I'm getting a really crisp, 2.5# pull, using JP springs. I also used a felt wheel on my Dremel and Simichrome to polish the engagement surfaces.