Problems

 

Shooting M855 from an SPR type rifle.  A2 rifle length buffer tube,  A2 buffer and spring,  ARFX skeleton stock, NiB full auto BCG, Basic milspec ALG FCG from PSA LPK.

 

1) Last round pops out of mag and jams 50% of the time

 

2) light primer strikes (fail to fire)

 

3) Brass ejecting at 1:00.  It used to eject @ 3:00

 

 

The last round popping out is probably mag related, but the rest I'm not sure.  The rifle performed well last year with the only problem being the last round issue.  Since then I also did a light trigger job.  I polished the contact surfaces to remove the grit, no filing at all.  I also put in a lighter trigger spring to lessen the pull weight.  I'm guessing that is related to the light primer strikes.  M855 has a pretty hard primer.  I don't have any 223 to shoot but I bet I would not have the problem with the softer primers used in 223.

 

I'm going to pick up a couple Magpul 10 rd mags, they seem to be very reliable, and see how that works out.  In the mean time, any suggestions about the other issues?

#1: Are you using a metal mag? One of the most insidious failures with metal mags is feedlip separation which results in feeding issues. Hard/impossible to detect without experiencing.

#2: Hammer spring might be too light. Try swapping it out.

#3: Did you change ammo? A sudden change in ejection pattern, especially going from perfect ejection to overgassed is odd indeed.

Most people don't have a problem using a full auto BCG, but the extra weight (although not much) might be the reason you are seeing poor ejection. Just a thought.

Try a new mag. 

 

Put back a real spring in the trigger group. The way you reliably lighten a trigger, is by buying a different trigger design,  putting lighter springs in the "milspec" trigger is asking for trouble. 

 

How many rounds through the gun and what type of barrel? You are shooting pretty gassy ammo which could give your overgassed ejection patterns. It could also be that you might have some gas port erosion and getting more gas into the gun.  It could be your recoil spring is worn out. 

#1: Are you using a metal mag? One of the most insidious failures with metal mags is feedlip separation which results in feeding issues. Hard/impossible to detect without experiencing.

#2: Hammer spring might be too light. Try swapping it out.

#3: Did you change ammo? A sudden change in ejection pattern, especially going from perfect ejection to overgassed is odd indeed.

 

I am using AR Stoner classic straight M-16 stainless steel 15/20 mags.  I crimped the lips on one of them but stupid me forgot which one.  I think it would be easier to just get a couple proven reliable Magpul mags to make diagnosing the other problems easier.

 

So far I've only shot M855.  I had 100 rds of 75gr 223 otm with me.  I was so caught up in fiddling with the mags and jammed rounds that I forgot I had the 223 ammo.  I want to go out again on Sunday so I'll be stopping by HGW to pick up a heavier spring.  The original spring that was in the lower is  now living in another lower.

 

Like I mentioned, only M855 through this rifle so far.  I agree that a one o'clock ejection pattern suggests overgas but nothing about the gas system has changed.  I am reluctant to believe overgassing is the problem.  I'm wondering if the work I did on the trigger has messed with the timing.

Most people don't have a problem using a full auto BCG, but the extra weight (although not much) might be the reason you are seeing poor ejection. Just a thought.

 

I would agree with that but it was ejecting at three o'clock before I fiddled with it. 

Try a new mag. 

 

Put back a real spring in the trigger group. The way you reliably lighten a trigger, is by buying a different trigger design,  putting lighter springs in the "milspec" trigger is asking for trouble. 

 

How many rounds through the gun and what type of barrel? You are shooting pretty gassy ammo which could give your overgassed ejection patterns. It could also be that you might have some gas port erosion and getting more gas into the gun.  It could be your recoil spring is worn out. 

 

Only about 300 rounds through it so far, nothing but M855.  The barrel is an 18"  Rainier 223 Wylde match with a mid length gas system.

Only 300 rounds, eh? You shouldn't be experiencing gas port erosion that quickly. But from the sounds of it, you changed the action spring? My money's on you having a tired or out of spec action spring. Change that out and see what happens.

Try a new mag. 

 

Put back a real spring in the trigger group. The way you reliably lighten a trigger, is by buying a different trigger design,  putting lighter springs in the "milspec" trigger is asking for trouble.

 

How many rounds through the gun and what type of barrel? You are shooting pretty gassy ammo which could give your overgassed ejection patterns. It could also be that you might have some gas port erosion and getting more gas into the gun.  It could be your recoil spring is worn out. 

 

Vlad I totally disagree with this statement.  JP Ent. Red hammer spring and yellow trigger spring can greatly improve a mil-spec trigger and still provide reliable ignition,

I am using AR Stoner classic straight M-16 stainless steel 15/20 mags.  I crimped the lips on one of them but stupid me forgot which one.  I think it would be easier to just get a couple proven reliable Magpul mags to make diagnosing the other problems easier.

 

So far I've only shot M855.  I had 100 rds of 75gr 223 otm with me.  I was so caught up in fiddling with the mags and jammed rounds that I forgot I had the 223 ammo.  I want to go out again on Sunday so I'll be stopping by HGW to pick up a heavier spring.  The original spring that was in the lower is  now living in another lower.

 

Like I mentioned, only M855 through this rifle so far.  I agree that a one o'clock ejection pattern suggests overgas but nothing about the gas system has changed.  I am reluctant to believe overgassing is the problem.  I'm wondering if the work I did on the trigger has messed with the timing.

 

Trigger work cannot effect timing.

 

And yes the lips on Stoner (Midways house brand) mags do spread in time.

Vlad I totally disagree with this statement.  JP Ent. Red hammer spring and yellow trigger spring can greatly improve a mil-spec trigger and still provide reliable ignition,

 

 

I've been down that path, I've used JP springs with milspec triggers and sooner or later they fail to ignite everything. Mind you, my threshold is "must light up crappy Wolf, just in case", if you are shooting Federal or whatever "good" primers then they work. 

 

Really, the market is FULL of awesome triggers that don't cost that much in the great scheme of things, life is too short to screw around with bulk parts and aftermarket springs. 10 years ago it made a bit more sense to try, today I don't think so. By the time you pay for the LPK, the springs, the test ammo, etc, you can just buy a better trigger.

 

But that's me, everyone can go down that path if they wish to repeat my mistakes

 

 

I've been down that path, I've used JP springs with milspec triggers and sooner or later they fail to ignite everything. Mind you, my threshold is "must light up crappy Wolf, just in case", if you are shooting Federal or whatever "good" primers then they work. 

 

Really, the market is FULL of awesome triggers that don't cost that much in the great scheme of things, life is too short to screw around with bulk parts and aftermarket springs. 10 years ago it made a bit more sense to try, today I don't think so. By the time you pay for the LPK, the springs, the test ammo, etc, you can just buy a better trigger.

 

But that's me, everyone can go down that path if they wish to repeat my mistakes

 

If that's your experience I understand your position.

But I've shot at least 1000 rounds over the past couple of years (that's accurate) Wolf and CCI primers and no failures to fire.

Your mileage may vary.

Repeat your mistakes?  Others may have my favorable experience.  You never know.

 

In reality the greatest improvement  in an AR trigger is one where the sear engagement is moved off the pivot point.

 

 

......

 

Really, the market is FULL of awesome triggers that don't cost that much in the great scheme of things, life is too short to screw around with bulk parts and aftermarket springs. 10 years ago it made a bit more sense to try, today I don't think so. By the time you pay for the LPK, the springs, the test ammo, etc, you can just buy a better trigger.

 

But that's me, everyone can go down that path if they wish to repeat my mistakes

 

Yes, the market is full of wonderful triggers.  My objective was to try and make a crappy milspec trigger better.  I did it to learn about how triggers work, it's a hobby.  I did not do it as a substitute for a professional grade trigger, and pretty much figured that I'd probably pooch the trigger and use whatever mistakes I made as a learning experience.  If I went and put a $150 drop in trigger in my rifle, It would probably work great, but I'd have learned nothing. 

Yes, the market is full of wonderful triggers.  My objective was to try and make a crappy milspec trigger better.  I did it to learn about how triggers work, it's a hobby.  I did not do it as a substitute for a professional grade trigger, and pretty much figured that I'd probably pooch the trigger and use whatever mistakes I made as a learning experience.  If I went and put a $150 drop in trigger in my rifle, It would probably work great, but I'd have learned nothing. 

PM sent

Yes, the market is full of wonderful triggers.  My objective was to try and make a crappy milspec trigger better.  I did it to learn about how triggers work, it's a hobby.  I did not do it as a substitute for a professional grade trigger, and pretty much figured that I'd probably pooch the trigger and use whatever mistakes I made as a learning experience.  If I went and put a $150 drop in trigger in my rifle, It would probably work great, but I'd have learned nothing. 

 

I get it, as I've said I've been down that path. 

Who's 855 are you shooting. Qc varies and it may just be a bit on the hot side. Check your primers.

 

This thread is leaning a bit zebra rather than horse when everything can be explained by a cheap mag wearing out and slightly high pressure surplus/3rd world 855 like ammo.

Who's 855 are you shooting. Qc varies and it may just be a bit on the hot side. Check your primers.

 

This thread is leaning a bit zebra rather than horse when everything can be explained by a cheap mag wearing out and slightly high pressure surplus/3rd world 855 like ammo.

 

I shoot Federal AE (Lake City) almost exclusively, but shot some Igman last year with no issues.  I was shooting Federal the last time out but it was a new carton so the lot was probably different.

 

The mags are virtually new.  Less than 100 rounds through each one.

Just as good as Colt.

I picked up a Magpul natural 15 rounder today.  The feed lips on the Stoner mags are about .045" of an inch wider than the Magpul.  Also picked up a new hammer spring.  It does not seem to be much stronger than the one I took out but I did notice that the legs (the part that rests on the trigger pin),  and the head (the part that rests on the hammer) were bent out of shape.  The new spring was perfectly straight 12 O'clock and 6 O'clock, the old spring was 12 O'clock and 4:30 O'clock.

 

I'm going to try and get out to R-14 again on Sunday and see what happens.