Another AR issue

jmccracken1214

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Shot my new to me, ruger sr556 yesterday. Shot some hornady brass and wolf steel ammo. Ran great. cycled everything fine, the issue is.. not locking back on last round. Tried gas at all 3 settings, it would do it every once in a blue moon. I took the buffer and spring out of another AR, it locked back a little more often, but not everytime. I put that buffer and spring back in the other AR and swapped lowers.... locked back everytime... What gives? same buffer and spring, worked in 1 lower, but not the other. That would leave only the tube to be suspect? but what goes wrong with a tube?

I ordered a bcm kit, new tube, spring and bufffer... hoping this will be the cure.
 
Cycling but no lock back?

1 magazine related
2 bolt catch out of spec
3. Magazine catch too loose in the lower
4. To much slop in the magazine well

1. I would number your mags, load 2 rounds in each and run them. Segregate based on performance. Run PMAG and metal USGI

2. Test 1 will help with this.

3. How many threads are exposed on the magazine release button?

4. If all else fails, add rearward pressure to the magazine and shoot two rounds. record. Then add frontward pressure to the magazine and shoot 2 rounds and record.
 
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Cycling but no lock back?

90% magazine related or bolt catch out of spec.

I would number your mags, load 2 rounds in each and run them. Segregate based on performance. Run PMAG and metal USGI
Tried 3 pmags, and 1 metal mag... With all ruger parts, it wouldnt lock back at all... when I put the other lower on, it locked back with every mag.

It will lock back manually though. Maybe bolt catch spring needs to be replaced?
 
Tried 3 pmags, and 1 metal mag... With all ruger parts, it wouldnt lock back at all... when I put the other lower on, it locked back with every mag.

It will lock back manually though. Maybe bolt catch spring needs to be replaced?

Ok,
Different now. Are the buffers the same OAL?
 
I used to have many many many problems with my built AR. Would not lock back on empty mag. Sometimes would only cycle enough to eject the spent case and would bend the cartridge being fed in half with the bolt.

Tried new buffer springs.
New buffer.
New gas tube.
New gas block.
Gas block "aligned" by a "professional"

Still had the problems.

Drilled my gas port on my barrel out to the exact hole size of the gas block.

All problems solved. Never had a single malfunction since.
 
Or since you're not DI anymore and don't know the last time it was shot/cleaned maybe that piston just needs some love and lube to get the pressure back to the bolt properly
 
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Another thought. Maybe the bad lever im running is causing issue. Ive read a lot of posts before of people having problems. Ill take it off and see.

I dont get that, but it is an issue.

Will report back later this week after I try again
 
I've run a BAD lever since I built mine. Any chance you could put one round in and get someone to slow-mo video shoot you shooting? That would tell you if the bolt was fully making it to the rear or not, and get you certain that it is either a gas issue or mechanical/spring issue. I wasted so much time replacing mechanical things when it was an easy gas fix. Best if luck!
 
I've run a BAD lever since I built mine. Any chance you could put one round in and get someone to slow-mo video shoot you shooting? That would tell you if the bolt was fully making it to the rear or not, and get you certain that it is either a gas issue or mechanical/spring issue. I wasted so much time replacing mechanical things when it was an easy gas fix. Best if luck!

I think I figured it out. Took the upper off, inserted a mag and watched the bolt catch. It'd go up, but I could move the bad lever and raise it some more... pulled one of my built lowers out of the safe, pulled the bolt catch spring and swapped it in. (its new) and put the bad lever back on, inserted a mag and the catch went all the way up, can't move it anymore upward.

Ill confirm when I shoot, but im 99.99999999999999999% that was my culprit.
 
Another thought. Maybe the bad lever I'm running is causing an issue. I've read a lot of posts before of people having problems. I'll take it off and see.

I don't get that, but it is an issue.

Will report back later this week after I try again

Yeah, bad levers are garbage. The 2007 good idea fairy wants its bad idea back.
 
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Took it out today to test. Cleaned the piston earlier in the week. Replaced the bolt catch spring and put the bad lever back on. Put the piston on 1, which is lowest amount of gas. Didnt expect it to lock back with wolf, but it did 4 out of 5 times. Put it on 2, where most people run it anyways. ran perfect.
 
Took it out today to test. Cleaned the piston earlier in the week. Replaced the bolt catch spring and put the bad lever back on. Put the piston on 1, which is lowest amount of gas. Didnt expect it to lock back with wolf, but it did 4 out of 5 times. Put it on 2, where most people run it anyways. ran perfect.
Glad it worked!
 
Yes that’s where I got it from. Flat rate $8.50 to ship it. So I got 7 pmags and paid the same 8.50 for it all shipped
Gotcha. I guess I'm spoiled with one 5 minutes from the house. If it happens again let me know and I'll drive to the store, pay the $1 put it in an envelope with a stamp for free.
 
Gotcha. I guess I'm spoiled with one 5 minutes from the house. If it happens again let me know and I'll drive to the store, pay the $1 put it in an envelope with a stamp for free.
I’d gladly pay you for that. I need to stop in and pick up spares when we pass it visiting in-laws
 
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