SBR Ejection Issues

[hafejd30]

Asking this as to see what your opinions are on my issue:

Just FYI I stole the image from google as I did not have my phone handy to take a pic of my issue but it’s identical to this.

10.5” PSA CHF Upper in 5.56

Jamming as shown in the pic below. Tried different mags with same issues.

Running a full auto BCG it would do this while ejecting Brass at 4oclock position.

Switched to a AR15 bolt carrier and had no issues for about 30-35 rounds and 6 mags. However brass eject forward now at about the 2 o’clock position.

Do you guys think I’m good to go with the AR15 bolt. Or is brass ejecting forward an issue. FYI the bolt failed to lock back on one mag when empty.

Just looking for a place to start. I’ve seen lots of possible fixes but figured with using 2 bolts you guys may be able to narrow it down a bit.

Thank you

 

[aslrookie]

Your first mistake is buying a PSA upper. Now that has been said, what ammo are you using? It sounds extremely inconsistent if you’re not playing with different buffer weights or adjustable gas block.

 

[hafejd30]

Probably should add I was using Fiocchi 55 fmj

Bought it on sale just to have. The SBR is a 8” 300 blackout generally

 

[AMGtuned]

Is one bcg heavier than the other? Could the weight, combined with recoil spring, be causing the jam due to cyclic speed?

 

[hafejd30]

The bootleg is the FA bolt. Which is having the issue

Other is a Bravo company I believe. Pulled from another upper

I think I’ll pull the bolt head on the bravo and try on the bootleg. See what I end up with for results

At least get weak ejector/extractor out of the mix

 

[hafejd30]

Is one bcg heavier than the other? Could the weight, combined with recoil spring, be causing the jam due to cyclic speed?

Posted a pic of them. I’ll weight them up. The AR bolt I’m assuming is heavier than the FA

 

[AMGtuned]

Posted a pic of them. I’ll weight them up. The AR bolt I’m assuming is heavier than the FA

I see that now. Posted at the same time. Be my first guess; gas system being equal

 

[TheGerman]

If you start seeing the bolt not locking back on an empty mag its leaning towards your buffer weight needs changed.

The doublefeeds can be a few things, but if its happening with different mags and mostly goes away when you change the bolt, its something with the bolt and/or bolt+buffer combo.

Not likely, but have you checked the headspace on each bolt? May end up being something weird where the headspace is off and the brass is 'growing' in the chamber, taking longer to extract and fucking the entire timing of everything up in the process.

I'm going with bolt+buffer combo if I had to guess.

 

[hafejd30]

Turns out my small scale I have doesn’t weigh up to as much as the BCG are.

I did just switch the bolt heads out tho. Ran 10 rounds flawlessly and ejected into very small area at 3 o’clock position. Thinking maybe I’ll run the other 40 through it tomorrow and see what the results are

 

[hafejd30]

If you start seeing the bolt not locking back on an empty mag its leaning towards your buffer weight needs changed.

The doublefeeds can be a few things, but if its happening with different mags and mostly goes away when you change the bolt, its something with the bolt and/or bolt+buffer combo.

Not likely, but have you checked the headspace on each bolt? May end up being something weird where the headspace is off and the brass is 'growing' in the chamber, taking longer to extract and fucking the entire timing of everything up in the process.

I'm going with bolt+buffer combo if I had to guess.

I checked them but (and I know your not supposed to do this per say) with a piece of scotch tape on a .223 gauge. I do not have a field gauge. But probably should invest in one....

 

[shoobe01]

If I read right, this is a classic type-3, not a true double feed: failure to extract the previous, then both that brass and a new live round try to both get back in the chamber.

Start with extractor cycle stuff:

• Does it eject well, and consistently, when not causing stoppages?
• Check for extractor damage, and make sure you have an o-ring around the extractor spring; it is possible to loose the cartridge halfway out when springs or other things fail to work right.
• Then, onward to springs and buffers, etc as above. Do a check that it locks back every time (get a pile of mags with 1 round loaded each).

 

[hafejd30]

If I read right, this is a classic type-3, not a true double feed: failure to extract the previous, then both that brass and a new live round try to both get back in the chamber.

Start with extractor cycle stuff:

• Does it eject well, and consistently, when not causing stoppages?
• Check for extractor damage, and make sure you have an o-ring around the extractor spring; it is possible to loose the cartridge halfway out when springs or other things fail to work right.
• Then, onward to springs and buffers, etc as above. Do a check that it locks back every time (get a pile of mags with 1 round loaded each).

Ok,

Ejection is consistent

And I ripped both bolt heads apart an both are missing the orings... checked 2 other ones I have here and they both have them.

So I robbed the extractor with oring off of the other gun and will be trying tonight. I have to do some work at camp. So I’ll try there before my neighbors start complaining

So I will try:

Same bolt head and bolt I just ran 10 rounds with. With new extractor installed. I’ll run a box of 50 through with the mag I used when having issues and report back.

Thank you by the way guys! Didn’t expect so much good feedback so quick.

Will also try multiple mags with 1 round as suggested to

 

[jrhtx]

You have a lot of thing that need to be eliminated 1 at a time. shoobe is right to shoot 1 round at a time to check for bolt lock first. No offense intended but PSA has been known to have issues with parts and assemblies sometimes. Do you have a box of spares to experiment with?
Do those bolts function 100% in a known factory built upper (Colt, LMT, Wilson, BCM, etc)? On the same lower you are trying with the new PSA upper? If this is yes, some of the below doesn't apply.
Are you shooting quality ammo?
True 2:00 ejection says you are over gassed??
Are your bolt parts quality parts? Extractor, spring, rubber insert, and/or o-Ring, ejector, etc. Check to be sure you don't have a small piece of brass binding the ejector. Does it move freely in/out?
Have you checked the carrier key to be sure it is not lose, torqued to the carrier and is not leaking gas? Are you using proper amount of lube on the carrier. I have seen this on a friends "dry!" bolt carrier. Gas rings good? Be sure your mags are good and have been tested in other upper/lowers.
Now you need to move on the springs, buffers, is the buffer tube properly aligned and buffer or bolt dragging?
It shouldn't take you long if you have enough parts to play with.

 

[hafejd30]

If I read right, this is a classic type-3, not a true double feed: failure to extract the previous, then both that brass and a new live round try to both get back in the chamber.

Start with extractor cycle stuff:

• Does it eject well, and consistently, when not causing stoppages?
• Check for extractor damage, and make sure you have an o-ring around the extractor spring; it is possible to loose the cartridge halfway out when springs or other things fail to work right.
• Then, onward to springs and buffers, etc as above. Do a check that it locks back every time (get a pile of mags with 1 round loaded each).

*Update*

Original problem:
Ran 10 rounds in a 20 round mag with 3 fails. Prepared to run 3 rounds in 4 30 round mags to test the function. First 2 jammed up.

Switched the bolt as stated above. 100% with no FTE/Feed etc. Just had 2 o’clock ejection

Swapped bolt heads and ran original BCG that jammed up. 10 rounds out of same 20 round mag as before with no fails

Checked the extractor for the Oring and as stated above both extractors were missing them. So I’m lucky I have some extra stuff to try. So I pulled an extractor from another BCG that had a Oring and installed in current BCG (bootleg)

Off to camp with 6 mags and 60 rounds of same ammo used above.

- Ran 6 mags in a row of 1 round a piece. 100% locked back every time

Ran 3 rounds a piece through all 6 mags. Zero jams and locked back every time - 100%

Loaded the 20 round mag up and did rapid fire. Enough to get a bit of smoke going. Zero fails ran 100%

Went back and fired 1 round through each of the 6 mags. 100% lock back rate

Loaded the remaining 16 rounds in a 30 round mag and let loose on my steel target. 100% with zero fails.

60 rounds
6 mags
Zero Issues what so ever
3-4 o’clock ejection

Thank you everyone who made suggestions. Especially to shoobe01 as I think he nailed the issue. Now to find some orings for the other extractors!

 

[hafejd30]

You have a lot of thing that need to be eliminated 1 at a time. shoobe is right to shoot 1 round at a time to check for bolt lock first. No offense intended but PSA has been known to have issues with parts and assemblies sometimes. Do you have a box of spares to experiment with?
Do those bolts function 100% in a known factory built upper (Colt, LMT, Wilson, BCM, etc)? On the same lower you are trying with the new PSA upper? If this is yes, some of the below doesn't apply.
Are you shooting quality ammo?
True 2:00 ejection says you are over gassed??
Are your bolt parts quality parts? Extractor, spring, rubber insert, and/or o-Ring, ejector, etc. Check to be sure you don't have a small piece of brass binding the ejector. Does it move freely in/out?
Have you checked the carrier key to be sure it is not lose, torqued to the carrier and is not leaking gas? Are you using proper amount of lube on the carrier. I have seen this on a friends "dry!" bolt carrier. Gas rings good? Be sure your mags are good and have been tested in other upper/lowers.
Now you need to move on the springs, buffers, is the buffer tube properly aligned and buffer or bolt dragging?
It shouldn't take you long if you have enough parts to play with.

Just to answer some questions

The carrier is a bootleg with an mpi bolt I had already. Zero idea what the brand is

Everything is lubed, mags tested for years in other AR’s (I had until that boating accident)

Nothing loose, gas keys etc. actually staked very well on this carrier.

The bolt head was run in another AR only a few rounds. The BCG itself is brand new

Gas rings look good

 

[TonyTheTiger]

@hafejd30 your terminology is going to make it a bit hard for people to help diagnose..

 

[hafejd30]

@hafejd30 your terminology is going to make it a bit hard for people to help diagnose..

Any chance you could elaborate? I think the issue is solved. But I’d be happy to fix whatever it is your referring to

 

[MOUNTIC]

Just helped a guy out with the same issue a few weeks ago and he was having extraction issues like you. Only variable was no O-ring on the extractor spring. Put one on there and he gun is running flawless since. On some guns it is necessary to have that stiffer extractor spring.

Glad you got it worked out.

 

[TonyTheTiger]

Any chance you could elaborate? I think the issue is solved. But I’d be happy to fix whatever it is your referring to

When describing a problem and then the subsequent parts swapping you have to use the right names for things or it gets pretty hard to follow.

This is a bolt:

This is a bolt carrier:

And together they make a bolt carrier group (bcg):

You can change out a bolt or a carrier independently, but anytime you swap bcg's it means you changed out the whole unit.

 

[hafejd30]

When describing a problem and then the subsequent parts swapping you have to use the right names for things or it gets pretty hard to follow.

This is a bolt:
View attachment 7126509

This is a bolt carrier:
View attachment 7126510

And together they make a bolt carrier group (bcg):
View attachment 7126512

You can change out a bolt or a carrier independently, but anytime you swap bcg's it means you changed out the whole unit.

Yup sorry about that lol

I’m actually not a big AR person. More of a bolt guy. But I can see where me using the same terminology for every part would have a negative effect haha

Thank you!

Problem hopefully solved anyways, good thing you guys know what I’m referring to!

 

[jrhtx]

If I remember the number correctly you can get
No 60 o-rings at Home Depot plumbing Dept

 

[ramblr72]

Probably should add I was using Fiocchi 55 fmj

Bought it on sale just to have. The SBR is a 8” 300 blackout generally

If the lower was built to run 300BO, it could be running an H2 in the buffer. You might need to swap in a Carbine weight for the PSA upper to run.

 

[hafejd30]

It is PSA multi cal lower. Seems to be working as it should now. Extractor issue looks to be the culprit

 

[AMGtuned]

If the lower was built to run 300BO, it could be running an H2 in the buffer. You might need to swap in a Carbine weight for the PSA upper to run.

I ran a "H" when my lower was used (for a short period of time) for .300bo, kept same buffer when switching back to 5.56. It still runs mint to this day, behind a multitude of barrel lengths

 

[benchmstr]

Throw away your buffer and buffer spring...get a heavy duty JP carbine spring and a spikes st-t2 and it will be fine

Bench

 

[Centuriator]

PSA ... there is the problem.

 

[hafejd30]

PSA ... there is the problem.

I have Smith, Rock River, Daniel Defense as well. Wanted a beat around AR to chew up some junk ammo in. Just went with up for my 300 BO to try. Seems to be good now. I’ll update if not. Thanks guys

 

[Centuriator]

Well, you get what you pay for. To be sure.

 

[shoobe01]

I ran a "H" when my lower was used (for a short period of time) for .300bo, kept same buffer when switching back to 5.56. It still runs mint to this day, behind a multitude of barrel lengths

Same for me. My SBR AR has H and normal (though regularly replaced!) silicon chrome spring, runs like a top on 5.56, .300, and 9mm (!), all with and without suppressor. Some guns just run, others just do not.