PSA 10.5" with FN CHF Barrel with multiple Failures to Eject/Failure to Feed

[davisj]

I recently purchased a PSA (I know...) URG and selcted the FN CHF barrel hoping to avoid issues. I'm using a new BCM BCG and a PSA pistol lower with the SBA3. The buffer spring and buffer that came on the lower felt like they came out of a toy so they quickly went in a box. I had H1 and H2 buffers and a Springco Blue spring so I took these to the range today. I also have some milspec carbine springs but I forgot them at home. Ammo was Federal XM193 5.56. Magazines were one new PMAG 30, Gen 2 and 2x new D&H USGI 30 round magazines with Magpul followers.

Out of 60 rounds, I had five failures to eject/failures to feed and one failure to extract. Two of the six failures were with the H1/Blue and I only shot five rounds with that combo. The other four failures were with the H2/Blue with 55 rounds fired. I'm wondering if the combination of the Springco Blue with the heavier buffers were the problem.

Thoughts on what the root cause might be? I intend to return to the range with a milspec spring and the H1/H2 and try again. I don't have any good carbine weight buffers except for the stock buffer from PSA which sounds as smooth as gravel in an aluminum can when I shake it.

Link to PSA URG

I plan to get a BCM 11.5" URG when they get back in stock but I still believe this 10.5" FN CHF URG from PSA should be functional.

Thanks!

[inkslinger]

Did you try a lock back test to make sure it isn’t short stroking? And just throwing this out there, was it well lubricated?

[5pins]

Was it striping the top round in the mag but not feeding because the fired case was blocking it?

Was there any damage to the rim of the fired case?

[davisj]

The bolt locked back every time on the last round. Yes, it was well lubed. And no offense with the question.

[davisj]

Was it striping the top round in the mag but not feeding because the fired case was blocking it?

Was there any damage to the rim of the fired case?

Yes, it was stripping the top round but not feeding because the fired case was blocking it. There was no damage to the rim of the fired case that i could see with the naked eye.

[5pins]

It sounds like you have a bad extractor or it's very over gassed. Do you have another BCG or bolt you could try?

[davisj]

I have another BCM BCG with a few thousand rounds I can try. Also have another new BCM BCG that should be delivered this week.

I've been unable to find FN's gas port size online for this barrel length and checking it myself is beyond my skill level.

[5pins]

Try a different carrier next time and see what happens. If you still have problems take pictures and save the spent cases.

[davisj]

Will do, thanks for the suggestion.

[Casual Friday]

I have another BCM BCG with a few thousand rounds I can try. Also have another new BCM BCG that should be delivered this week.

I've been unable to find FN's gas port size online for this barrel length and checking it myself is beyond my skill level.

The gas ports on these barrels are to PSA's specs and at one time they were .080". I don't know if that's changed.

I would try those other two BCM BCGs and see if the problem persists. If not, look at the extractor spring to see if it's broken or worn out and replace with a Colt or Springco extractor spring. Even though it's new, a bad spring could slip through.