First range visit and a question

[Billygoat]

I finally got a chance to fire my new XCR-L — a 16 inch 300 blackout with a buried piston. Put 60 rounds through it… about 50 supersonic factory loads from three different manufacturers and about ten subsonic rounds, as well as three different magazine manufacturers.

Supersonics run at piston setting 7. No failures to fire/eject. I set piston to 0 and it turned into a single shot with the ejection port not opening -- just as it was supposed to.

The only issue I had was with subsonics. The bolt did not lock back in open position after the last round was fired. This happened on both piston setting 1 and setting 7. Does anyone know if this is the nature of subsonics or should this be remedied with a longer break-in period?

I cannot really comment on accuracy. I struggled quite a bit with the Troy Micro front sight. I think I have it under control now. I should have a better idea on my next visit to the range about accuracy. I also realized my eyes just are not what they used to be and I cannot reliably hold at a 100 yard target with any clarity at least to try to estimate MOA. I guess I will have to get some sort of glass. More money.

Prior to shooting, I was a little apprehensive. While there has been plenty of negative comments about this platform on the web, I did not encounter any issues other than the subs not locking back. Eventually, I will be turning this into an SBR and installing a dedicated suppressor when it gets out of NFA jail. I am looking forward to putting it more through the ringer. If all goes well, I plan on a second barrel in 6.8 SPC.

I was shocked at how light the recoil was. Felt like a toy. Of course, this is coming from an old mule deer hunter that does not even own an AR. Fun gun.

Thanks to Nate for acquiring this weapon for me.

[Merlin]

This might not be the issue but look at the bolt hold open lever and the spring. It might not quite be enough gas though to push the bolt back beyond the catch. Also try lubing the heck out of it until you have some more rounds through it to wear in the reciprocating parts.

[navalbeaver]

Subs without a can?

With a can I'm getting lock back on setting 2.

[mjorin]

Mine runs on setting 3 with can and lock back, but 10 inch barrel (IIRC).