New build, jammed round in chamber - need help

[grayfox]

Warp, good to hear! this is progress.
In my case, for a new build, I load and shoot rounds one at a time for the first 50, from the mag and charging handle pulll-back-release (for consistency)... cleaning several times. (shoot 1 clean 1) X5 or ten, then shoot twice/clean 1 for next 10 or so.
I have had some round ftextract or fteject a few times but watch closely on the bcg, as to whether it cycles all the way back to the lock-back on the lower and not locking back on the mag... also I use those 50 or so to watch the ejection angle from the gun. All good info to have when you're breaking in a new rifle.

o, one more thing...always have a couple of spares, like maybe a used, "known-good" bcarrier you can swap in or even a "known-good" complete bcg. This can help in trouble shooting.

[Tex Nomex]

I second the Single Shot method for break-in. I usually do 40-ish rounds (2 boxes of something good).

[bj139]

New parts need more lube until they break in. It is the same with any machine parts.

I have been forming wildcat cases using a light film of resizing lube and assembling a new receiver and BCG.

I found resizing lube, rubbed on the bolt and inside the receiver makes it run slick.

[kcb38]

Glad to hear it's free but just wanted to add something for anyone else troubleshooting a stuck bolt in a new build, especially if you haven't assembled the upper yourself. I had one that was giving me fits trying to diagnose it and it turned out to be a broke / missing fwd assist spring. The FA pawl was coming out and jamming the bolt intermittently and it required separating the upper and lower halves to free it. That was fun, especially with the bolt not returning to battery and being partially in the buffer tube.