Alright, this is starting to eat a hole in my brain. Have a new to me JP ultra light Supermatch 18" rifle gas barrel that has been installed in a known to function upper/lower setup. Seekins lower, rifle buffer tube, Tubb flat spring, Seekins bolt release, ambi, Geissele match/match trigger. Upper is Daniel Defense, Seekins adj gas block and JP barrel and Young NM carrier. All of which ran without issues with 24" Satern barrel and ASC mags.
Forward to JP barrel install which has matched JP bolt. With fully open gas block, three different springs, two bolts, tested in another rifle setup that functions 100% and a carbine setup that is 100% with a mid length gas barrel, the bolt and carrier will only retract to the point it may/may not pick up next round, but will never get to full retraction to bolt catch, only just as far as back end of mag-maybe. Gas aligned, new gas tube, no sign of leakage. Hell of it is, other than enormous frustration, is that as I expected, the barrel itself shows it is accurate. But does not function. I'm stumped. Have built nice selection of AR's in 223, 6.5 Grendel and 6.5 Creedmoor, ALL of which function 100% and all are quite accurate.
At wits end. Seems to be slowed down at bolt catch, which I've smoothed contour of, but to no avail. Feels like something is too long, but can't seem to see where. Fact it's doing same thing in two other lowers leads me to barrel and/or gas block, but they seem to be correct.
Calling on long time expertise here for an assist. Thanks.
Forward to JP barrel install which has matched JP bolt. With fully open gas block, three different springs, two bolts, tested in another rifle setup that functions 100% and a carbine setup that is 100% with a mid length gas barrel, the bolt and carrier will only retract to the point it may/may not pick up next round, but will never get to full retraction to bolt catch, only just as far as back end of mag-maybe. Gas aligned, new gas tube, no sign of leakage. Hell of it is, other than enormous frustration, is that as I expected, the barrel itself shows it is accurate. But does not function. I'm stumped. Have built nice selection of AR's in 223, 6.5 Grendel and 6.5 Creedmoor, ALL of which function 100% and all are quite accurate.
At wits end. Seems to be slowed down at bolt catch, which I've smoothed contour of, but to no avail. Feels like something is too long, but can't seem to see where. Fact it's doing same thing in two other lowers leads me to barrel and/or gas block, but they seem to be correct.
Calling on long time expertise here for an assist. Thanks.
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