Maybe someone can shed some light on this for me.
I have had this upper for a few months. No issues. Shot around 150 rounds. Very accurate.

Decided to paint.. pulled hand guard off to paint barrel. Found barrel nut finger tight.
So I tightened it up w torque wrench and crows foot. All good. Finished paint job.
Cleaned up and oiled everything. I don’t paint bcg.

Took it hunting- 1st set took bullet fine. Called a blank set. Walked back to truck. Bcg locked forward. Had to mortar charge handle to get bullet out.

Ran rest of night- 6 sets, no issues.

Any ideas on what happened?

My only guess is when I tightened barrel nut it twisted barrel till pin stopped it and the bcg wedged on the lugs.

Can you tell us about your ammunition? Do you use factory ammo? Handloads?

My guess is ammo, either a case that didn't have the shoulder set back quite far enough for easy extraction, or the bullet jammed in the lands a little bit. Since you didn't pull the bullet from the case on extraction, my bet is the shoulder.

Factory loads varmageddon 55 gr

Been shooting same ammo since breaking barrel in.

It’s just weird that a problem showed up after tightening barrel nut

Is this a .243?

I'd take a marker and color your bolt lugs. If you reload make up some dummy rounds and completely color them with a marker as well. Manually cycle a few and check where the marker color wore off. I had some brass getting beat up pretty bad out of my BCA 243. I lighty filed and polished my barrel lugs. After doing so 99% of the dings and scratches on my ejected brass went away.

Factory ammunition can be out of spec. I have some Hornady Factory .223 ammo that was not quite right. It would fit in my bolt action but it was hard to close. Some of it was smooth during the cam over and some real stiff.

Do you have a headspace comparator gauge or a case gauge?

I agree with 204 AR on his assessment. In my experience, ARs (10/15) have more forgiving chambers.

Is your AR10 a .243?

TC

No- it’s a 22-250 upper from bca .
And as far as I can tell the brass isn’t getting beat up too bad. I do not reload. So I wouldn’t know exactly what to look at .

I'm glad to hear those are accurate, it is very tempting to try one.

Did you by chance chamber that same round for the next 6 sets? Or a different round each time?

I really don't know, it could be an out of spec round I guess like said above. You used a torque wrench, I can't see how you'd have caused any damage but if you think maybe you did It would be easy enough to check I guess. Unless the barrel pin spun enough to damage the slot in the upper it wouldn't be far enough off to cause a bind.

At this point I'd chalk it up to ammo still.

The first bca 243 I tried I used some of my hand loads I loaded long for my 700 VLS custom. I stuck one in the chamber and the bolt seized in place. I had to remove the upper and then creatively tap out the round. I measured my chamber and I was about a 1/4" longer than max OAL. I hand loaded .04" shorter than max AOL and never stuck once since in either of my 243 BCA uppers. You might have had a round loaded to long or the bullet backed out of the case during recoil. Besides the 90 grain FMJ seirras I jammed in my gun I've only tried 55 grain Noslers and 60 grain seirra HPs loaded over 4k. Both will shoot .3's with both bullets. I'll have to try some heavier projectiles some day. Never used either after my ladder testing. I also have CMC 2.5 pound single stage triggers in them. I wanted a 22-250 BCA but it would probably sit around like my 243’s. I'd rather use a lighter bolt gun when calling.

What brand magazine are you using? What is the mag capacity and how many are you loading? Also, the earlier question about whether or not your rifle cycled properly would be good to know. The 22-250 taper makes feeding a little bit trickier.

After the stuck bullet, I hunted rest of sets with same bullet. I did not rotate them.
I have also shot the rifle yesterday. 5 more rounds. With no issues. Was just checking zero for the weekend.


The magazine I use is BCA proprietary 22-250 modified amend
2 mag . It holds 10- mine never has more than 5 in it.

DP how do you like those CMC triggers? I am wanting to get that trigger for an old R25 I have.

Shooter I have not gotten around to messing with my 22-250 anymore. I need to try a different ammo like you suggested.

As most of the guys have stated, there can be variations even in factory ammo that could account for the issue that you ran into.

I doubt that tightening up the barrel nut caused the issue, otherwise you would have seen it on the rest of your stands and load/unload cycles.

As for the BCG and bolt lugs, again, I don't see that as the issue. With this being a 22-250 the ammunition could have been loaded either just slightly long (check your bullet for land and groove marks) or the shoulder or case might not have been full length formed for an AR platform. AR's are notorious for this. In other calibers that have been in the AR platform for a longer time, such as the .223, .308, etc you don't often see a problem. But I have a .204 that has a pretty tight chamber and it I didn't use a small base die when reloading I would have to buttstroke the ground to get the rounds back out of the chamber. They fired fine and ejected fine but just didn't want to come out with the charging handle without a bit of inertial encouragement. My buddy had a single shot NEF .204 and every round would go in and out of his rifle fine, but try them in my AR and it was buttstrokin time.