Locked Jammed BCG

Lil'Joe

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Minuteman
Aug 4, 2004
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Quick question, I have received a new M5 (308) upper from Aero Precision. When I close the dust cover, the rifle is jammed and I am unable to cycle the CH and BCG. It is locked up tight, and I must pry the dust cover open with a SS dentist pick to get it to cycle. I have submitted three tickets to Aero and they are very busy and have not contacted me. If I chamber a round putting the gun into battery close the dust cover and and fire the rifle with a rope, is this 50,000 psi chamber pressure going to harm the rifle? I wish that Aero would respond but they seem to be too busy
 
Well, for starters, don't attempt to test-fire weapons that are known to not function correctly if you think it may end poorly.

Assuming that Aero is like almost everyone else in the industry and too busy doing... something... to help their paying customers, you'll need to figure this one out on your own. Can we start by assuming that the bolt cycles fine if the dust cover is open? If so, then the issue is likely related to the interface between the dust cover detent housing and bolt carrier recess. Swap the cheaper part, test again, and you'll have your answer.

In the short term, you can run the gun without the dust cover with no problem. For the average user, the utility of that function is marginal at best.
 
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What BCG are you using? +1 on the dust cover plunger, I've had a few from Aero that were really tight initially. Some BCGs in the 308 family have sharper geometry around the scoop that the dust cover plunger fits into.

Can you see any rub marks on either the BCG or the dust cover?
 
1st guys thank-you for the feedback and I would never fire a rifle that is even slightly questionable. Am I the only one that has has this problem, with Aero or any of their equipment?

The rifle has an Aero upper, lower, BCG and CH. When the dust cover is closed with the BCG and CH installed, I am unable to cycle the rifle, in fact even with the lower removed. I am a formerly 500# bench presser, while more a balding old fatman today, I am still a bit stout and I am unable to pull the CH to the rear with the BCG and CH installed and the dust cover closed. I have inspected the BCG and see no marks of course, the rifle will not cycle with the dust cover closed. I first thought that the plunger was too tight but it depress the same as on my other AR.

This is really frustrating, I have submitted three tickets on this to aero on their website, in addition I have made three telephone calls and have been told that they have had more issues because they have increased production, that does concern me some. Seem like everyone that I speak with says it is not their job, and finally since everyone is working from home because of Washington COVID rules, they apparently have no way to communicate with each other???

Anyways bottomline, I guess I have no choice but to wait the out, until then, I have spent around $600 for a defective upper and the manufacturer does not seen interested in talking to me about it.

Again thanks
 
I'd do as E.Bryant suggested and remove the dust cover and leave it off the rifle until Aero can manage to get back to you - or just replace it with another dust cover. I seriously doubt things are going to get any less hectic at Aero Precision (or any other AR manufacturer in the near future), so the question becomes - do you want to be stuck with an unusable rifle and do nothing about it besides talk online, or would you like to actually be able to shoot the rifle?
 
Sorry I worked for many years to hit a 500# bench and well over 750# squat, not bragging because, I have trouble hitting my old warm-up lifts. Again not bragging, I started lifting weights in 1960 and did not hit a 440 # bench until the late 1990’s and go over 500#’s until 2006. That is 46 years. Back to my rifle, I will remove the dust cover, but I am still going to fire the 1st couple of rounds with a rope, the rifle will chamber a round, but maybe I should treat it like the upper is out of spec, and not fire it at las.
 
Thanks guys, I will try all of the suggestions. I have not tried to release the BCG with the dust cover closed to see if it will go into battery. Great suggestions I should have tried your recommendations 1st. BTW Aero did get back to me kind of almost. Too long a story and will not bad mouth anyone, so will drop it with there has been no plan moving forward to address my issues with the upper with the manufacturer. To those guys that pump iron on here, I would suggest very small quick gains and map them out over at least a year. To bench you must squat, my bench went over 400 when my squat went over 600, and went over 500 when my squat went over 725 - 750. Don’t hurry but do push it hard. OK enough unwanted advice. Good shooting and thanks again!
 
Thanks guys, I will try all of the suggestions. I have not tried to release the BCG with the dust cover closed to see if it will go into battery. Great suggestions I should have tried your recommendations 1st. BTW Aero did get back to me kind of almost. Too long a story and will not bad mouth anyone, so will drop it with there has been no plan moving forward to address my issues with the upper with the manufacturer. To those guys that pump iron on here, I would suggest very small quick gains and map them out over at least a year. To bench you must squat, my bench went over 400 when my squat went over 600, and went over 500 when my squat went over 725 - 750. Don’t hurry but do push it hard. OK enough unwanted advice. Good shooting and thanks again!
If it opens when you drop the bolt, more then likely the bcg is creating wedge with the dust cover. If this is the case, I would add dykem in the marked areas and test it from a closed bolt position.

I would take a thin file and creat a small grove in the detent to easy it’s function. If this is not enough I would then remove some material from the other area that I marked. removing the material will give the carrier a little more travel and stop the parts from wedging together.
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All I have to say is try another dust cover BEFORE you do any filing/grinding on anything.
Have you looked at the dust cover to make sure it's flat and not bent/bowed somehow?
I've only had "trouble" with some of my dust covers opening TOO easily, never imagined one could jam the bolt closed even when being fired.