I do believe batch testing is just fine and I personally use a batch tested bolt in my OTD gun.
I have not purchased any new bolts from CMT for over a year so the bolt you have is most likely MP tested as at that time, everything was MP'd.
C4
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We have Colt's, Demaico's, and now Colt Canada guns at work.
I have a Colt 6920, Stag N8CQB, and an RRA 9mm at home.
I'm very happy with my Stag for a personal rifle, so much so that I'm going to sell the 6920 to fund other projects.
ATTENTION ROB!!!
I have to say that I love this post. I have a Colt M-16 A2 sporter (I have had for 18 years) and came across a good deal on a BM 14.5 M-4 Izzy. I shot the BM the first time out in Febuary to sight and function check......14 full 30 round mags (420 rounds) and 4 different brands of 55 gr. ammo. About 200 or so into the maiden run of this fun rifle, I had a double feed; an empty case with a live one wanting to come up the ramp. This was a fresh Remington green box round. (as opposed to Wolf which BTW functioned 100% thru 90 rounds).
Stunned, I said "I'm going to do a few Rob upgrades". My 2 brother-in-laws that were with me, 1 an absolute gun nut and the other a 12 year Army vet and very familuar with the M-16 both said "What! It's one failure in a break-in, its fine. Its probably just a bad round or magazine" I said "no way". "I will give this one more shake upon my next visit to the range, but if it fails then, I'm selling it". I own 2 GLOCKS that are 100% after a collective 4500 rounds, so I compare everything to GLOCK now. Anyway, I marked the supect mag with a marker and set it aside to try again next time.
Anyway, other than that we got it battle sighted (running stock iron sights) and produced a wonderful 3" round hole in the middle of the paper after it was all said and done. But I noticed that the next day my shoulder also had a bruise on it. Mind you, I probably only shot 200-250 rounds myself because my brother-in-laws were also shooting it and helping me sight it.
So off to the "Rob list" I went: H buffer and a crane black insert and O-ring from Bravo Company.....tossed in a few more mags and Gen II Magpul followers too :) (I think those green ones suck -they tilt too much for me)Installed the new buffer and upgraded extractor.
Fast foward to last month, my 2nd visit to the range with this rifle.... 15 full mags, 450 rounds now, 3 different 55 gr ammo; once re-loaded Lake City from a gun show, Tiawan PMC and another 90 rounds (3 full mags) of steel Wolf that all AR guys seem to hate. (Again, I'm a GLOCK guy, I feel that that firearm should eat everything). My point is, this is less than desirable ammo.
I'm by my self this time, so I will have to take all 450 rounds into my shoulder. How will I and the rifle fair this time? Remember, I will sell this POS if it fails again and I need to eleminate a possible bad magazine.
RESULT: AMAZING! 100% reliability, noticably less recoil and a nice tight pile of brass and steel about 8 feet from my 4 o'clock! The suspect mag which I intentionally loaded with the Wolf crap; 100%. The next day I did not feel a thing in my shoulder and NOT PHYSICAL SIGN on my body, i.e. bruise.
I attribute the wonderful function to the upgraded extractor (which I feel was the cause of the original double feed) and the H buffer (which I attribute to a comfortable shooting sesion - and maybe a slower bolt action) to a happy and trust-worthy rifle.
Thanks Rob! Its amazing what a $25 buffer and $3 extractor upgrade can do. ;)
grant just posted a topic on how to square away a bushmaster rifle. it more or less applies across the board to the STAG line of AR's also.
check it out.
https://www.m4carbine.net/showthread.php?t=13532
Very informative post for an EBR noob such as myself.:cool:
thanks rob this info you (and posibly friends) have collected and posted helped me out. now i have lots to check when i get home from IQ. and a way better understanding of the AR all together.
I just discovered this thread and wanted to know, can better parts (such as LMT) be put into a lesser quality gun without any issues? Or would the tolerances not match up?
I'm asking because, yes I have a DPMS AP4 (I got it with the sale of a bolt gun) and I wanted to get a spare BCG and was looking at LMT's BCG. But I don't want to spend the money if it wouldn't work. I already did the extractor and buffer upgrades.
The LMT BCG will drop right in.
Years ago, tolerances on things like uppers and lowers were an issue, but are much less of a problem these days.
Thanks for the reply. I haven't had any issues with this gun so far, as I did take the time to take care of some "minor" things that have been mentioned on this forum. I just want to make this gun a little bit better, as trying to buy a Tier 1 type gun really isn't an option right now.