I don’t know if this is magazine, ammo related or something else. I have only put approx 100 rds through it. This is a used Bushmaster 20" heavy barrel upper and E.A. lower that came with 3 used metal mags. The day I bought the gun (about a month ago) I loaded the first mag with 30rds of American Eagle XM193 and blew right threw them and that was all the shooting I did that day. The next time I took the gun out I had one mag with PMC bronze and another with Lellier&Bellot (one of these mags was the same one that I had shot the American Eagle but I don’t know which one) Well anyway I blew right threw 1 mag and the other mag would not feed. ( I had to charge it for every shot) After that I stripped all three mags and cleaned and lightly oiled them. I took my AR to the range today and well same problem. I had one mag full of Lellier&Bellot and I had to charge it every time, so about 5 rds into it I unloaded the mag and refilled it with 4 rds of American Eagle and 6 rds of Fiocchi (because all the other ammo i had was the L&B) 1 of the 6 Fiocchi did not feed and all 4 of the American Eagle rds fed. Is L&B ammo crap? Or do you think I have a mag problem? I am very inexperienced with the AR more used to AK’s as I have owned 2 and never once had 1 failure with either of them it didn’t matter what kind of crap ammo I used. I love the way the AR handles but the reliability factor so far has got me scared.
You need to start isolating certain variables because otherwise you are on an Easter egg hunt.
Mark you mags, so you can tell them from one another. Take them out again, determine which is causing the problems and throw it away. Better yet, just order some PMags, and be done with it. Also, make sure that Bushmaster gas key is nice and tight.
Numbering the mags is a good start. Obtaining another control mag is also good. But it may not be the mags. You need to isolate variables in a logical fashion.
Checking the key is a good idea as well, and it is a good one to check first.
Using one type of ammunition in one magazine and then trying different ammo in the same magazine will help whittle down variables.
camoman, is it possible to take some pictures of your rifle and magazines?
I took some pictures of the gas key, the mags, and the inside of the upper. 2 of the mags are Kay industries and 1 is a Colt. Today the problem mag was the colt. I have already marked them all. What do you look for with the gas key? I don’t know what to look for.
Looks like your gas key isn’t properly staked but unless it’s really loose I would think your feeding issues are more likely to be related to your mags.
Here is more pics, sorry about the quality its a cell phone.
Pick up a p-mag and give it a try.
and try to keep just to one brand of ammo just for now.
The pics are too low resolution to tell much. It almost looks like your key has been staked with a punch and counter-staked… do the screws seem tight with metal pushing in to prevent them from rotating?
It sounds like it does not like the S&B ammo nor the Fiocchi - not highly surprising. It sounds like it does like the AE ammo… again not surprising.
Look at your buffer and tell me if there is a letter on it - H, H2 or H3 or no letter at all.
When you said before “won’t feed” do you mean every issue involves not stripping a round off the magazines and feeding it… or are there any other malfunctions occurring?
I know it’s hard to tell from the picture it looks to me like a 5 year old or a very drunk person staked my gas key with a very unsteady hand. It looks extremely unprofessionally done compared to the picture you showed me although it is tight and I don’t think it could move
Is it ejecting the spent brass properly?
The buffer has no letter. When I say not feeding I mean the most the rounds do not leave the mag yet the bolt-carrier locks up and “click” ( some brass has a nice big scrape some don’t) then I charge it and shoot 1 rnd and then “click” and some that do leave the mag get caught on the feed ramp, but then every AE rnd has gone boom so far. I think I will get some more American Eagle (enough to fill all mags) I am going to get to the bottom of this one way or another. If I still can’t find the problem I’ll take it back where I bought it and have them fix it hopefully for free since I have only owned it 1 month.
No problems ejecting at all.
Just a very quick assessment sounds like short stroking on the weaker ammo. This could be for several reasons. I would suggest picking one mag and running it with the AE for function. Then try another mag with AE for function. Then your third with AE.
Report results.
closed on empty is a magazine problem, most of the time, and the rest of the time it’s gonna be short stroking or hyper-action related to over-sized gas ports and under-weighted buffers or worn or bad buffer spring.
measure your buffer spring… if it’s shorter than 10.5" or so, i’d replace it. if this weapon is a 16" barrel with carbine-length gas (FSB/gas block is ~7" from the bolt), then you should upgrade to an H or possibly H2 buffer.
load one round, fire… does it lock back? and get at least one known-good magazine
I am personally leaning towards a mag/ammo problem or both. I called the guy that sold the gun after the first malfunction and he told me he would replace the mags if bad, after seeing all the crap that came out of those mags when I cleaned them I was sure the problem was solved. Let me ask you if I determine all the mags are good, and the gas key is good what is left?
If the mags are good and the gun runs 100% on AE ammo then it could just be that your gun likes to run with hotter ammo. I have a 12.5" 5.56mm AK like that. It’s pretty much just a small gas port in my case. Generally Bushys have large gas ports but anything can happen.
then see my last post… if it’s short stroking, it wont lock back on an empty mag. if it wont lock back, might be a bad buffer spring.
if it’s hyper cycling, could be the gas port is a bit oversized… worn buffer spring along with a carbine buffer can be the cause… replace the spring if it’s shorter than 10.5, and upgrade to an h or h2…
as far as weak ammo… dunno… unless it’s a defective batch, your weapon should still cycle it.
You can have mag issues with brand new mags I have an uber HK:rolleyes: mag that can not lock the bolt back on the last round.
P-mag is probably the most reliable mag on the market right now.
One other thing what is your buffer spring length the recommended length is 10 1/16’’