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+--- Thread: AA magazines (/showthread.php?tid=438)
AA magazines - turnbull - 05-08-2011
I ordered 3x 25rd magazines from Alexander Arms, and none of them would feed rounds into the chamber. I ended up bending the feed lips on all 3, and as far as I can tell, they work fine now. But has anyone else had this problem with AA magazines?
BTW I was using Wolf 120gr hollow point ammo
AA magazines - khamill2000 - 05-09-2011
I just ordered 3 on Friday. I sure hope they work
AA magazines - turnbull - 05-09-2011
Well it could also be my gun. I bought a custom made upper, and the guy said it was made from a standard .223 upper.
AA magazines - fanofflyn - 05-09-2011
I had the same problem with the Wolf 120gr WPT catching on the feed lip to the barrel, only on the right side, and bending the lip on the mag slightly appears to have fixed that problem. I was using a CP mag. I was using a MGI upper, which will be replaced with a different one when it arrives.
AA magazines - turnbull - 05-09-2011
Nevermind it wasn't the guns fault because I remember looking at the loaded magazine and noticing that the cartridges did not line up properly. I also noticed that the feed lips were at different angles. So that means either there was a problem with the magazines or a problem with the ammo. I know that Wolf ammo is significantly different; I hear the brass is formed from 7.62x39 brass, it uses a large rifle primer instead of small rifle, and the flash hole is slightly larger. Or maybe I just got a bad batch of magazines.
AA magazines - warped - 05-09-2011
I don't know that it is actually formed from 7.62 brass, if it were it would be capable of holding even less powder than it does.
AA magazines - RangerRick - 05-10-2011
It might be the upper. Does it have M4 feed ramps? If you aren't sure what to look for check here: http://upload.bayoushooter.com/images/rsd7g26ytlrn3q8z9uev.jpg
You can do this yourself with a dremel tool if you are careful, the aluminum in the upper is soft compared to the barrel extension.
AA magazines - turnbull - 05-10-2011
RangerRick Wrote:It might be the upper. Does it have M4 feed ramps? If you aren't sure what to look for check here: http://upload.bayoushooter.com/images/rsd7g26ytlrn3q8z9uev.jpg
That link appears to be broken.
I have already ruled out the upper because before I bent my feed lips to where they are now, the cartridges were not lining up properly in the magazine. But like I said, they seem to work fine now.
AA magazines - RangerRick - 05-12-2011
turnbull Wrote:That link appears to be broken.
I have already ruled out the upper because before I bent my feed lips to where they are now, the cartridges were not lining up properly in the magazine. But like I said, they seem to work fine now.
Sorry about that. You can google "m4 feed ramps" and see beaucoup pics if you are interested. Glad you got the problem solved.
AA magazines - fanofflyn - 05-13-2011
OK, got it. It's standard feed ramps with M4 cuts in the upper receiver, leaving a lip that the feeding round can catch on the end. The magazine change fixed it for now, but my upper receiver change to the next one when it arrives will be a permanent fix. If it has M4 ramps cut in the receiver too, I'll modify the barrel feed ramps before bolting it in.
--fanofflyn
AA magazines - turnbull - 05-20-2011
fanofflyn Wrote:OK, got it. It's standard feed ramps with M4 cuts in the upper receiver, leaving a lip that the feeding round can catch on the end. The magazine change fixed it for now, but my upper receiver change to the next one when it arrives will be a permanent fix. If it has M4 ramps cut in the receiver too, I'll modify the barrel feed ramps before bolting it in.
--fanofflyn
I just checked out my upper and thats exactly whats wrong with mine. How do i fix that?
AA magazines - pinzgauer - 05-20-2011
turnbull Wrote:I just checked out my upper and thats exactly whats wrong with mine. How do i fix that?
While many say to Dremel M4 ramps, thats only recommended if it's the barrel ramps that need to be fixed. And you can ruin the barrel very easily. If it's the upper receiver that's not M4, you are cutting through the hardened surface on the upper receiver when dremeling. You really need to use a proper M4 receiver.
Personally, I'd swap the barrel or upper receiver as needed. New upper receiver is not much, and your old one will have some resale value. 15 minutes to swap for someone who has the tools and know how.
AA magazines - LRRPF52 - 05-20-2011
turnbull,
You need a barrel extension with M4 feed ramps, or a standard upper. A standard barrel extension without M4 feed ramps with an M4 upper is a recipe for a jam-o-matic. BCM has standard uppers available with a flat top like the M4.
http://www.bravocompanyusa.com/Upper-Receiver-Flat-Top-Stripped-p/flat%20top%20upper1%20strip.htm
Les Baer and LaRue use standard barrel extensions after conducting high-speed camera testing and seeing that standard ramps work more reliably, according to their results.
The M4 feed ramps are really meant for full-auto M4's where the cyclic rate is much higher than the M16 since the gas system length is so much shorter. Basically, the M4 feed ramps were a band-aid that was applied to a problem encountered when high cyclic rates started stripping the next round out of the mag earlier than in semi-auto. Most current makers that consider themselves with the times use M4 feed ramps thinking they must be better since the military is doing it.
LRRPF52
AA magazines - pinzgauer - 05-20-2011
+1 pm LRRPF52's comments.
I've got one Grendel with std feed ramps, and across about ten cprod mags, reloads, wolf, hornady, never have see a feeding problem. So the std ramp upper is a viable option.
Whoever built your rifle should never have mismatched them.