Top row, left to right: MWG 10 round, Colt post-ban 5 round, Colt pre-ban 5 round.īottom row, left to right: Scherer 30 round, G-Tech 30 round, USA 20 round, USA 30 round. Here is a pic of the various types of 7.62x39 AR15 magazines Boomer has collected over the years: Surprisingly, despite otherwise having a reputation for total crap, USA had some good high cap 7.62.39 AR magazines that used their own AR style steel feed tower spot welded to their proprietary AK style body, spring and follower and they work very well. These are aftermarket steel AR towers TIG welded to genuine AK47 magazine bodies with similarly genuine AK47 springs and followers. Scherer and Gordon Technologies magazines are the most robust of the preban high capacity magazines. While there were some stamped sheet metal magazines from companies such as Triple-K, Western, USA, etc, the only ones worth a darn were what are essentially hybrid magazines AR15 style feed towers welded or riveted to AK47 style bodies. After the ban they switched to a cut down USGI style magazine feed tower with a unique composite base to prevent them from being converted back into 20 round magazines in violation of the AW ban at the time.īecause the 7.62x39 AR15 appeared relatively shortly before the AW ban and never really gained much popularity in that time, development of high capacity magazines for it was limited. These internal blocks were easily removed after which the magazine would function just like any other USGI 20 round magazine. After that, the cartridges begin to bind up and jam.Ĭolt first used regular USGI 20 round magazines with internal blocks to limit capacity to 5 rounds of 7.62x39. Pretty much any USGI 5.56 magazine will work reliability with 5-6 rounds of 7.62x39. Magazine have always been the Achilles heel of the 7.62x39 AR-15. I used the same small diameter stone to round the top edge of the feed ramps and then polished them for smoother feeding. I also noticed that the sharp top edge of each ramp would put grooves in the round as it was chambered. I would highly suggest that you use some rubbing compound and polish the feed ramps. I used a small diameter stone to blend the steel barrel extension to the aluminum upper extended feed ramp. I have done the same modification that you have pictured to my three 7.62X39 uppers, which has greatly improved feeding reliability.

Since the center line of the 7.62 round is lower, there would need to be a deeper ramp because the round starts further from the center line of the bore. The 7.62X39, having a larger diameter, will have its center line lower, compared to the center line of the bore. So the top of either round is up against the top lips of the magazine. The 7.62X39 round is larger in diameter than 5.56X45. With an unaltered carrier whatever magazine is installed is limited in height by the bottom of the carrier. The manufacturer used a hammer, too, which explained why they looked a little beat up before we took the gun apart.Some geometry to think about. We had to use a hammer to get the KNS pins back in the gun. Looking at the course hand filing does not inspire confidence. So you end up with an inch and half gap between the handguard and the gas block. They do have a custom length gas system (they say it's a piston) for the 338 but didn't have the funds to have custom handguards made to match the length. For your $6,000, you get a DPMS parts kit with the worst trigger pull I've ever felt (presumably because the hole position is not quite correct). Inside the receiver you'll find bad milling work done after anodizing and the aluminum left bare. The magazines are garage-press bent to shape and then some amateur welder finishes them. The holes were drilled after anodizing and were so out of spec the manufacture had to hand file them a bit to get the upper and lower together. The fit is so bad we had to hammer out the KNS pins holding it together. I liken it to a garage built gun by someone who just got a mill.

338 spectre upper for are15