westcliffe01
Veteran Member
A couple of weeks ago I took my DPMS carbine chambered in 7.62x39 to the range for the first time and was very disappointed. The only manufacturer who makes magazines for the rifle had gone out of business (C-Products) and now I think I know why.... The rifle absolutely would not feed ammunition from the 30 round magazines. Not when loaded with 30 rounds, nor 20 nor 10 or even 5 rounds......
So I had a very frustrating afternoon and ended up feeding rounds manually into the breach to sight in the scope that I had fitted, a 1-4x20 Nikon Monarch. I went home, disassembled the magazines to see what was in them and figure out where the problems were. Needless to say, the magazine feed lips, follower, spring orientation all needed work. I also stripped the upper receiver and was amazed by the amount of brass everywhere so set to work getting things to work smoothly there too.
One of the things I discovered is that in order to get a good color match on parkerizing or plain blackening, the manufacturer will typically do some kind of media blast to get all the surfaces to the same finish, that way, there are not different shades in the color when blackened/parked. The problem is that the blasted surface is not very smooth and this has a significant effect on operation. I ended up using fine emery paper and smoothing the finish on the lower surface of the bolt carrier that rides over the hammer and the top round in the mag when on its rearward travel. The guide rails on the bolt carrier were smoothed too, since these are the primary guide surfaces and they are only running in hard anodized aluminum, so rough finish and sharp edges will make for rapid wear.
Starting out, I could not get 2 rounds in succession to feed in the "as purchased" condition. I was able to improve this to the point that I had only 1 misfeed out of 4 magazine loads (120 rounds). I now do not load more than 20 rounds in the magazine, since the design makes a full mag less reliable. I also ordered 2 5 round magazines and had to rework them, but at least the geometry of the feed lips and the top of the mag was fine. The problem was with the follower and operating spring.
This weekend I was able to fit in another range trip and test the new 5 round mags and just generally see how things were working out. I was shooting Yugoslavian surplus, which has been for sale at $184/1120 round case, but just recently there was a 50% increase in the cost of this ammo.
At 100yds, other than 1 flier, I was able to keep 9 rounds inside the 3" circle on the target. The Nikon scope is relatively low power and at 100yds the aiming point is all but obscured by the cross hairs of the scope.
So I had a very frustrating afternoon and ended up feeding rounds manually into the breach to sight in the scope that I had fitted, a 1-4x20 Nikon Monarch. I went home, disassembled the magazines to see what was in them and figure out where the problems were. Needless to say, the magazine feed lips, follower, spring orientation all needed work. I also stripped the upper receiver and was amazed by the amount of brass everywhere so set to work getting things to work smoothly there too.
One of the things I discovered is that in order to get a good color match on parkerizing or plain blackening, the manufacturer will typically do some kind of media blast to get all the surfaces to the same finish, that way, there are not different shades in the color when blackened/parked. The problem is that the blasted surface is not very smooth and this has a significant effect on operation. I ended up using fine emery paper and smoothing the finish on the lower surface of the bolt carrier that rides over the hammer and the top round in the mag when on its rearward travel. The guide rails on the bolt carrier were smoothed too, since these are the primary guide surfaces and they are only running in hard anodized aluminum, so rough finish and sharp edges will make for rapid wear.
Starting out, I could not get 2 rounds in succession to feed in the "as purchased" condition. I was able to improve this to the point that I had only 1 misfeed out of 4 magazine loads (120 rounds). I now do not load more than 20 rounds in the magazine, since the design makes a full mag less reliable. I also ordered 2 5 round magazines and had to rework them, but at least the geometry of the feed lips and the top of the mag was fine. The problem was with the follower and operating spring.
This weekend I was able to fit in another range trip and test the new 5 round mags and just generally see how things were working out. I was shooting Yugoslavian surplus, which has been for sale at $184/1120 round case, but just recently there was a 50% increase in the cost of this ammo.
At 100yds, other than 1 flier, I was able to keep 9 rounds inside the 3" circle on the target. The Nikon scope is relatively low power and at 100yds the aiming point is all but obscured by the cross hairs of the scope.
Go to Brownells and get everthing you need in the way of tools and parts:thumbsup:
