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Posted: 1/19/2009 9:48:28 AM EDT
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Took a newly built 9mm AR to the range today. It has a RRA BCG, FCG (9mm hammer used) and barrel, a Hahn permanently installed mag block and I was using 20 and 32 rd C-Products mags. Ammo was Remington UMC.
It would consistently jam each round at a 45 degree angle when trying to load a new round, it would so this with such force that the bullet would actually be pushed back in the brass. When looking at how it was cycling it appeared that the BCG was barely moving back far enough to eject the old round and was closing before the new round could be fully stripped from the magazine. This was with a Spikes dedicated 9mm buffer and a Wolff buffer spring, just for the heck of it I tossed in a regular carbine buffer and spring – it functioned 100% with them. I then swapped in the Spikes buffer and the regular spring, back to jamming the rounds. Finally I tried the regular buffer and the Wolff spring and it runs 100%. Now I have to ask, why would it not run with the dedicated 9mm buffer, could it be too heavy? Also will it damage anything if I run the regular buffer and spring, do I need a buffer spacer? |
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Maybe your bolt is dragging against the mag's right feed lip.
http://archive.ar15.com/forums/topic.html?b=3&f=15&t=387562 |
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The Remington UMC is not powerful enough to cycle the 9mm bolt reliably. The 9mm bolt is a heavy mass to move.
I run a standard RRA 9mm buffer and stock spring in mine and the only feed problem I ever had was with UMC. It even feels wimpy when shooting it. I run WWB 115gr and Remington 115 JHP from WallyWorld with no problems at all. Since your feeding OK with the lighter buffer your C-Products mags are OK. The regular buffer and spring are OK, but I made a nylon spacer for mine to reduce the distance it slams into the bolt catch after the last round. You can use quarters behind the spring to make a spacer as well. If I recall it's about $1.75 worth. Just push it back with $1.75 in there and see how close the bolt face is to the catch. You want about 1/8". |
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Quoted:
What is wrong with C-products mags? Some people have luck with them, some don't. I tried them with basically the same setup as yours. I had Cmags, hahn dedicated block and had multiple malfunctions per mag, I got some older Colt/metalform mags and the problems went away. Now my 9mm runs 100%. The UMC ammo is under powered compared to winchester and will not always cycle the bolt as it should. There have been many threads on the Cproduct mags, try a search and check them out. |
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Quoted:
The Remington UMC is not powerful enough to cycle the 9mm bolt reliably. The 9mm bolt is a heavy mass to move. I run a standard RRA 9mm buffer and stock spring in mine and the only feed problem I ever had was with UMC. It even feels wimpy when shooting it. I run WWB 115gr and Remington 115 JHP from WallyWorld with no problems at all. Since your feeding OK with the lighter buffer your C-Products mags are OK. The regular buffer and spring are OK, but I made a nylon spacer for mine to reduce the distance it slams into the bolt catch after the last round. You can use quarters behind the spring to make a spacer as well. If I recall it's about $1.75 worth. Just push it back with $1.75 in there and see how close the bolt face is to the catch. You want about 1/8". Mine eats UMC, WWB, and anything else I run throug it with no problems and I use the Slash 9Q Heavy Buffer with Wolff xtra power spring and C-Prod Mags. The problems has to be something else............ |
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I am leaning towards the ammo since my 92FS had a similar problem at the range yesterday. Rounds did were not ejecting with enough force to clear the slide and were getting caught. I fired a few mags through it and was getting about 3-4 FTE from each mag. I did not even connect the two since one was on the carbine and the other on the pistol, the ONLY thing in common was the ammo.
The weird thing was it cycled in the other handguns I took, a 5904 and a 226. |
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Quoted:
I am leaning towards the ammo since my 92FS had a similar problem at the range yesterday. Rounds did were not ejecting with enough force to clear the slide and were getting caught. I fired a few mags through it and was getting about 3-4 FTE from each mag. I did not even connect the two since one was on the carbine and the other on the pistol, the ONLY thing in common was the ammo. The weird thing was it cycled in the other handguns I took, a 5904 and a 226. Your 5904 and a 226 have weaker recoil springs thats why they cycle fine with that weak ammo. |
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