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Posted: 12/13/2008 9:02:12 PM EDT
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I just finished up an assembly of a pile of spares into an A2 configuration rifle, and tested it today with some '89 vintage Radway Green. The rifle is a complete mutt: old Eagle Arms gray upper with new Bushmaster govt. profile 1/9 20-inch barrel, used Colt bolt with unissued J-marked carrier, new key with screws torqued to 40 inch-pounds and "field" staked in three places each screw as per the TM, Essential Arms lower with DPMS and Bushmaster small bits, etc., etc. While the rifle was very accurate to 200 meters (sighted using the IBZ), I never got consistent, reliable operation. As per the TM, I expected to have to hand-cycle the rifle for about the first 8 or 10 rounds, but the best I ever got was about 40% semiauto function, even after shooting a total of 120 rounds. After disassembly and cleaning, everything looked okay.
This lot of ammo has given me trouble before in a couple of other rifles, and I wonder if it may be somewhat underpowered; after all it's surplus for some reason or other. I've got some pretty hot Portuguese ammo that I may try to see if it has the gas pressure to create a proper seal between the carrier and key. Oh yeah, I did check the headspace with Go and No-go guages prior to firing. Any thoughts or suggestions? |
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Quoted:
This lot of ammo has given me trouble before in a couple of other rifles, and I wonder if it may be somewhat underpowered; after all it's surplus for some reason or other. I've got some pretty hot Portuguese ammo that I may try to see if it has the gas pressure to create a proper seal between the carrier and key. Any thoughts or suggestions? If you have had issues in the past with this ammo, I wouldn’t sweat the cycling problems your experiencing now. Take the rifle out for round two, see how she functions with some good ammo. |
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Well, a second test run today with a variety of ammo and a comparison carbine (CMMG mid-length upper). I figured I'd follow the suggestions posted. The results were:
FNM AMMO New mutt rifle: 100% function Carbine: 100% function FEDERAL XM193 New mutt rifle: 100% function Carbine: 100% function WOLF 62 GR., OLD LOT New mutt rifle: Short stroking Carbine: 100% function ULTRAMAX 55 GR. RELOADS New mutt rifle: 100% function Carbine: 100% function WOLF 55 GR., VERY RECENT LOT New mutt rifle: 100% function, but failure of the bolt catch to engage after the last round; only one magazine fired Carbine: 100% function Thanks for the feedback, guys-looks like the mutt is a keeper! |
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