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Posted: 9/8/2002 11:02:14 AM EDT
i have been shooting action and three gun with a bushmaster 1/9 post carbine. 55gr fed.american eagle fmj., and pmc 55gr. fmj.bt.[great stuff]. my colt carbine says 1/7 twist and its still unfired. what ammo do i use in this one? ive read so much info about this im still having trouble. thanks.
Link Posted: 9/8/2002 12:16:20 PM EDT
The Milspec 1 in 7 turn is for the heavier M855 (Green tipped Steel penetrator - 62 grain) and M856 (tracer round).

For gerenral plinking, you can still use the 55 grained ammo, but for competition, you may want to find the heavier round.
Link Posted: 9/8/2002 12:29:48 PM EDT
DOES THIS MEAN THE 55GR. WILL BE LESS ACCURATE IN THE 1/7 THAN IT HAS BEEN IN MY 1/9? MOST OF MY SHOOTING IS 50-100 YARDS. SOME TARGETS THOUGH CAN BE A BIT CLOSE AND 'POINT BLANK'. AM I CONCERNED ABOUT NOTHING, IS THIS ACADEMIC IN MY CASE OR DO I NEED TO STICK WITH A 1/9. SEEMS A LOT OF RIFLES ARE WEARING 1/7 THESE DAYS. IF I STICK WITH THE 55'S IN MY NEW 1/7, WILL I NOTICE ANY CHANGE?
Link Posted: 9/8/2002 5:18:09 PM EDT
Link Posted: 9/9/2002 5:33:01 PM EDT
Hey Troy I am confused. I have a 24" SS bull barrel with a 1/8 twist. Everything I read (the ammo facts) leads me to believe that a lighter bullet will fly good to about 80 or so but I would get lucky to hit paper at 100 yards. That seemed to be true when I shot my rifle for the first time several weeks ago. At 50 I had touching holes, at 100 the holes were all over the place (55 gr Wolf). I figured it was just crud ammo. Sun. I shot 77 gr match Hornady with the best group at approx 5-inches, the 62 gr American Eagle best group was approx 7-inch and the Win Power point 64 gr about 4-inches (scoped rifle). What gives? Will a 55 gr overstabilize? Spin apart? I shot my sons Savage 110 youth (.223) and had a 3-shot group of 1-inch @ 100. I am at a loss. I called the place where I purchased my kit and they are going to check it out for me.

My questions are: What weight bullet is best suited for a 1/8 twist? I want to hunt with the rifle (wild pigs and head shots). Is this a common problem?
Link Posted: 9/9/2002 8:46:11 PM EDT
Q2,
That Wolf crap notwithstanding, your 1/8 barrel should shoot any of the others that you mentioned without a hiccup.
Not being there and looking at it personally, I'd have to SWAG it and say that it's your rifle that's at fault.
Link Posted: 9/10/2002 8:57:25 AM EDT
[Last Edit: 9/10/2002 8:58:24 AM EDT by mr_wilson]
Q2 - you mentioned (scoped rifle) before I'd blame the rifle I'd take a hard look at the scope and the mounts.

You didn't say what brand of rifle, and hinted that your rifle was a kit, but a your results indicate a sever accuracy diffraculty in your group sizes.

Is this scope mounted on an A2/A1 carry handle (and consequently sits high)?

Are you getting these size groups from "offhand" or is the rifle benchrested?

A 24" 1/8 twist rifle should place most if not all of the rounds, (even the Wolf) at near 1 MOA at 100 yards. The 77 grn Hornady should in general be between 1 and 0.5 MOA as it's pretty decent ammo, so your on the right tack here, somethin' sounds fishy. I'd review my optic and mounts as those groups are large even compared to my 14.5" w/ AK Bushy using an Aimpoint ML2 at that range, and no way should that be.

Mike
Link Posted: 9/10/2002 11:35:22 AM EDT
Link Posted: 9/11/2002 3:45:27 PM EDT
Thanks! I will give the specifics, I was shooting from a bench rest, my lower is a DMPS from a LoPro Classic, the kit is from J & T (flat top), the scope mount is a one piece (base and rings)from RRA (or Model 1), the scope (I admit not the greatest) is a Tasco 4-18 X 44 AO Varmint. Like I said nothing grouped. I contacted J & T Distributing and they asked me to return it. So far I am please with their customer service and response to my questions and seem genuine in their attempt to help me.

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