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Posted: 12/18/2005 7:47:38 PM EDT
Anyone ever shoot 40 gr. and 55 gr. out of their 1-7?....I havent had any issues out to 50 yards witht the 55(anyone shoot em farther?) but havent tried the 40gr.
Link Posted: 12/18/2005 8:19:36 PM EDT
55 in a 1/7 no problem, never tried 40. Have you read the Ammo Oracle?
Link Posted: 12/19/2005 4:39:33 AM EDT
+1 on the ammo oracle being a guideline.



i myself have found 55gr. ammo to have fair accuracy in my recon 1x7 at 100yds. nothing to brag about but then pretty impressive for regular 55gr.
Link Posted: 12/19/2005 4:43:51 AM EDT
IIRC, brouhaha has fired 40grn. ammo outta of his 1/7 twist rifles, myself the lightest I have shot out of my 1/7 twist M4s is the Walmart Value Box 45grn. Winchester HPs.

They shoot just fine.

Mike
Link Posted: 12/19/2005 6:51:23 AM EDT
Fired 40 gr Fed Blitz and 40 gr Hornady VX out of two different 1:7 barrels with no problems out to about 100 yards.
Link Posted: 12/19/2005 6:56:38 AM EDT
M193 (55 gn) shoots better than M855 (62 gn) out of a 1-7 in my experience. You can overstabilize a bullet and it will still shoot well.
Link Posted: 12/19/2005 7:15:31 AM EDT
55 gr doesnt seem to be a problem, I have had some issues on 52 gr HP past 100 yards, but 50gr ballistic tips seem to work fine, though I haven't taken them past 150 yds yet. I have not tried 40gr in it at all.
Link Posted: 12/19/2005 8:55:41 AM EDT
I think jacket construction becomes more of a factor with faster twists. Some of the "varmint" bullets may not hold up so well to a faster twist such as a 1-7. I have shot 55 grain M193 out of a M-16A2 at 600 yards on a KD range as an experiment and it shot surprisingly well. I remember shooting a highpower match and a new guy tried shooting some light bullet factory ammo and none of his bullets made it to the 600 yard target. While watching his trace through my spotting scope I noticed his bullets seemed to come apart at around 300 to 400 yards at the apex of the trajectory. I gave him some good stuff to finish the match with when I discovered what was happening. I have watched other caliber bullet blow up on their way to the taget and oddly enough they all blew up well down range instead of right out of the muzzle. Anyway I'm long winded. You can shoot light bullets in a fast twist without problems as long as the bullets are not lightly constructed.
Link Posted: 12/20/2005 7:35:23 AM EDT
I've shot 40 and 45g out of my 1/7 and haven't experienced any real issues. At 55', the rounds all impact in a 2" group. Longer than that, my eyes don't do too well and accuracy suffers. With a scope, I can make hits out to 100yds.

The 45g, iinm, is sold as a varminting round and should be durable enough to handle a fast twist. My biggest concern is cross-winds.
Link Posted: 12/20/2005 9:37:41 AM EDT
I get 0.3 MOA 5-shot groups at 100 yards with 40gr VMAX bullets out of a WOA CMP 1:7 barrel.
Link Posted: 12/20/2005 5:03:21 PM EDT

Originally Posted By BradH:
I think jacket construction becomes more of a factor with faster twists. Some of the "varmint" bullets may not hold up so well to a faster twist such as a 1-7. I have shot 55 grain M193 out of a M-16A2 at 600 yards on a KD range as an experiment and it shot surprisingly well. I remember shooting a highpower match and a new guy tried shooting some light bullet factory ammo and none of his bullets made it to the 600 yard target. While watching his trace through my spotting scope I noticed his bullets seemed to come apart at around 300 to 400 yards at the apex of the trajectory. I gave him some good stuff to finish the match with when I discovered what was happening. I have watched other caliber bullet blow up on their way to the taget and oddly enough they all blew up well down range instead of right out of the muzzle. Anyway I'm long winded. You can shoot light bullets in a fast twist without problems as long as the bullets are not lightly constructed.



I have had personal experience with light varment bullets disintegrating in flight when fired out of a 1 in 7 twist ruger. To keep them in one piece you need to down load them quite a bit.

Link Posted: 12/21/2005 2:25:46 PM EDT
At least no one has said "overstabilized" yet
Link Posted: 12/22/2005 10:09:15 AM EDT

Originally Posted By BradH:
M193 (55 gn) shoots better than M855 (62 gn) out of a 1-7 in my experience. You can overstabilize a bullet and it will still shoot well.



He did.
Link Posted: 12/22/2005 1:11:26 PM EDT
+1 on BradH's explanation. "Varmint" bullets are built so that they disintegrate as soon as they hit anything, (prarie dog, etc.) and to do that reliably they need specific parameters for muzzle velocity and spin rate. They use very thin jackets (sometimes internally pre-scored) and soft lead cores, so they're pretty flimsy to begin with. If you exceed the parameters for velocity, spin or both, you can expect the jacket to rupture, the core to spin like clay on a wheel and the bullet to generally disintegrate anywhere outside the barrel. This is BAD because there's no telling what the bullet's parts are going to do-they won't necessarily disappear in a puff, and may fling jacket parts and lead just about anywhere.

Military bullets, like the 55gr spitzer used in M193 are usually made with sturdy jackets that also encase the whole front of the bullet, wrapping around the base to very firmly hold the bullet together, while varmint bullets tend to have open (sometimes WIDE open) tips or very large soft points. The 45gr Winchester bullets I've seen are fairly robust; they're not going to just vaporize on you in most AR-compatible loads. But I wouldn't push them too far beyond normal AR velocities, either.
Link Posted: 12/23/2005 1:36:58 PM EDT
I have poor luck with the extreme varmint bullets in 22" 1:7 barrels.

I had 3 of 18 Hornady 55g SP SX bullets make it 100 yards. 3 of 15 Sierra Blitz bullets, also 55g made the trip. Velocities varied from 3,050 to 3,250.
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