1:7 and lightweight bullets... [Archive] - Glock Talk

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MCKNBRD
01-19-2011, 17:07
OK, I've heard plenty of anecdotal stuff, but does anyone have any good references concerning the 40 and 45gr bullets (lightweight varmint with thin jackets) and them 'splodin from the higher rotational speeds that you get from the 1:7 barrels?

And please, none of the stuff about 'It never happens!'...I've seen what happens when you don't twist them enough; keyholing 62gr bullets at 25yds is pretty impressive...but blowing apart 40gr varmint bullets?

I just want proof...one way or another. I'm looking at getting an M&P with a 1:7 twist barrel, but its going to spend more time on my lap with a coyote call in my hands than knocking down doors, so a 1:9 isn't bad...but its not available on the rifle I want.

TIA, GT braintrust...

Byrdman

K. Foster
01-19-2011, 17:47
My thoughts are if you really want a 1:7 barrel, shoot heavier bullets at coyotes, possibly a 60g V-max. If you really want to get accuracy with light bullets, a 1:9 might be the way to go.

Gunnut 45/454
01-19-2011, 19:06
I seen a video on Youtube! I haven't used anying smaller then 50 SEI's in my 1:7"! No blow ups! I think there was some of the earlier bullets on the market that had very thin jackets that when pushed through 1:7" barrels that did blow up!:supergrin:

cowboy1964
01-19-2011, 22:17
I'd stick with 1:9. You can go up to about 75gr (the Hornady TAP line specifically says that) and you're also safe down to the really light bullets. But if the choice of rifle comes first then that settles that, right?

glock22357
01-20-2011, 18:54
OK, I've heard plenty of anecdotal stuff, but does anyone have any good references concerning the 40 and 45gr bullets (lightweight varmint with thin jackets) and them 'splodin from the higher rotational speeds that you get from the 1:7 barrels?


How would the shooter know what was happening? How would one tell if a bullet was coming apart in mid-air due to excessive rotational forces? I think you're gonna have a time getting any first-hand accounts of this phenomena, I can't imagine any concrete proof without high-speed videography.

In the end I highly doubt that bullets come apart when shot, but it would be very interesting if someone can come up with verifiable proof.

schiffer99
01-20-2011, 21:01
How would the shooter know what was happening? How would one tell if a bullet was coming apart in mid-air due to excessive rotational forces? I think you're gonna have a time getting any first-hand accounts of this phenomena, I can't imagine any concrete proof without high-speed videography.

In the end I highly doubt that bullets come apart when shot, but it would be very interesting if someone can come up with verifiable proof.

Would be easy to tell at the range. If the bullet is staying together you'll get a nice .223 sized hole on the paper. If its not staying together you'll end up with multiple small tears on the paper (almost like a mini shotgun).

glock22357
01-21-2011, 09:29
Would be easy to tell at the range. If the bullet is staying together you'll get a nice .223 sized hole on the paper. If its not staying together you'll end up with multiple small tears on the paper (almost like a mini shotgun).

1. I'm going to go waaaay out on a limb here, and say that no one has, or will provide, concrete proof of this happeneing. In fact I don't believe that a bullet can be torn asunder by rotational forces.

2. If a bullet did come apart from rotational forces during flight, it wouldn't come within a mile of the target.

Zombie Steve
01-21-2011, 12:02
I have no proof... I just haven't spent money / loaded the lighter varmint bullets for a 1:7 as there are warnings in both the Speer 14 and Hornady 7 reloading manuals. That was good enough for me to not buy the lighter bullets.

hagar
01-21-2011, 13:01
I had 50 grain no name hollow point bullets come apart at 25 yards out of my 1 in 8 twist NM AR during an Appleseed event. Did not happen right away, but after about 100 rounds the bullets were coming apart, and in some cases just the front tips of them made it through the target sideways. Fortunately I got my Riflemans badge before it happened..

MCKNBRD
01-21-2011, 15:25
OK, so, basically, one guy has seen the issue in an AR platform; the rest is theory, rumor, or a liability-driven recommendation.

Upon doing about 3 hours of research (couldn't sleep last night), I found that its only a regular issue if the bullet is cranking along at stout .22-250 or .220 Swift velocities AND its a poorly constructed bullet. So, 3800fps & cheap bullets don't work well in 1:9 or faster twists. Makes sense.

I'll have to fiddle around with loads and such, but I'd like to use a varmint grenade or Nosler E-tip, and I'll see what we get from different weights...I figure the E-tip in 50gr will be as long as a 62-65gr lead bullet...gotta do the research, though.

Thanks, ya'll! I'll (hopefully) post some pics after I get the new stick & have a few songdogs to show off...

Byrdman

Brass Nazi
01-22-2011, 12:14
I read the warning in my Speer manual this morning. It warned about using 55gr and below bullets constructed with a thin jacket in the fast twist rifles.

Zombie Steve
01-22-2011, 16:53
Yeah... what do those bullet manufacturers know? :upeyes:

HAIL CAESAR
01-22-2011, 21:43
Well I ain't the youtuber type...But it does happen. I have done it.

1/7 twist and a varmint grenade bullet.

MCKNBRD
01-22-2011, 22:46
Yeah... what do those bullet manufacturers know? :upeyes:

Thanks for the constructive input...I guess no one should use reloads, either, right? Since those gun manufacturers don't recommend them and all...

Reloading is inherently dangerous enough, and I can see the manufacturers making that kind of recommendation to keep their hands clean in case you try it and end up stuck with a box of bullets that you can't use 'cause they fly apart.

I still stand by the idea that it can work; thing is, I don't have the rifle yet and can't shoot it until I do...I just wanted to see if anyone had any real-world, first hand experience.

Anyway, thanks all for the input...looks like its VERY dependent on the jacket construction (knew that) and muzzle velocity (learned that from research) and that a few folks have had it happen to them.

Byrdman

RMTactical
01-22-2011, 22:58
I've never tried anything lighter than 55gr. Guess I need to see how my 45gr varmint rounds do in a couple of my 1/7's.

Zombie Steve
01-23-2011, 00:20
Thanks for the constructive input...I guess no one should use reloads, either, right? Since those gun manufacturers don't recommend them and all...

Reloading is inherently dangerous enough, and I can see the manufacturers making that kind of recommendation to keep their hands clean in case you try it and end up stuck with a box of bullets that you can't use 'cause they fly apart.

I still stand by the idea that it can work; thing is, I don't have the rifle yet and can't shoot it until I do...I just wanted to see if anyone had any real-world, first hand experience.

Anyway, thanks all for the input...looks like its VERY dependent on the jacket construction (knew that) and muzzle velocity (learned that from research) and that a few folks have had it happen to them.

Byrdman

What are you talking about? Gun manufacturers? I'm talking about the folks that make the component bullet for reloading telling you that the bullet they designed to be pretty fragile so it basically explodes in a varmint will come apart if your put it through a tight twist barrel. I think they are trying to keep their hands clean by selling you a different bullet that will work better for a given purpose and have happy customers that buy more of those bullets.

It's your money. Have fun. I hope it works for you. As I said, for my money and time wasted in load development, I'll go with a different bullet.