“Over twisting” a problem?

[Shane Lindsey]

Greetings all,

I have an 8 twist 300 RUM.

Will shooting 215 Bergers be an issue down range? I have heard yes and no so wanted experience from those that have shot similar. Just in the initial stages of development and they have good potential, but don't want to burn up components if they aren't going to work at longer ranges. I have looked at the Berger calculator and they are at 2.32, hence this post.

245s seem to be a little tougher to find a load, but getting there.

Thanks.

 

[SShultz]

My 8 twist 300 PRC seems to prefer the 212s over the 225s. Just factory ammo for now. Just goes to show that every rifle is different I guess.

 

[Franko21]

The overspin formula that I have seen used is below. Supposedly above 300K RPM and you become more likely to blow up bullets. This will also be influenced by the state of the barrel (e.g., an older rougher barrel will blow them up at lower RPM).

(MV*720)/BTR = RPM

MV = muzzle velocity

BTR = barrel twist rate

 

[Canadian Bushman]

More than likely no.

You may get slightly larger groups than you may of with a slower twist but this is arguable, and depends on bullets balance and bullet/case straightness.

You will also have to deal with a bit more spin drift. Ballistic calculator will do this.

On the plus side, higher stability has been shown to aid in the performance of bullets traveling back down to subsonic speeds.

If i shot a rum i would definitely shoot an 8 twist despite these very minor issues. With that amount of powder i would want to be able to shoot the 230, 240, and 250 class 30's.

 

[Shane Lindsey]

Thanks,

If these don't work out, there is always THE easiest loading bullets, Hammer to try out. Have some 181s loaded up to test.

Waiting to see how these 215/245s shake out

 

[Canadian Bushman]

Thanks,

If these don't work out, there is always THE easiest loading bullets, Hammer to try out. Have some 181s loaded up to test.

Waiting to see how these 215/245s shake out

Is that so?

 

[Shane Lindsey]

Yes, multiple cartridges and calibers. Very forgiving, easy to make shoot well.

 

[Canadian Bushman]

Why bother shooting anything else

 

[Shane Lindsey]

If i shot a rum i would definitely shoot an 8 twist despite these very minor issues. With that amount of powder i would want to be able to shoot the 230, 240, and 250 class 30's.

Probably for the same reason you would...BC/Wind

 

[Canadian Bushman]

Two very good reasons not to shoot hammers.