Good artical on twist rate

Freezer

I read a good artical on twist rate on Shooting times. Though it focased on the .223 it was aplicable to other cartridges. Well worth a look.

41magnut

I Agree.

I do not remember if the article used the 80 grain projectile.

I do not know of anyone using the 90 grain bullet in HP due to the fast twist rate required, but many use the 77 to 82 grain bullets.

Probably not enough difference between the 80 and 90 grain bullets to be worth the time/expense.

Nice work and informative read.

Pegasus

I read the article and I actually thought that while Metcalf did a commendable job writing up his findings the whole premise was not worth the paper it was printed on. Metcalf did allude to the problem in the study but he plowed on regardless. I guess when you have to write an article, you do so by whatever means.

The big problem is of course that he used a veritable smorgasbordof rifles with disparate twist rates, barrel length, contours and quality.

In F-class, I know of a few people who use the 90gr JLK (not Sierra,) and the do well when the conditions are favorable. We are talking twist rates between 6.5 and 7 but with long barrels and hot loads. Also, shooting at 100 yards is not the best for the very long bullets and long barrels. It has been postulated by many that these long bullets require a bit of time to "go to sleep," and time is distance. I would not bother with the 90gr bullet at distances less than 5-600 yards. I also noticed that he used no 80gr bullet, which is by far the most popular bullet weight for the high power shooters beyond 200 yards. I used them from 300 to 1000 yards and they have done well for me.

I do know of a couple of people shooting the 90gr in Service Rifle, but these people border on the insane in my book, though they do well.