NOSLER

444marlin · Mar 16, 2005

Are there any plans in the near or distant future for a 120gr .257" ballistic tip? I know there are 115's (silvertip and BT) but I was just wonderin if there will ever be any 120gr BT's made.

Guest · Mar 16, 2005

Due to the length of the Ballistic Tip design, a 120 is to long to stablize in standard twist rates. Likewise the 110 AccuBond is the longest that will stablize.

444marlin · Mar 16, 2005

I thought the longer the bullet the easier it was to stabilize? I guess I was wrong.

Anonymous · Mar 18, 2005

Our ballistics guru made a good analogy for me on this topic. Remember the wooden tops we used to play with as kids. Spin them with our fingers and they stabilize on the point of the top. Now think of trying to do the same with a pencil. Not a real scientific example but I think it's a good comparison. I hope that helps.

huntingmandan · Mar 18, 2005

One other thing I think they mean by "Stabilize" has to do with twist rate. As that bullet screms downt he barrel, twisting away, the bullet takes on a "rotaional velocity". Each weight projectile, takes on a different rate of rotational velocity, depending on amount of contact surface of the bullet and it's weight. That's why you'll see some boxes of long, heavy target bullets lableled for "1 in 8 twist barrels only" it needs a faster twist to give that long target bullet enough twist to be stable in flight. Much like a quarterback throws a spiral. If it doesn't spiral fast enough (rotational velocity) it wobbles!!! If you made a lead football, or just a heavy one, it would take more rotational velocity to be stable in flight!

Does this make sense, or am I off my rocker?

physicsmandan

444marlin · Mar 18, 2005

Nosler's explanation is easier to understand

aceoky · Mar 18, 2005

This may(or may not help), since a bullet has to be a certain diameter(caliber), the only way to make it weigh more(of the same material) is to make it longer, thus longer=heavier. I hope that makes sense!

Tailgunner · Mar 19, 2005

Hunting man Dan
Your close, it's not the weight (dispite what all the charts say) that determines the twist rate but the length. A 257 100gr wadcutter or RN design will stabilize at a lower rotational velocity than a 257 100gr VLD design (the pencil analogy). Refer back to the Greenhill formulia for twist rate, and you will see that everything is baised on length (not weight), and the longer the bullet, in the same diameter, the faster it needs to spin.[/u]