Twist rate and bullet weight

[nivlac1960]

What is the correlation between twist rate and bullet weight? Is it the faster the twist rate the heavier the bullet or is it the faster the twist rate the lighter the bullet?

[Terry Balding]

The faster twist rate the heavier the bullet.

Go to the the Berger website the show this with their list of bullets.

Terry

[savageboy]

If you do a search, SSS put together a table for most calibers including optimal barrel length

[keeki]

the longer the bullet the faster the twist to stabilize

[Eric in NC]

the longer the bullet the faster the twist to stabilize


+1 - although there are tons of factors in play (including weight), length of the bullet is most important. For example, a 100 grain flat base round nose bullet in .257 would work with a slower twist than a 100 grain VLD boat tail bullet.

So longer bullets need faster twist rates than shorter bullets.

This gets more important to consider if you are trying to use the "lead free" bullets as they are a lot longer for their weight than traditional bullets.

[Armed in Utah]

Its not the bullet weight..........

Its the bullet length........

[gotcha]

nivlac, You can chk. Bergers site for appropriate twist rates for bullet length to get general idea of twist necessary. Chk google for " greenhill formula" You'll find online calculators there to determine what length bullet your twist will stabilize. Faster the twist, heavier (actually longer) the bullet is the rule of thumb. Problem is, you have to buy the bullets in order to measure them ;D Thats why i mentioned the Berger site. It'll give you a general idea of necessary twist for bullets of THEIR length.

[keeki]

velocity also comes into play

[gotcha]

+1 keeki

[68injunhed]

Very handy website with all kinds of other info as well as lengths.

http://www.jbmballistics.com/ballistics/lengths/lengths.shtml