Twist rate and bullet weight in 375 and 38-55

[andym79]

Just a curiosity, why do some reloading manuals list up to 335 grain projectiles for the 38-55 when it has a slower twist rate of 1 in 18; but not for the 375 which has a faster 1 in 12 twist?

Surely the 38-55 would struggle to stabilise the 335 grain projectile, whereas a 1 in 12 twist should easily stabilise it!

The 38-55 should top out at 260 grains due to its slow twist :unsure:

Just a curiosity, why do some reloading manuals list up to 335 grain projectiles for the 38-55 when it has a slower twist rate of 1 in 18; but not for the 375 which has a faster 1 in 12 twist?

Surely the 38-55 would struggle to stabilise the 335 grain projectile, whereas a 1 in 12 twist should easily stabilise it!

The 38-55 should top out at 260 grains due to its slow twist.

Can anyone explain, surely you can you 335 grains in a 375?

[Ironsides]

I think you're right. It seems that Winchester may have gone with the 1 in 12 twist for their .375 simply because that was what H&H had done years before. Maybe if the cartridge had developed a bigger following we would have seen heavier factory loads produced. Or....maybe if they had offered heavy bullets from the outset it may not have all but died. I copied this from another site:

http://castboolits.gunloads.com/showthr ... nting-load
"All original factory 375 Win barrels including Savage, Ruger, Winchester, and Marlin used a 1/12" twist barrel. Kind of silly when you think of the factory bullet weight at 220gn.
Compair to the 38/55 that is vertually the same cartridge used a 1/18" twist for a heavier bullet. Why then did Winchester decide to use a 1/12" twist for the 375 Win?
My guess is because they didnt even consider twist rate and what effect it would have on performance of the cartridge. They just simply went with what had always been used in 375 caliber (not 38 caliber) and kept what H&H decided on in 1912 a 1/12" twist.
The H&H 375 was always intended for 300+gn bullets and so did need a steeper twist to handle those heavier bullets for both internal and external balistics. There was a time when 350gn bullets were readily available for the H&H version of 375.

There is a point I am trying to make with this historical run on and that is that in my own experiance which I would safely put in 1000s of rounds through all the afformentioned types of rifles I have noticed that heavy boolits 300 to 350gn seem to be easier to find good accurate ( less than 2 moa) loads than the more conventional weights (200 to 250gn)."