Technical barrel lenght/ twist rate stuff... I need help.

[Furync]

Hi everyone,

I've been looking into buying an all purpose bolt rifle in .308 and it's offered in a bunch of different barrel lenghts and twist... Now, I'm no expert on this stuff...

The reason I'm buying the rifle is basically for hunting big game at any range, hunting varmints, and long range plinking (200-400 yrds). So I will need variants in bullet weights obviously and this is where I'm lost.

The guns I'm looking at have these specific barrel lenghts/twist:

24"/10"
26"/12"
22"/10"
22,7/16" /11"

Now here's my question, how do they differentiate when using a variety of bullet weights? will they perform basically the same or will one be better with lighter or heavier bullets? Is there such a thing as an "all purpose" barrel?

How important is barrel lenght? or rate of twist for that matter...?


This is really confusing me... I've never gotten down with the nitty gritty of these things.

Thanks a lot for the help!!

PS: side question that has no relation to the above... is it true that a stainless barrel will not be as accurate as a regular steel barrel? (something about the steel beeing harder to machine...)

Thanks again.

 

[tiriaq]

For what you want to do, barrel length/twist will make no difference. Factory rifles have all-purpose barrels. The stainless steel used in rifle barrels machines more easily than chrome-moly. In theory it is easier to produce a premium barrel in stainless. Once again, for what you want the rifle for, it won't make any difference.

 

[guntech]

The longer barrels will give a bit more velocity. Factory barrels are not as accurate as cutom barrels..... most short range Centerfire Benchrest barrels are stainless and are the most accurate barrels in the world.

As far as twists go here is what I copied from Shilen's website:

.308
- 8" for bullets heavier than 220gr.
- 10" for bullets up to 220gr.
- 12" for bullets up to 170gr.
- 14"* for bullets up to 168gr.
- 15"* for bullets up to 150gr.

 

[Sticker]

Hi

I am going to throw a wrench in your gears

an M24 has a twist of 1 in 11.25 and the bullet is 175 grains

If it's a heavy barrel you want, chances are it will be 1 in 12 and that should do all you want it to do. With .308 Win you probably won't be shooting anything heavier than 180 grn anyway.

Sticker

 

[Furync]

The longer barrels will give a bit more velocity. Factory barrels are not as accurate as cutom barrels..... most short range Centerfire Benchrest barrels are stainless and are the most accurate barrels in the world.

As far as twists go here is what I copied from Shilen's website:

.308
- 8" for bullets heavier than 220gr.
- 10" for bullets up to 220gr.
- 12" for bullets up to 170gr.
- 14"* for bullets up to 168gr.
- 15"* for bullets up to 150gr.

is there a range of bullet weights for a barrel's twist? I mean why arent all barrels with 8" twist so we can shoot anything possible? I know there's a logic behind it but I just dont know the specifics of it


Thanks for the replies everyone, I realise it shouldn't make a big difference for my purpose but I like to have everything "optimal"

 

[dan belisle]

It actually depends on the length of the bullet, rather then the weight. It's just that with standard technology bullets (for lack of a better term), you go heavier and longer at the same time. With some of the new monometal bullets (Barnes X comes to mind), you can get long lighter bullets. Certain length bullets stabilise better with certain twists, which is why we don't all just have a 1-7 twist everything. In your 308, a 1-10 or 11 (or even 12) really won't make too much of a differance, although the single most accurate bullet in one of my HB 308's is the Hornady 190 gr BT. Just pick a rifle you like, any of the twists you mentioned will work fine. - dan

 

[guntech]

is there a range of bullet weights for a barrel's twist? I mean why arent all barrels with 8" twist so we can shoot anything possible? I know there's a logic behind it but I just dont know the specifics of it


Thanks for the replies everyone, I realise it shouldn't make a big difference for my purpose but I like to have everything "optimal"

Slight overstabilization is of no consequence but if you spin a bullet considerably more than required, accuracy can suffer.

A quick twist for a long heavy bullet will result in a lighter shorter bullet spinning way to fast - it could possibly blow up on the way to the target.

The throat would also need to match the loaded round... big long bullets require a longer throat than short light bullets.

One twist/throat/rifle can not do everything......