Neck diameter for new .308 barrel?

[thefitter]

What are people using for neck diameter on a new .308 barrel? I'm getting various opinions from .340 to .342

My hand loads and factory ammo are .337 - .338

Currently my fired cases are coming out at .345 I'd like to tighten that up a bit with my new barrel. Thanks

 

[40x]

Re: Neck diameter for new .308 barrel?

What are you using the rifle for Tactical matches or F-class or something different. If you are going to be shooting factory ammo a .340-.342 will work. If you are hand loading and neck turning you can go smaller neck. You should also figure out your free bore. If you are running factory ammo or hand loads. What gr bullet are you shooting.

 

[LoneWolfUSMC]

Re: Neck diameter for new .308 barrel?

I don't see a need to own a tactical rifle that I have to turn necks for.

I just run a factory chamber. It's not the limiting factor on accuracy on my AI and I still have the option of running factory ammo.

I figure the time I could be spending turning necks is better spent practicing on the rifle.

Also, less brass wear is nice, but not at the cost of reliability.

 

[FCS]

Re: Neck diameter for new .308 barrel?

I prefer 0.0015/side clearance as minimum and up to 0.003/side isn't going to hurt you any.

Fed GMM runs 0.339 to 0.340 in which case you'll want to go with a 0.343" neck diameter just to be on the safe side.
Winchester/Black Hills runs 0.335 give or take 0.001"
Lapua typically is 0.339

Depends on what brass you use to load or what factory ammo you plan on running.

If you are planning on a rifle to shoot anything and everything I'd go with a 0.343 just to make sure you don't have a clearance issue.

 

[thefitter]

Re: Neck diameter for new .308 barrel?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cpapa</div><div class="ubbcode-body">What are you using the rifle for Tactical matches or F-class or something different. If you are going to be shooting factory ammo a .340-.342 will work. If you are hand loading and neck turning you can go smaller neck. You should also figure out your free bore. If you are running factory ammo or hand loads. What gr bullet are you shooting.
</div></div>

I'm planning on setting this up primarily for the Berger 185 BT

I will play with neck turning just to see what it is all about but I don't want to always have to do it.