Bushing Size

[19818119]

Gents,

My loaded rounds are measuring 0.338, I'm currently using a 0.334 redding titanium bushing. I've read that 0.002 neck tension is optimal, should I switch to a 0.336 bushing.

This is for a rifle that is currently being built so I can't compare any accuracy difference by changing bushing sizes just yet.

 

[TCA4570]

Re: Bushing Size

Rath,

Are you getting a ring on your bullets by seating them this tight?

What cases are you using?

Four thou is too much for me!

I need to re-expand by .0015-.002.

Hope this helps, or you can to.

TC

 

[shoepop]

Re: Bushing Size

With Lapua brass a .336 yields .003 NT for me.

 

[Victor N TN]

Re: Bushing Size

Try what you have before buying something else. It may work just fine.

 

[19818119]

Re: Bushing Size

No ring on the bullets, Lapua Brass is what I'm using, I think I'll do as victor suggested and see how the rifle slings them as is before experimenting.
Thanks

 

[MitchAlsup]

Re: Bushing Size

A) The amouont of neck tension is application dependent--generally for tactical applications where the cartrige has to put up with a little (but not a lot of) abuse, 0.002 is a fine amount of neck tension.

B) You could turn the necks to allow the 0.334 bushing to perfectly size these cases, as an alternative to a 0.336 bushing.

 

[JLM]

Re: Bushing Size

Guys, isn't the general rule:

2xneck thickness+bullet diameter and then subtract .002 from that?

Example: .308 Fed Brass .015 neck thickness=2x.015+.308=.338 Bushing=.336

 

[rijndael]

Re: Bushing Size

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JLM</div><div class="ubbcode-body">2xneck thickness+bullet diameter and then subtract .002 from that?</div></div>

I measure a loaded round @ the neck and subtract .002".

 

[USSR]

Re: Bushing Size

Bushing size is also dependant upon the difference between the as-fired neck size, and the amount you want to reduce it. For example, going from a .346" fired neck and using a .338" bushing yields you a .337" neck.

Don

 

[JLM]

Re: Bushing Size

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: USSR</div><div class="ubbcode-body">Bushing size is also dependant upon the difference between the as-fired neck size, and the amount you want to reduce it. For example, going from a .346" fired neck and using a .338" bushing yields you a .337" neck.

Don </div></div>

Why is that? I'm about to order an S-Type so anything you can tell me would be helpful.

 

[MitchAlsup]

Re: Bushing Size

If you size the neck too much in a single step, the size of the first step causes the brass to be oversized. ).005-0.006 is as much as you should size in a single step with a bushing.

 

[JLM]

Re: Bushing Size

By how much Mitch? Don seemed to indicate a difference of .001.

And ya this is a factory chamber. Fired necks are measuring around .343. That's with Hornady brass. When this lot is done I'm switching to Lapua