determining the correct neck size bushing

[Remington243]

For getting the neck size bushing I need. I am confused on the measurement. The measurement on the bushing are referring to the inside diameter. So what I want to do is lessen the tension on the neck of the brass. I have been doing 308 with a bushing of .336, to lessen the tension I would go with .337, .338. Right ?

TKS
Bill

 

[TAJ45]

Right, larger ID means less squeeze.

 

[rwj]

Bingo!

 

[Mark M.]

This is what I do, Measure the neck thickness on a fire case, Double it, Add the bullet diameter, Then -2 thousands from the total, thats you're neck bushing size.

 

[Dusty Stevens]

This is what I do, Measure the neck thickness on a fire case, Double it, Add the bullet diameter, Then -2 thousands from the total, thats you're neck bushing size.

Or you can seat a bullet and measure the whole neck simply with calipers

 

[Mark M.]

Or you can seat a bullet and measure the whole neck simply with calipers

you could do that, and I'm no expert, but wouldn't one want there case neck to be as close as possible to there neck chamber dimension?

 

[Dusty Stevens]

you could do that, and I'm no expert, but wouldn't one want there case neck to be as close as possible to there neck chamber dimension?

No. You want plenty of clearance. With no room to expand to let the bullet go it becomes a bomb

 

[L.Sherm]

If you use an expander button with a bushing the expander size sets you tension as long as your going .002 smaller than a loaded round dia.

 

[muleman69]

For getting the neck size bushing I need. I am confused on the measurement. The measurement on the bushing are referring to the inside diameter. So what I want to do is lessen the tension on the neck of the brass. I have been doing 308 with a bushing of .336, to lessen the tension I would go with .337, .338. Right ?

TKS
Bill

What Dusty said is the easy way, you can also get your tension by measuring neck before seating bullet then subtract from seated dimension

 

[dgeesaman]

No. You want plenty of clearance. With no room to expand to let the bullet go it becomes a bomb

By plenty I assume you mean the usual .002 to .004 inches clearance on diameter.

David

 

[Dusty Stevens]

By plenty I assume you mean the usual .002 to .004 inches clearance on diameter.

David

More or less depending on your needs yes

 

[rwj]

By plenty I assume you mean the usual .002 to .004 inches clearance on diameter.

David

Another measure is that a bullet of the same caliber should be able to either pass thru the neck of a fired case, or reach its seated depth, with little axial force being applied...

 

[ScottVA]

Cut thin to win

 

[David Christian]

By plenty I assume you mean the usual .002 to .004 inches clearance on diameter.

David

Actually many competitive shooters are finding larger neck clearances such as .005 to .007 to be just as, if not more accurate than tight necks.