Noobie, 284 Shehane. What bushing?

[articmp]

What bushing do I need for a .313 neck? I plan on running the resized lapua and the winchester brass.

 

[Steve Blair]

What bushing do I need for a .313 neck? I plan on running the resized lapua and the winchester brass.

[br]
The bushing size will vary depending upon what tension you want to achieve and the neck wall thickness. The bushings vary a bit, too. Generally, .002" smaller bushing than your loaded round diameter but you will need to check that against your brass.

 

[articmp]

Ballpark for 2 or 3 sizes?

 

[Steve Blair]

My guess would be .311, but it could vary up or down.

 

[Ecomeat]

I have got a .313 neck on a straight 284 Win, and a .309 bushing seems to work perfectly, after I turned my necks to 0.013 to tidy them up.
So 0.013+ 0.013 + 0.284 is 0.310, which gives me 1 thou neck tension and 0.003 clearance. There are a number of references on this forum re accuracy problems (specifically with 284 Win) with 0.002 clearance, and less, so I decided right up front to run with 0.003 clearance, and so far it's all good.
I also got a .308 bushing sent over in case the 0.001 tension wasn't enough but haven't needed it.

 

[Elwood]

What bushing do I need for a .313 neck? I plan on running the resized lapua and the winchester brass.

308 or 309 is what you require.

 

[nosualc]

Can't accurately guess bushing size from just a neck size. We need to know the size of a seated bullet in your turned necks.

Seat a bullet into your prepped (turned) brass. Measure at the neck (it will likely be in the .308-.311 range for a .313 neck). Whatever your measurement, subtract .001 to get your bushing size for minimum neck tension. You can use smaller bushings than that to get more neck tension.

Example: you measure your seated cartridge to be .309 at the neck. Get a .308 and a .307 bushing for .001 and .002 neck tensions (respectively). Figure out which one works better for you.

-nosualc

 

[Steve Blair]

What bushing do I need for a .313 neck? I plan on running the resized lapua and the winchester brass.

[br]
Do you mean the loaded cartridge neck diameter or the chamber neck diameter?

 

[nosualc]

What bushing do I need for a .313 neck? I plan on running the resized lapua and the winchester brass.

[br]
Do you mean the loaded cartridge neck diameter or the chamber neck diameter?

LOL, I guess I read his original note as the latter! Yes, please clarify!

-nosualc

 

[effendude]

My Shehane reamer has a .313 neck. I run necked up Lapua brass that I turned nearly 100%. My fired brass measure .310 and loaded rounds measure .309 I am running a .308 bushing for about .001 tension with an allowance of about .001 for brass springback. It took a couple tries to find the bushing that was just right, I understand they sometime vary in diameter despite their label. Your bushing size will be dependant on loaded round size and the amount of tension you want to run.

Scott