Getting ready to load for my Bergara premier chambered in 308 Winchester. I am using Hornady match dies. Factory loads seem to use .338 bushing size. What would be the best bushing size? Using Hornady brass and 178g eldx
The bushing size to use for whatever neck tension you're after depends on the thickness of the particular brass you're using. If you're after .002" of neck tension, measure the neck's diameter after sizing, then seat a bullet in the neck and measure the neck again. The difference between the two measurements will tell you your "neck tension" and whether that bushing is the size that gives you that or not. This technique is good without having to measure the neck thickness and do the math.Getting ready to load for my Bergara premier chambered in 308 Winchester. I am using Hornady match dies. Factory loads seem to use .338 bushing size. What would be the best bushing size? Using Hornady brass and 178g eldx
Getting ready to load for my Bergara premier chambered in 308 Winchester. I am using Hornady match dies. Factory loads seem to use .338 bushing size. What would be the best bushing size? Using Hornady brass and 178g eldx
It's all depends on how thick the case mouths are. If the thickness is .015", you multiply that by 2 . . . = .030".If I calliper a factory load in 178 eldx it comes out at .338. Hot much does brass expand when you seat the bullet in after resizing? I know that’s a very broad question, I’m just new.
It's all depends on how thick the case mouths are. If the thickness is .015", you multiply that by 2 . . . = .030".
Take that outside measurement of .338" - .030" = .308" which is the size of the bullet and means the neck wall thickness is at .015". If you want the "neck tension" to be .002", the neck needs to be the size of the bullet less that .002 . . . or .306. The size of the bushing should be .3055 to allow for some springback of ~.0005". But, keep in mind this is based on a case neck wall thickness of .015". The bushing size changes for that .0020" "neck tension" with a different neck wall thickness.
You're right, I didn't type what I thought I was saying. I've corrected it. thanks.That is completely wrong. OP do not do that.
Do like mentioned by a few above. Subtract .002" from .338 measurement you have of a loaded neck and it will give you .002" of neck tension. Most use from .001-003 in a bolt gun and .004" in a semi auto.