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
- Thread starter PRCslut
- Start date
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.
A .338" bushing is pretty big. I use an assortment of bushings for the various brass varieties I have. .336", .335", .333" and .331". My .331" if for some old Winchester brass that is very thin / light.
My .336" is for the thickest brass which is Federal GMM and some Military 7.62 NATO.
Before you buy a bushing (s), be sure of the size. I think .338" is too big.
My .336" is for the thickest brass which is Federal GMM and some Military 7.62 NATO.
Before you buy a bushing (s), be sure of the size. I think .338" is too big.
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.
I used the size of the loaded neck and then minus .002", which would be a .336" bushing. .338" is what my GMM loaded neck measurement is and I bought the .336". You could go with the .337" if you like.
I like having a little to work with in case you get a little variation in neck thickness. I do have mandrels if i need to adjust.
The .336" bushing on my GMM brass has produced very accurate ammo with the .002" neck tension.
Others will chime in to give their take on this. This is what has worked for me.
*Edit* When buying your bushings, I would recommend the SAC bushings. I'm not 100% sure they are compatable with the Hornady bushings, but I believe they are. They are a superior bushing. I Bought the Redding TiN bushings and if i was just starting out, I would buy the SAC bushings. https://shortactioncustoms.com/product/sac-neck-sizing-bushings/ SAC does say their bushings are compatable with Hornady bushing dies.
I like having a little to work with in case you get a little variation in neck thickness. I do have mandrels if i need to adjust.
The .336" bushing on my GMM brass has produced very accurate ammo with the .002" neck tension.
Others will chime in to give their take on this. This is what has worked for me.
*Edit* When buying your bushings, I would recommend the SAC bushings. I'm not 100% sure they are compatable with the Hornady bushings, but I believe they are. They are a superior bushing. I Bought the Redding TiN bushings and if i was just starting out, I would buy the SAC bushings. https://shortactioncustoms.com/product/sac-neck-sizing-bushings/ SAC does say their bushings are compatable with Hornady bushing dies.
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You might want to review page 3 of the dies instructions. You you didn't get as set with your dies you will find a link at near the bottom of this page.
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 interior needs to be the size of the bullet less that .002 . . . or .306. The size of the bushing should be .3355 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 .002" "neck tension" with a different neck wall thickness.
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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.
You're right, I didn't type what I thought I was saying.
I've corrected it. thanks.
