Lapua brass

[DEW]

Loading for my 338 Lapua. New Lapua brass. Berger 300 grain bullets. Loaded round is .375 at the neck. That makes the neck thickness.0185. Everything I have read says Lapua brass come in at .0145-.015. In order to use my bushing die and keep my neck tension @ .002 I would have to trim the necks. Is this common for Lapua brass? Thanks Dew

 

[Bravo 4]

Not be a smarty pants but wouldn't it be easier to get the appropriate bushing?

 

[DEW]

Largest bushing is .369.

 

[jdg300rum]

I run a .365 bushing with lapua brass and 300 grain berger

 

[gohring3006]

I wouldn't worry a whole lot about it until you fireform them.

 

[J E Custom]

I prefer neck turning new brass to get it the thickness you want before firing it the first time. This makes it very uniform and easy to select the best bushing for proper sizing.

First measure the neck of a fired case to dimension the neck chamber. Then add the bullet diameter + the amount of neck tension you want. (Normally .002 to .003 thousandths) and compare that dimension to the fired case neck. This will tell you how much neck wall thickness it will take to give the case .004 to .005 Thousandths to expand and release the bullet.

Armed with this information, follow the instructions by the die maker on selecting proper bushing diameter.

J E CUSTOM

 

[dok7mm]

Yes, you need to know what your chamber neck diameter is. If you have access to the reamer print, it will show you. If not, measure several fired cases, as suggested, and add .001" for spring back and you will be close.

Not familiar with .338 Lapua brass, but that sounds thick. If all your brass is that thick and .369 is largest bushing, you have one option, that I can think of.

Use your largest bushing and then run a .336" mandrel to set your .002" tension. Remember that it is actually the amount of neck that is sized and not the bushing that determines your actual tension.

If it was mine, I would turn the necks for .004" overall clearance in the chamber neck, as J E recommended. If that is excessive vs chamber neck, at least turn to the thinnest side of your brass. FYI, the proper tools for neck turning can be expensive. The expander die and mandrel combo are a lot cheaper.

 

[DEW]

Thank you for the replys and info guys. Its greatly appreciated. DEW