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338 Lapua brass still not close to Max Headspace

kdumph

Well-Known Member
Joined
Jul 5, 2013
Messages
76
I'm on my 4th firing of this Lapua brass, FL sizing every time and i'm still a ways away from the max headspace on my rifle (2.749). I'd like these to be just short of that max measurement, but my cases average around (2.716) after FL sizing on my 4th firing. Is this normal, figured I'd be trimming by now? In the name of consistency should I just trim these all to my shortest case?

Anyone know what the 338LM brass length is new? Could I be losing some major accuracy due to the short brass here?
 
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It sounds like you are pushing the shoulder back way too much when you full length resize.
If you don't have a neck sizer...just back off the full length diie until you get the case to headspace
the way you want.
After reading your post again it looks like you don't mean headspace but case length.
I would keep them at saami dimensions for max. Many shooters do trim to the shortest case length to keep them all standard.
 
I'm only pushing the shoulder back .002 if I remember correctly, so barley any at all. I do mean headspace also, I measured the headspace in the rifle and from what I have read unless I misread, you want the case length to be just short of the max headspace in your rifle.
 
You have your terms confused. Those numbers you are quoting appear to be chamber length vs case length. Headspace is a lot shorter than either of those. The maximum Headspace on a 338 Lapua will be about 2.362".
 
The specs I have for a maximum case length is 2.724" and a minimum chamber length is 2.734".

If you have measured your chamber at 2.749" and your brass at 2.716", that gives .033" clearance. Typically the minimum clearance is about .010" with an allowed .020" trim added to that. There is nothing you can do to close yours up except keep shooting. I think you are concerned about nothing.
 
There is no reason to bump the shoulder unless you have trouble chambering the brass.

Fire the brass, and do a neck size only if it is hard to chamber size it only enough to close the bolt.

This will tell you what your chamber size and make your brass last for a long time.

There should not be any head space after firing.

Case overall length should be .020+ less than the chamber length to prevent crimping the brass
on chambering. If a bullet will not go in the case mouth after firing the case is to long and is being crimped.

J E CUSTOM
 
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