30 nosler trim length

[Philward]

Why is it my 30 nosler cases never need to be trimmed? More to the point why are they so much shorter than the trim to length of 2.556"? They are mostly 2.536-2.542 it seems and been fired 3+times. Maybe not shooting it to potential and the cases just don't stretch? The chamber is pretty tight on this xbolt HCLR? New Nosler cases are 2.538. I have one case that has been fired that is right at 2.556 all the rest are at least 0.010"or more shorter.

 

[backwoodsshooter]

did you measure a new never fired case? have you measures each ensuing case after being fired?

how hot are your reloads?

 

[Philward]

New cases are 2.538, have a box right here. As to how hot the loads are, that's what I'm thinking, may be leaving some performance on the table. Used 210g ABLR and now on a box of 190gABLR. Used the 210's for hunting last year 74.5g RL22. Trying 7828 up to 78g and Norma MRP @77.5g with the 190's which seemed to group well the first time we shot them so I have 15 loaded up to try tomorrow, 10 with fired cases and 5 with new cases. Want to see how they group. The fired cases seem to be about the dimensions of the new cases, distance to datum 2.183 for new and fired are 2.185-2.184.

 

[Philward]

The SAAMI drawings show 2.556-0.020", so apparently up to 20 thou shorter that 2.556 is safe to shoot and I read that Nosler makes their brass at the minimum spec so 2.536. I thought this might be specific to the Nosler cartridges but it's the same for many other cartridges, 30-06 etc.

 

[MagnumManiac]

Brass NOT stretching is a good thing!
When I fireform 375H&H to 375 Weatherby, the cases shrink by .030" on average.
I have been shooting the same batch of 50 cases and none have reached the 2.850" length. At least 4 firings on most.
Wish my other brass would stretch at the same pace.
The sharper the shoulder angle, or in the case of the Weatherby the radius shoulder, halts brass stretch somewhat.
I wouldn't worry about cases not stretching, I would worry when they stretch too much.

Cheers.

 

[Philward]

How much weight variance in the cases will it take to affect accuracy? Was just going through the cases and I see 3 different headstamps but they are all nosler cases. One group of 18 has large print and are 259g, most of the rest have small print and are 279g including the new box I have from nosler, and 5 others have small print but it looks sharper and a slight difference in brass color and finish that are 283g.

Some are from a box of loaded ammo, I suspect the large print ones. The rest were cases bought from nosler. Not sure where the 5 oddballs came from.