jwrowland77
Member
I have a question concerning case capacity as it correlates to pressure and MV.
I weighed two different headstamps tonight for .308 win....Winchester and Lapua. The Winchester had a average case capacity of 56.8gr. The Lapua brass has a average case capacity of 55gr a difference of 1.8 grains. The Winchester brass was the lightest of the two empty.
Now, when I did my workup in each brass case, my best load in the Win brass was 44.5gr of IMR4895 and in Lapua brass it was 43gr of IMR4895. Does this normally happen where the difference between loads worked up are close to the same in the difference of the case capacity?
I don't have a chrono...yet, but have a question about pressure and muzzle velocity.
With the Lapua 43gr charge, and the Winchester 44.5gr charge, would these have the same or close to the same pressure and/or same or close to the same muzzle velocity even though one had a lower grain charge, since the difference is in case capacity?
Just something I was sitting here thinking about as it might correlate to MV and MOA adjustment might or might not be the same.
Thanks,
Jeremy
I weighed two different headstamps tonight for .308 win....Winchester and Lapua. The Winchester had a average case capacity of 56.8gr. The Lapua brass has a average case capacity of 55gr a difference of 1.8 grains. The Winchester brass was the lightest of the two empty.
Now, when I did my workup in each brass case, my best load in the Win brass was 44.5gr of IMR4895 and in Lapua brass it was 43gr of IMR4895. Does this normally happen where the difference between loads worked up are close to the same in the difference of the case capacity?
I don't have a chrono...yet, but have a question about pressure and muzzle velocity.
With the Lapua 43gr charge, and the Winchester 44.5gr charge, would these have the same or close to the same pressure and/or same or close to the same muzzle velocity even though one had a lower grain charge, since the difference is in case capacity?
Just something I was sitting here thinking about as it might correlate to MV and MOA adjustment might or might not be the same.
Thanks,
Jeremy