I know Hornady is thin-walled brass, and Nosler is thicker. 57.1 rs of N170 out of Nosler brass 147gr ELDM produces avg velocity of 2970 with stiff bolt lift. 57.3 grs of N170 147gr ELDM Hornady brass AVG Velocity of 3,070 and cases extracted with zero resistance. Why?
- Thread starter Iron Worker
- Start date
Thinner wall might mean greater capacity which would lower pressure....
Because Hornady brass is harder.
I'm no expert but here are my 2 cents anyway.
I'd measure the case capacity of both fired cases in grains of H2O. It seems likely from the velocity data you have that you would find the fired capacity of the Nosler brass to be greater than that of the Hornady brass. If that is indeed the case the larger internal volume of the Nosler brass would almost certainly result in a lower pressure and explain the drop in velocity you are seeing.
Just my wild guess.
I'd measure the case capacity of both fired cases in grains of H2O. It seems likely from the velocity data you have that you would find the fired capacity of the Nosler brass to be greater than that of the Hornady brass. If that is indeed the case the larger internal volume of the Nosler brass would almost certainly result in a lower pressure and explain the drop in velocity you are seeing.
Just my wild guess.
