Some 7X57 Case Capacities

[Andy]

At the Carp Gunshow yesterday, I picked up a bag of assorted 7X57 brass - 98 pieces for $10. The draw was the 45 new pieces of Norma, which alone typically go for upwards of a buck, but it also provided an opportunity to compare the case capacities of nine (9) different brands, and the differences were significant. Here is what I found:

All brass was F/L sized first and re-primed with a used primer - I did not trim them to the same length, but they all measured within 0.020" of each other. I then weighed them empty and then full to the top. Accuracy is probably +/- 1.0 gr of H20:

1. Imperial - 60.5 grs
2. Dominion - 58.8 grs
3. Frontier - 58.4 grs
4. Prvi - 58.2 grs
5. Winchester - 57.3 grs
6. Remington - 57.2 grs
7. Norma - 57.2 grs
8. Federal - 55.5 grs
9. "Met" (Swedish stuff sold by Higginsons) - 54.6 grs

That's a vast variation, in fact for a shooter using Win or Rem brass, you could save the money rechambering your gun to 7X57 AI and just seek out some Imperial brass, and gain the same 3-4 grs of case capacity and 50 fps at the same pressure. Of course that's not feasible as Imperial brass if obsolete, but it illustrates a fact - know case capacities before you change brass.

 

[Eagleye]

Andy, Some years back I had a lot # of Remington 7x57 cases that were heavier than any I ever saw of any other make.

Their capacity was so reduced, that a normal working load of Norma MRP in a Winchester case could not be put in the Remington case, even with a long drop tube.

I also had some of those Imperial and Dominion cases with lots of room in them, lol.

FWIW, in 300 Savage, the Dominion cases have the most room in them, by a fair margin.

Regards, Dave.

 

[remington jim]

Almost 6 grs variance - WOW big difference ! RJ