The Firing Line Forums - View Single Post - if you could design a rifle, what would it be?...

animal · April 21, 2012, 01:24 PM

On your cartridge again … a .357 bullet will not fit in a .223 Rem case. The case would have to be expanded at the end rather than necked down. A..338 bullet gives you a more-or-less straight case that would have to headspace on the case mouth … bad juju that gets worse the more power you try to squeeze out of it (and oddly enough also bad juju in very low loadings with heavy bullets, but that’s another subject).

If you want a necked cartridge to solve the headspace problem, you need a bullet diameter smaller than .338, or a case with larger diameter than the .223
Also, when you start packing powder behind a heavy bullet, the pressure curve can skyrocket if you’re not careful. Selection of powder and and other factors can become critical.

If you want a .357, a starting point might be to look into the .357 Herrett. If I remember correctly, it’s in the power range you’re looking for. Anyway, if it is, note its case capacity (with the bullet seated) and then find a rimless case large enough to neck down, cut down, whatever… so that the case capacity of your rimless cartridge is at least as much as the Herrett. A little extra case capacity is usually better … safety for you

….
And a playground for handloaders

Your flip-over bolt sounds like a neat idea.

April 21, 2012, 01:24 PM	#25
animal Senior Member Join Date: April 28, 2000 Location: Mississippi Posts: 705	On your cartridge again … a .357 bullet will not fit in a .223 Rem case. The case would have to be expanded at the end rather than necked down. A..338 bullet gives you a more-or-less straight case that would have to headspace on the case mouth … bad juju that gets worse the more power you try to squeeze out of it (and oddly enough also bad juju in very low loadings with heavy bullets, but that’s another subject). If you want a necked cartridge to solve the headspace problem, you need a bullet diameter smaller than .338, or a case with larger diameter than the .223 Also, when you start packing powder behind a heavy bullet, the pressure curve can skyrocket if you’re not careful. Selection of powder and and other factors can become critical. If you want a .357, a starting point might be to look into the .357 Herrett. If I remember correctly, it’s in the power range you’re looking for. Anyway, if it is, note its case capacity (with the bullet seated) and then find a rimless case large enough to neck down, cut down, whatever… so that the case capacity of your rimless cartridge is at least as much as the Herrett. A little extra case capacity is usually better … safety for you …. And a playground for handloaders Your flip-over bolt sounds like a neat idea. __________________ Keep smiling ... it'll just make 'em wonder what you're up to...