iwanadouble/500 Nitro

Precisely the point of going to the 45/90 WCF as you are not taking any chamber meat at all, nil, none, zip, the head and rim sizes are identical to the 45/70 you are literally just shaving 0.3" more length to the neck.

Compare the case dimensions. An important point is you can still fire 45/70 ammo as this part of the chamber remains untouched.

But, the extra case length is the lesser bonus, the big pay-off is it is in a double!

So what?

So the stupid OAL restrictions, (and flat nose slug requirement) that cripple the cartridge to feed it through a lever gun, are irrellevant.

You are free to relieve as much freebore as suits your whim.

Some of the bigger NE DRs came with a lot (0.75") of freebore, the thinking being it rounded the peak off the pressure profile.

So you can let it all hang out out front and, if the old timers knew their stuff, all for a lower peak to the pressure profile.

Relieving the throat makes for a whole different show.

You get more powder space for free. Your only question is what seating depth/crimp combo you require to hold the projectile under recoil?

Assume one diameter ie. 0.458", conservative?

Std 45/90 OAL 2.88" when using a 450gn Barnes Solid gives seating depth of 0.910" for OAL 2.880" with 53.6gns usable case capacity.

But with a throat relieved and a seating depth of 0.458 you get an OAL of 3.332" with 72.4gns of usable case capacity.

That is a big difference.

At 0.910" seating depth you are pushing the 450gn at 1,700fps, but, for the same pressure at 0.458" seating depth you are pushing the 450gn at 2000fps.

What pressure? SAAMI specification for the 0.444 Marlin (a modern straight wall cartridge for lever gun) is 42,000CUP, these numbers match to that (ignoring the long free bore = lower pressure claim) according to my you beaut ballistics program.

450gn at 2,000fps ............ and that is not pushing it (in fact deliberately and consistently erring on the side of caution).

450gn at 2,000fps ............ Buff?

Dream on.

AR2201
The sleep of reason breeds monsters

PS. this thing also comes in 30-06 SAAMI 50,000CUP, thats 19% more than the 42,000CUP for the 444 Marlin we are using as a reference.