Acceptable neck wall thickness for 43 Spanish?

[ohland]

Before I get too wired up, what is a reasonable wall thickness for the 43 Spanish?

The Jameson brass I got mic'd .011 (with a tubular mic)

What chambers now: .440 sized boolit (.439 with springback) and .022 worth of wall thickness, grand total of .462 in the neck.

If the walls are turned down to .008-.009, then a .445 with .016 to .018 worth of wall thickness should be snug (totals .461-.463)

I have a Forster original trimmer and a #4 collet inbound. I can grab the old retrobate's case turning attachment. Forster will be only too happy to machine a .439 case turming pilot.

[EDG]

Just be sure you have .001 to .002 clearance with a groove diameter plus .001 bullet.

A more prudent person might use .002 to .004 but I prefer a snug fit to make the brass last longer.

[ohland]

Just be sure you have .001 to .002 clearance with a groove diameter plus .001 bullet.

A more prudent person might use .002 to .004 but I prefer a snug fit to make the brass last longer.

Too much math doth make the mad...


What I think you said:

Loaded boolit should fit into the neck with .001-.002 wiggle room. The sized boolit PLUS neck walls (with .001 slop) should allow that .001-.002 wiggle room.

[EDG]

Yes but if you are using BP fouling may prevent chambering.


Too much math doth make the mad...


What I think you said:

Loaded boolit should fit into the neck with .001-.002 wiggle room. The sized boolit PLUS neck walls (with .001 slop) should allow that .001-.002 wiggle room.

[Bob Busetti]

My Lee sizing does not size the neck down enough to hold the 440 size boolit, not even with the expander out of the die. The only way I can get the boolit so it can't be pulled out with my fingers is to crimp the in the case.

[EDG]

I like the case mouth about .001 to .0005 smaller than the bullet for a single shot. I did not consider the 45-70 much of a repeating rifle cartridge.
Most cases are about .010 thick. So with a .460 bullet add 2 X .010 for a total of .480 cartridge neck diameter.
So I would want the neck to be .482. Black powder might need a larger neck.


Too much math doth make the mad...


What I think you said:

Loaded boolit should fit into the neck with .001-.002 wiggle room. The sized boolit PLUS neck walls (with .001 slop) should allow that .001-.002 wiggle room.