Neck Tension for 44 mag loads....expander size?

[guywitha3006]

Good morning everyone. I recently picked up a 629 and want to put some ammo together. Loads will mainly be 240 grain cast boolits at about 1200. I bought a box of SmS cast to get me going until I figure out what mould to go with. So finally the actual question, the expander in the RCBS die set seems fairly small and ment for jacketed, so I plan to turn a better size for .431 cast boolits this weekend, but 44 mag is a new caliber and I don't know what neck tension is needed. I was thinking of making a .430 or .429 expander but I am not sure if that is enough tension. I feel as if I am over thinking this one, but figured I get some advise from those who have been there done that...so Thanks in advance!

[Outpost75]

Normal practice for loading of lead bullets is that the expander plug should be 0.002" less than bullet diameter. If you are loading .431 bullets in your .44 Magnum a .429 plug is perfect, if that's what it really measures. Most plugs marked "429" will actually be about 0.001" smaller to compensate for hoop stress and springback in the sized case. In the majority of cases that will also be OK. This is because in brass which has been fired and reloaded several times, then full-length sized and expanded, some work-hardening takes place, so if you checked your sized, expanded cases with pin gages after expanding with a .429 die, you will find them .4295-.430, but a .430 plug would give a loose mouth which won't hold your .431 bullet.

[guywitha3006]

Thanks Outpost, I will probably end up making an expander. I don't remember the exact dimensions but I want to say the supplied expander was in the .424-.426 range. It was small enough to concern me about swaging the bullet down.

[randyrat]

Your on track..The .424-.426 is more for Jacketed bullets..I figure 2-3 K squeeze for Cast bullets and 4-6 K for Jacketed

[OS OK]

As long as you are putting this much work into it...I'd load a few, let them sit for several days and then pull them down and measure them.

I'm thinking that 'uniform annealing' throughout your brass supply is going to be the final factor...

[DougGuy]

If you make one, make it long enough that it will expand where the base of the boolit goes so it doesn't swage the base down unnecessarily.

[guywitha3006]

Thanks for the words of wisdom. This is getting loaded into new Hornady brass(it is what I could find locally instock). I've reloaded cast before but this is my first venture with the 44 mag and for some reason I feel like I am over thinking it. Dougguy, my plan is to measure from the crimp grove to the base of the Boolit and use that for my expander length.

[DougGuy]

Dougguy, my plan is to measure from the crimp grove to the base of the Boolit and use that for my expander length.

That's exactly how to do it!