Powder charge for final fireforming of 38-55

[Bubba w/a 45/70]

Is there a decent powder charge for the final fireforming of 38-55 cases with the RCBS 378-312-BPS 38-55 boolit in place?

I'm not looking for anything in regards to accuracy now, just something to make the boolit go out of the other end of the barrel.

Hoping that something of a pistol powder will work. I have copious amounts of 700-X on hand; will this work, or is it too fast?

[Le Loup Solitaire]

I've done fireforming on a few occasions mostly with getting 30-40 Krag cases blown out to 405WCF and 30-30's to 38-55. After annealing which reduces the chances of splitting shoulders or necks, I used 10 grains of Red Dot (which is somewhat faster than 700X) and then packed the case with kleenex or ordinary bathroom tissue...wadded up and pretty tight. It makes a mess but it works and you don't need a bullet seated or wasted in the process. 700X should work fine, but you might need a bit more of it than 10 grains. I would start with the 10 grains and see how well that works and if necessary increase the charge. LLS

[Bubba w/a 45/70]

I used 10 grains of 700X under a crayon to fireform the 30-30 brass that didn't go through the resizing die. That crayon stuck into the .30 cal mouth of the case worked GREAT!

I'm going to do the "paper wad" route. I'm pretty sure that this will end up working as good as the crayon did for me earlier.

Thanks!

[beagle]

Take .30/30 cases. Deprime. Full length resize in a .38-55 die so that they will chamber all right.

Prime. Be sure and use large rifle primers here. I tried some junk large pistol primers and ignition wasn’t that reliable.

I loaded 11.0 grains of Unique in each case. Then ¼ sheet of toilet paper was wadded up and pushed in over the powder. The case was the filled up to the mouth with corn meal. A wooden dowel was used to gently tamp the corn meal. Then another ¼ sheet of toilet paper is used to seal the case mouth and hold the corn meal in.

In fire forming, I found that cases fired horizontally tended to stretch more on one side so I began firing vertically. The range safety guys really freaked at this until I explained what I was doing. About 95% of the cases will blow out nicely. The remainder will split and must be discarded and some will blow out only partially. These can be full length resized, then expanded with an expander and loaded and will blow out upon firing. As I was interested in a .375 Winchester length case (I still had the .375 Winchester), all cases were trimmed to 2.00” and chamfered./beagle