fireforming methods

[midnight]

I have fireformed 219 Wasp cases using a moderately stout charge and have necked down 338 WinMag cases to 30-338 but my brother has a question I am not sure how to answer. He just got an ar15 upper in 300 OSSM. This is the Winchester super short magnum necked up to 30 caliber. The closest existing case is the 25 WSSM and that is what factory (HSM) loads are made from. He was thinking of fireforming them up to 30 cal using lead bullets so his bore wouldn't be damaged. I would probably use a pistol powder with cream of wheat and a wax plug in the case mouth to fireform. To me, a better alternative would be to use a series of expander plugs(6.5,270,7mm, 30) but he doesn't have any of these. Any suggestions?

Bob

[bydand]

Your cream of wheat idea is better. But you don't need a wax plug, just a little bit of Toilet paper to keep the contents from falling out. Just did 50 7.62 russian cases to 8x57R Steyr.
I figure after a couple of reloads, the cases will elongate those silly 3mm.:wink: