That's how I fireformed my brass from 300RUM stuff before Remington sold 7mmRUM brass.
Rather than go through the whole procedure from scratch, jump over to www.reloadbench.com
& do a search for it under 'Fireforming' with my user name to narrow it down.
You'll burn the throat out of that chamber so fast, a little bit of breakfast carbs blown through there won't matter much...the alternative is blasting metal projectiles through the tube. Seriously, it may very well cause barrel wear, but it would take alot of testing through more than one barrel in a forgiving caliber to say for sure, IMHO.
Oh, when you shoot it, make SURE you're shooting downwind - burning Cream of Wheat smells like $#!^ !!!!!!!! [img]images/icons/shocked.gif[/img]