303british fire forming to 410

[Cast_outlaw]

I know there a plethora of threads for this but finding load data is scarce I was wondering if a case load of 3f holy black would work with a cork wad tight on the top. It’s new year’s so I can fire form them at midnight to ring in the new year. If black won’t work what would with one of the fallowing propellents. Bullseye, red dot, green dot, blue dot, Vectan AS, Vectan A1, win 231, win 296, tightgroup, unique, 2400. Any help appreciated

[Outpost75]

Never tried black. Any fast burning pistol or shotgun powder will work, about 10 grains, one square of TP, fill case to mouth with Cream O Wheat and push plug of Gulf canning wax into case mouth, then point straight up when you pop. ANNEAL cases first!

[pacomdiver]

i did all my fireforming for 410 musket from 303 with 10g unique with a small amount of grits on top of that and a thin soap plug on top (push the rim into the bar of soap to hold it in) and shoot .

i never annealed the cases and only lost 1 out of 100 i did to a neck split

[3leggedturtle]

Never heard of any one using BP to fire form cases, will be interesting to see how it works! Todd/3leg

[lar45]

I watched one video of using BP to form 38-55 from 30-30, he split lots of cases.
Use the Cream of Wheat method, works great.