So ordered two molds from accurate molds, going to make 240 grain bullets no gas checks, and 200 grain with gas checks, have to use 416 gas checks i am told, thinking i need to find a .408 sizer for the .406 bore of these rifles, anyone else work with this caliber?

finally received my Accurate molds, real works of art, cant wait to try them out, one is 200 grain with gas check, and he other is 240 without gas check.
Hope to use the rifles for hunting, my late brother wanted to try the 1907 351 for hunting, but passed in 1995 so never got it up and running in time, now have two of them and recently acquired a 1910 401 and will be good to finally get it shooting.

This will be great to see. Good on you for bringing an old classic back to life.

So loaded one round with a new manufactured 401 case with a Buffalo bullet 200 grain soft point, on the left, with a 44 mag on right for comparison.

I have an RCBS mold that I am going to part with. It is a 41-260. I bought it to try on my 414 S Mag T/C barrel and never got around to it, before I sold the barrel. The mold is used -handles new. Notes in the mold say .407" and 257gr with 30:1 alloy. If you want to shoot a heavier bullet - PM me.