Hi Marc, the Dr Findlow article I was referring to is in Volume 18 issue 4 Winter 2007 of Double Gun Journal. Dr. Findlow IS a rocket scientist and really knows his stuff. I've talked to him many times. What 500/450 chambering do you have? I owned back in 1973 fully cased in oak and leather will ALL original loading tools and accessories an Alex Henry 500/450 3 1/4" Magnum BPE double rifle made for the Maharaj Rana of Dholpur. Needed money at the time and sold it. Have been trying to find it ever since, dang it!
I would not be too worried shooting lead bullets a little over size, but would be really concerned with oversize jacketed bullets.
By the way, almost all Henry double rifles came cased with a bullet mold numbered to the rifle. You really need to mike the bores to see what you have. An Alex Henry double rifle Dr. Findlow owned had a bore of .04564 at the breech and .4530 at the muzzle! Of course these are all Black Powder rifles.
