I have a 1884 trapdoor and have been shooting it for 40 years. I recently read that the new 45-70 cases are very short on volume, to handle the pressures of todays smokeless loads. I found a belt full, a Mills, blue web, w/a OHIO buckle, of really old 45-70 rounds. Frankford 85,89, 90, and USC, WRA, all 500 grainers. To check the volume issue I took 6 rounds of WRA to the range yesterday--------4 duds and 2 ingitions, BOTH smokeless! I believe in only BLACKPOWDER IN TRAPDOORS and that shook me. So much for shooting rounds of dubious origin. The WRA cases are of blackpowder era, raised bases, but loaded with GOD only knows what. I will fill the old cases with water and weigh the water and do the same with the Rem. cases of 5 yr. old Mfg. Anyway, I have read that there is no way 70 grains of BP can be put in todays 45-70 cases. In trying to do that I have never been able to seat 500 grain bullets on 70 grains of 3F, by volume. Any body been down this trail? Thanks, ED.