is there a chart that shows comparison of muzzle vel.to cartridge pressure such as 1300 ft. per sec. =30000 lb

Question

would really life to know this aboutn 45-70 cal.

Answer 1

Chamber pressures are listed in c. u. p . Copper units of pressure. I have a handloading manual put out by the NRA and the lowest velocity listed for 45-70 with pressure data is 1310@18,000. This is with a 405 grain Winchester flat nose bullet with 20.5 grains of Win630. Different powders achieve different pressures. Another load with a 405 Grain Remington flat nose with 41 grains of Hodgens BL-C(2) shows 1354@16,400. Get a good reloading manual and heed the warnings therein. Don't make reloads for a Ruger Model 77 and shoot them in your Trapdoor Springfield.

Answer 2

Try one of the ammunition manufacurers websites. They will probably have ballistics charts for the 45-70, assuming they load for that cartridge. The SAMMI specs for cartridge pressure should be found in most reloading manuals.

Answer 3

Buy some reloading manuals. They give pressure and velocity of various recommended loads