i have been reloading since '73. i have three dillons, a rcbs single stage, and i cast most of the bullets that i shoot. i have a decent selection of manuals that span decades. i also use online data provided by trusted sources, and i have a computer program that has manuals from several powder, bullet, and mold companies. i never use loading data from a fellow reloader 'till i confirm it's safety and viability through a trusted source. this being said, i still have problems with some reloading issues.... first, i noticed many many years ago, was the differences in recipes from manual to manual from different powder, bullet, and mold companies. sometimes, they are pretty darn huge!! some companies use specially made 'guns' for measuring velocity and pressure. they are of a locked breach configuration, and frequently have a longer barrel that is used in the load being developed. for instance, there is no way my glock can achieve the velocities and pressures indicated in the manuals due to the gas actuation of the gun and the shorter barrel. the published, pressures and velocities, cannot be used as a realistic tool. in all fairness, some manuals do use normal guns for velocity measurements. some manuals use C.U.P., and some use P.S.I. i know what they are, and how the measurements are arrived. i think using C.U.P., could prove to be confusing to a novice reloader. does anyone else wrestle with these issues?