I keep seeing reference from time to time for the rcbs 28 degree improved cartridges. Can anyone explain the pros/cons of this improved version over, say the 40 degree improved?

Less of an angle on the shoulder, theoretically feeds easier. Back in the day, every 'smith worth his salt had the secret shoulder angle stashed away that only he knew the true meaning of, the one magic angle that was the be all and end all of wildcatting shoulder angles. And that angle was.....drum role please....whatever he dreamed up and could BS his customers about. No really, everyone had slightly different ideas about what the optimum angle was, and as there really isn't any proof of one over the other, whichever you prefer is the right one. The 40 degree angle is known as the Ackley version, as he used it most (and possibly originated it. The 28 degree angle was the RCBS version, they felt that the 40 degree angle was too steep. Rockey Gibbs split the difference and his angle for his wildcats was 35 degrees. I have never seen a scientific study anywhere of whether any of these is "better" (for lack of another word) then the other, and I think it would be extremely different to prove one over the other. FWIW - Dan

[ 03-29-2003, 05:09: Message edited by: dan belisle ]

So, theoretically, the 28 degree shoulder would feed better, but the 40 degree shoulder would reduce case stretching better.

That seems to be the consensus, yes. - dan