Dales the fellow I bought my 25-21 from was loosing just about a case a shot. The mouth of the cases were folding and completly destroying the cases. I changed the seating depth to where the bullet engraves completly through the baseband plus a tad more and I have not lost a single case since I made that simple change. I bought the rifle for my youngest grand daughter to shoot and she has well over 200 shots on just that one case. I personaly have not shot it much other than to get a load developed for here and the cases I have are both Bertram and Rocky Mountain. I prefer the Bertram having shot both during load development and I also did not loose a single case while using either of the two choices. She has shot half inch groups at 100yds. on more than one occasion while still getting used to the rifle and learning how to breech seat on her own. The 100yd. load is 8.7grs. of 300MP and Wolf small rifle match primers. The barrel is a 10 twist Douglas and the action is a Mos and it was Davids personal rifle. In speaking with David if memory serves me right he liked 9.2grs. of 4759 but its been so long now I forgot what primers he was using. He said it would shoot 3/8 inch groups at a 100yds. so I know I was getting close with the 300MP and the Wolf Match primers. The bullet being used is the 120gr. Mos and I have never tried the 4759 or any other powder to date but I did go through all of the typical variety of primers including the match grade Fed. and CCI.

I hope this somehow might be helpful.
JLouis

Dales I should have added that I do not use any wads the case has enough volumne that I don't have to worry about spilling powder into the chamber. 

JLouis

Dale you can do one of two things:
First bell the case mouth so when you put the cartridge in you feel the mouth scrape in.
The second thing is drop your load, put a cork wad at the case mouth and tip the case so that the powder is at the mouth. You may have to up your charge a tad to get back up to the proper velocity but this works.

40 Rod