doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com roll crimping loads/pressures

I want to load a 2 1/2" 6-7.5k psi low pressure 12 gauge shell for a damascus gun. Can I find a published 2 3/4" fold crimped load in the books I like, cut the shell to length, and roll crimp w/no worries?

Is there any historic information in DGJ, or any other resource, that may have some of this data?

Thanks!

Hodgdon has some 2.5 loads in their manual.

bill

Yes although I work mostly with 16 gauge loads it has been my experience that the roll crimped loads will generate about 400-500 psi less chamber pressure than folded crimped loads with the same components. In any case the chamber pressure of roll crimped loads will not be higher than the published pressure listed for the 2 3/4 inch folded crimped load.

I saw those too Bill and would have went that direction, especially w/the ease of conventional fold crimps. But, if I remember correctly, they are Clays based...and that's stuff is like hen's teeth right now. Thanks for the heads up though.

Few years back I posed the question to Tom Armbrust regarding roll crimps versus star crimps and pressure differences. Mr. Armbrust is a ballistics researcher and pressure tests shotgun loads for many people including firms supplying reloading materials and load data. He advised that roll crimps will generally produce lower pressures than star crimps by about 400 psi. Therefore I would be comfortable using star crimp data and roll crimping them.

Any published 2 3/4" load will fit into a 2 1/2" roll crimped hull.

I've been playing around w/an antique roll crimper I bought and tried it out on a dummy load in a paper federal just to see how it went. As you stated, everything fit perfect.

Thanks for the info everyone.

If you have a small drill press the roll crimper sold by Ballistic Products works great and is much faster.

BP roll crimper and homemade spring loaded shell holder for my drill press, it has a filler to load 16ga also.



My roll crimping loader, same loader works for both 12 and 16 gauge and I size with a Mec Supersizer


Most of my hunting loads are built around PB powder and light loads of ITX shot, 7/8oz for 12ga. and 3/4oz for 16ga for waterfowl and Lead Free upland. For lead loads I use B&P 1oz High Pheasants.