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Posted By: Phunter roll crimping loads/pressures - 05/02/14 04:24 AM
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!
Posted By: bill schodlatz Re: roll crimping loads/pressures - 05/02/14 02:06 PM
Hodgdon has some 2.5 loads in their manual.

bill
Posted By: TwiceBarrel Re: roll crimping loads/pressures - 05/02/14 02:10 PM
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.
Posted By: Phunter Re: roll crimping loads/pressures - 05/02/14 03:09 PM
Originally Posted By: bill schodlatz
Hodgdon has some 2.5 loads in their manual.

bill


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.
Posted By: Jerry V Lape Re: roll crimping loads/pressures - 05/02/14 04:26 PM
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.
Posted By: David Williamson Re: roll crimping loads/pressures - 05/02/14 04:50 PM
Any published 2 3/4" load will fit into a 2 1/2" roll crimped hull.
Posted By: Phunter Re: roll crimping loads/pressures - 05/02/14 07:06 PM
Originally Posted By: JDW
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.
Posted By: Phunter Re: roll crimping loads/pressures - 05/02/14 07:08 PM
Thanks for the info everyone.
Posted By: Joe Wood Re: roll crimping loads/pressures - 05/02/14 07:41 PM
If you have a small drill press the roll crimper sold by Ballistic Products works great and is much faster.
Posted By: oskar Re: roll crimping loads/pressures - 05/02/14 11:02 PM
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.

Posted By: Buzz Re: roll crimping loads/pressures - 05/02/14 11:54 PM
That's a neat device. I don't know anything about roll crimp, but would like to learn. Can you use shells that have been star crimped for roll crimping? I hope this isn't a dumb question.....I really don't know anything about it. Where can I get good instruction as to how to? Thanks.
Posted By: TwiceBarrel Re: roll crimping loads/pressures - 05/03/14 12:17 AM
Originally Posted By: buzz
Can you use shells that have been star crimped for roll crimping? I hope this isn't a dumb question.....I really don't know anything about it. Where can I get good instruction as to how to? Thanks.


Previously fold crimped shells do not work well, however, if you trim a quarter inch off the end you get rid of most of the crimp and you will get much better results.

There are a number of posts on roll crimping posted on 16ga.com some using old time hand operated crimpers which I prefer and others using a variety of drill press mounted crimpers. You will also find a hull trimmer that you can make for less then a dollar that works better than anything on the market.

Good luck.
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