I need help with the length for "roll crimping" the 12ga 3.5"

[fireboy]

My first post & first shotshell loading:
I'm wanting to load some 12ga. 3.5", #4 buckshot loads. But I can not find the hull length for
"roll crimping" the 3.5".

Lyman 5TH Shotshell Reloading gives the "roll crimp" lengths for 2.75" and 3" but not for the
3.5".

I'm in fear of someone telling me you can't roll crimp the 3.5"!!!

Lyman 5TH Shotshell Reloading Pages 404 and 405:
MAX HULL LENGTH FOR 2.75":
ROLL CRIMP: 2.450
FOLD CRIMP: 2.405

MAX HULL LENGTH FOR 3":
ROLL CRIMP: 2.760
FOLD CRIMP: 2.655

MAX HULL LENGTH FOR 3.5":
FOLD CRIMP: 3.155

Any place you know where I can get it or can someone give me length from a publication that
you have?

Many THANKS IN ADVANCE.

[runfiverun]

your bbl will give you your maximum length.
you don't want the crimp extending into the bbl past the chambering step.
since you will probably be cutting the cases from fold crimped ones anyways.
i'd go right where they were formerly folded over, plus enough for the roll.
being a couple thou short on a shotgun hull will not deform patterns as the wad will carry over the small gap.
you'll also still have the same amount of hull capacity which will keep your loads more inline with published data for folded crimps.

[fireboy]

runfiverun Thank you!

You just confirmed my thoughts on what the book did not tell me.

Thanks again!