Mike Irwin
Member
Ringer,
A folded crimp is what you normally see on shotgun ammo. If you look at the top of a shell, you'll see folds, like petals of a flower, normally 6 or 8 sections. It's only when the petals are open (and the shell has been fired) that it is at its full length of 2.75 or 3 inches.
A shell with a roll crimp, however, has a flat overwad with the edges of the shell actually rolled down over it to hold it in place.
This kind of crimp takes up a lot less of the shell, and allows for more payload room. Roll-crimped shells, unfired, are almost the full length of 2.75 or 3 inches.
An example of the difference in the payload room it can make...
The standard loading for 00 buck in a 2.75" shell with a folded crimp is 9 pellets.
With a roll crimped shell, though, you can put 12 pellets into a 2.75" shell with no problems. The S&B 00 buckshot loads that I keep in the cuff on the butt of my S&W are roll crimped 2.75" shells with 12 pellets.
That translates into a significant jump in payload weight and total energy.
A folded crimp is what you normally see on shotgun ammo. If you look at the top of a shell, you'll see folds, like petals of a flower, normally 6 or 8 sections. It's only when the petals are open (and the shell has been fired) that it is at its full length of 2.75 or 3 inches.
A shell with a roll crimp, however, has a flat overwad with the edges of the shell actually rolled down over it to hold it in place.
This kind of crimp takes up a lot less of the shell, and allows for more payload room. Roll-crimped shells, unfired, are almost the full length of 2.75 or 3 inches.
An example of the difference in the payload room it can make...
The standard loading for 00 buck in a 2.75" shell with a folded crimp is 9 pellets.
With a roll crimped shell, though, you can put 12 pellets into a 2.75" shell with no problems. The S&B 00 buckshot loads that I keep in the cuff on the butt of my S&W are roll crimped 2.75" shells with 12 pellets.
That translates into a significant jump in payload weight and total energy.
