16ga.com ~ View topic - 6-point vs. 8-point crimp?

Joined: 05 Oct 2006 Posts: 3

What are the pros and cons of a 6-point or an 8-point crimp?

Previously I have tried to duplicate the original crimp when reloading once fired hulls, but I am now working with brand new BP-multi Hulls.

Is there any reason that I would want one or the other?

Spraiski

Member Joined: 27 Jun 2005 Posts: 1545 Location: Michigan

I think with new hulls, the 6 point crimp is easier. The crimp starter is important to get adjusted right. I always hold the lever down an extra second or two the first time I load new hulls. New hulls roll crimp like a dream, just a slower process. Wink

I am using 6 pt on BP-multi Hulls and they crimp up nicely using an over-shot card which I also got from BPI. I converted a PW 375 reloader from 12 to 16 with the latest parts and it does a very nice job.

For all practical purposes, either will do. Hulls meant to be reloaded numerous times like Remington STS hulls generally have 8 point crimps for 12 through 20 ga. hulls. The mouthes are believed to last a bit longer. Some folks hold that pressures are more uniform with 8 point crimps. I think that is splitting hairs. A properly formed and folded 6 point crimp will work fine.

The most important aspect of the crimp fold is the depth. The small rim around the outside is what locks the crimp closed against the top of the shot column. It also determines how much resistance is offered to the expanding gases upon firing. A too shallow crimp will open on its own. Too deep a crimp will raise pressures slightly and will overly stress the case mouth which shortens case life

Most 16 ga ammo has 6 point crimps. Just use the original number and you will avoid problems and find the right depth to do the job.

Member Joined: 08 Nov 2005 Posts: 3438 Location: Illinois

Be aware that certain hulls have different internal capacity when comparing 6 vs 8 pt hull.16 and 20 Remington Game Loads are examples--the difference is enought to effect the crimp.