Why have a crimp groove?

[milrifle]

Why do bullet designers put a crimp groove in their bullets if they know reloaders are going to experiment around with seating depth?

[Cherokee]

My quick thoughts: It does give a "normal" starting point, and not everyone does experiment so that becomes their crimp point.

[MtGun44]

Many are at a location that is "normal" or in some cases even maximum LOA for a particular weapon.

Bill

[Wolfer]

I personally always use the crimp groove on revolvers and lever action rifles. Hardly ever use it anywhere else.

[williamwaco]

I personally always use the crimp groove on revolvers and lever action rifles. Hardly ever use it anywhere else.

Ditto.

[geargnasher]

Sometimes it's needed to keep the boolit from moving. Gotta put it somewhere, and it's usually located in a place that sync's with SAAMI standard dimensions. Not all guns are made to or worn to SAAMI specs, though, which is another reason so many custom mould makers are quite busy these days.

Gear

[MT Chambers]

you'll want one and you'll use it on heavy loads for the .44 mag. and .454 casull in revolvers..also heavy 45/70 loads...without it you'll have failure at the worst time.

[JLDickmon]

Ditto.

double ditto

[btroj]

Having a crimp groove and not using it doesn't have a negative effect. Needing one and not having it prevent the bullet from being usable.
I would far rather have one than not. Like Gear said, ya gotta put it somewhere.

Want a groove in the exact place you want one? This is why we have custom moulds like Accurate.

[rond]

The groove is so you can seat and crimp in one operation without the brass shaving the boolit.

[milrifle]

Well guys, I feel a little better. I normally seat to the crimp groove. A couple of weeks ago, I tried seating out longer trying to engage the rifling on my 03-A3, and my groups doubled in size, so it went right back where it was. Maybe I'll try adjusting it again one day, but not now. I just read all this info on seating depth and thought I must be ignorant for just putting it in the crimp groove, but now I see I'm not the only one.

[runfiverun]

it also breaks up the drive bands otherwise you'd just have one giant long one there with no place for the the rifling to displace lead to.

[mdi]

Ditto.
Me too.

[Jim]

Another vote in favor of crimp grooves. especially in revolvers and levers as was mentioned earlier.

[Down South]

You'll find a crimp groove in most all boolits designed for revolvers or lever guns. They are there for a reason.

[MBTcustom]

Oh so that's what that small starter lube groove is for. Hush my puppies.:kidding:

[mpmarty]

Ya mean to tell me it's not a lube groove?