ORIGINAL: Vapodog
there's only two instances where crimping is necessary.....
1. on heavy recoiling revolvers
2. on lever action guns and other guns with tubular magazines.
If your .243 is not crimped at all there's nothing wrong.....if crimped poorly there's still nothing wrong.....unless you've buckled your case and the shells won't fit the chasmber.
I'd recommend just not crimping at all in the .243
Roger that! Nor in any cartridge that you can find some other way of keeping the bullet from moving! (Like use of an undersized expander button!!) The more a bullet is deformed before it gets into the air, the less chance it has to be accurate!!