I just purchased and started using a Lee Factory Crimp Die on my .22 Hornet loads. The accuracy on some loads was unbelievably good and some showed no difference. I'm still experimenting with it. My question is, Does crimping increase / decrease velocity on the hornet round? Does it make any difference at all? Thanks

I haven't tried it on my Hornet, but I've fiddled about with it a lot on a 308 and a few other calibers. I've found a slight (in some cases very slight) increase in velocity. - Dan

The Hornet, as is standard, suffers from irregular accuracy. It also has very thin necks compared to other .22 centerfire calibers, especially the Swift. Some modern thinking theorizes that small rifle primers knock the bullet out of the case and into the lands before the powder really gets up and burning correctly (due to low neck tension). I really do not know, but some people have better luck with pistol primers and attribute that to not dislodging the bullet before the powder is up and burning. There is a group of shooters that now believes that the accuracy of the Hornet is improved by crimping, which delays bullet exit from the case. Maybe they're right.