10-26-2023, 01:21 PM
I had only chronographed three loads in my Howa Mini 22 Grendel when I decided to re-chamber the Bartlein gain twist for the 22 Grinch. I was using Alliant PP2000MR with Berger 85.5 Hybrids and getting around 2950fps out of that 24" bbl. Like the OP, I wasn't having any luck finding load data, so just started out plenty low and worked my way up. I wish I'd seen the issue of Handloader with the 22 Grendel article in it - would've been very helpful.

