Re: What rimfire caliber for LR training
With a little work, you can find shelf grade 22's that will shoot very will in your gun. Not match grade level, but more than accurate enough for what you have in mind. I have several heavy barrel 22s and a 17MH2 and I have found shelf grade 22 fodder that is more than adequate. I love the MH2 for the flattness and cool factor, but if I was building a serious trainer, the 22 would be the way to go.
Second and most importantly, the 22lr will more closely mirror the trajectory and wind capabilities of the 308 compared to the 17. The 17 is more like a 220 swift in that area. No comparison to shooting the 308.
The guys that are building rimfire trainers are almost exclusively going to the 22 LR. Manners is making a version of his T2 and T4 stocks for certain 22s also.