I think it's the overly-narrow driving bands that's the limiting factor even with a gas check. When pushed hard and fast the little bands give up and accuracy starts going south. Recovered bullets show significantly widened engraving marks, but usually don't lead due to the gas check doing its job.Yes, that is the " catch " with this one since it is a plain base.
I agree with the above in regards to the 30 cal Loverin's, but the 22 is grouping better than factory ammo at around 1750fps.Like mattw, #225438 from an early mould that casts at .225" is the only one that ever shot well for me. BUT you can shoot his designs very fast if you like 6 MOA.