I had a .222 target rifle built with a 1:7 Gaillard, that rifle shot everything well, with two exceptions. The jackets on Sierra Blitz and Hornady SXs were too thin and the bullets wouldn't make it to the target. The stubby little 52 gr Sierra MKs shot like crazy in that rifle. A 1:9 will shoot almost any .22 bullet you come across, except the heaviest TSXs which require 1:7 and the 80 gr match bullets. I'm not sure how well thin skinned Hornet type bullets would stand up to it though. With a standard 1:12 twist, the Speer 70 gr round nose shoots alright, but its only marginally stable, so thats about as long as you can go. I like fast twists though. There's not much a slow twist can do that a fast twist can't as well or better, with the exception of Hornet bullets, or maybe shooting cast. Cast bullets and fast twists are a poor combination.