” Really liking the small bores I thought I'd like to see what I can work up and shoot in the Season Benchrest Postal Matches with this gun. I doubt if I'll even come close to winning but just want to see if the .22 caliber can be made competitive."
Pete,
You may do better than you think. The 22 caliber can be made competitive. I have been shooting CBs in the 222 and the 223 for 45 years. I think it was in 1977, in perhaps the first CBA postal match, I came in second in production class with a 222 Sako and first place went to Norm Duesterhoeft shooting a 223. I have won a lot of postal matches with a 223 since.
There has been a lot of improvement in CB shooting since 1977 and almost all the effort has been on the 30 caliber. Glad to hear of another shooter working with the 22 bore.
Like others who have commented, I have had the best luck with the 225415, if limited to the 14 inch twist although I couldn't never get better than 1.5MOA as an honest average of several groups. Loads that shot best always seemed to be equivalent to about 6 grains of 2400 and the bullets were wheel weight metal or something of about that hardness. I agree that it makes an excellent squirrel combination.
The main problem with the 222 is that all the factory rifles have the stupid 14 inch twist which as you have found limits you to short bullets. The 415 bullet has the same sectional density as a 105 grain 30 caliber bullet and you won't see 105 grain 30 caliber bullets winning any cast bullet matches. Long cast bullets are just plain easier to shoot -- look at the match results.
Fortunately because of interest in shooting the 223 in high power matches, and the military finally smartening up, you can now get a 223 in a eight or nine inch twist which will stabilize longer bullets and make the 22 easier to shoot. ( Savage has been offering 223s with a 9 inch twist for years and more recently Ruger, Winchester, and Tikka have seen the light) For more of my biased opinions see my article in Joe Brennan's “Cast Bullets for Beginner or Expert” -- either the first or second editions ( both are for sale thru the CBA -- see inside the back cover of the Fouling Shot). I recommend either or both books for a wealth of information -- some not available any place else.
Have fun with the 222. I have two of them that I enjoy. But if you decide to get serious in the postal matches I think you will find more success with a faster twist and longer bullets. Either way, I encourage you to give it a try. It will be nice to see another 22 shooter in the postal match results.
Good luck,
John