I tried some 37 gr. HPBT in my 21" contender and they key holed, I don't know what twist it is but I sure don't have any trouble with 22 or 25Gr. What would make them key hole? I tried different powder charges it didden't make any difference. What do you think?

It takes a 1/6 twist barrel for those bullets.

I think most rifles in .17Rem. have a 1 in 9" twist. Your bullet is probably too heavy for your barrels twist. 1 in 7" would probably be close to ideal for your bullet weight in this caliber. Best wishes.

Cal - Montreal

not only is the bullet too heavy for the twist I think the barrel length is not helping you either.....it's not allowing the velocity to get up the rpms.....but I doubt a 26" barrel will work much better.....

As the others have said.....you need a much faster twist.