I've been trying for a few years to make cutting edge's 22lr bullets produce the mythical microgroups--my experience is I've been lucky when I come close to equaling the better factory lead cast bullets ammo. There are several reasons for that IMO. First--most barrels are made to optimize conventional 1:16 twist lead bullets, unless you stick with CE's 32 grain bullets you're going to have rough sledding with those kinds of barrels. So you'll need 1:9 twist or better with the bigger bullets and, if I were to do it again, probably ream the chamber and freebore specifically for the solid bullet anticipated to be used. As I mentioned above--tolerances are much smaller in rimfire; the COL, rim thickness and even powder charge weight must be measured in much smaller measurements than conventional primered ammo--a range of charges need hundreths of a grain accuracy for precision. The real promise of CE's solid copper bullets is extra long range (i.e. 600 yds or more); which has been done in terms of "hail Mary passes" making contact but as far as I known they haven't really achieved reliable repeatable consistency at those distances. That supersonic to subsonic transition remains the "boogieman" in 22lr ELR as far as I can tell.
Sorry I lost track of it
Me too, sorry for dragging the topic down.