With current load of RL26 3455 without the can but it is clearly near max. the H4350 accuracy is good but Vel is 3340 but low SD & ES. N550 at 41.6 gr is way hot and very temp unstable both low and high, at 40.5 gr it is ok with SRP Starline in temps 45-60degree vel is 3390. My ladder test with H100 was not satisfactory. safest powder is clearly H4350. RL26 has promise but is on hold til I get more of it. 37.5 of W760 may be the ticket also. This gun is throated long and I'm 20 off the lands.I just acquired 2 lbs of RL26 so I will be giving it a try. What kind of velocities are you getting from a 22” barrel?