wyoming260,
OK then, I'll bite--but bet very few other people will now pick IMR4451.
I've had superb luck with IMR4451 in any cartridge/bullet combination where handloaders often pick IMR4350 or H4350, and it works as least as well with 165-168 grain bullets as either 4350. Velocity and accuracy are very similar, and 4451 is also as cold-resistant as H4350. Plus, it contains a decoppering agent, which works.
