Frank
I'm using IMR4350 for my Krags because that's all that was available at the time.  I got 8 lbs so It'll last awhile.  I've not tried to determine a performance difference between the two but I wouldn't expect to see measurable difference (but u never know) in POI or grouping up to 200 yds.  200 is all we shoot for matches. 
We'd be interested in your results, should you undertake a study.
Madsenshooter, what ye say?
Vic