Here's what we got so far...
My son’s Marlin 1894 'microgroove' shoots two very different factory loads, plus all three ranges of handloads with 2400, all to very close points of impact at 50 yards:
If you let him count the one to the lower left as a ‘flyer’ it shot 10 shots of five different loads into a center-to-center 3-inch group at 50 yards! The ‘E’ load of 21 grains Alliant 2400 was 1-1/4" center-to-center. We only shot one round of the 180 grain factory UMC and one of the Winchester 240 JSP, due to scarcity, and just wanted points of reference anyway.
My Ruger 96/44 is more picky; it has shot 1-1/4" groups at 50 yards with the Winchester 240 JSP’s but the other loads it did not like as consistently, showing a lot of stringing (we didn’t do any prolonged barrel cooling, although we shot our strings of three then waited a minute with action open). It held last-year’s zero nicely with the Winchester factory loads, but as before, places the 180 grain UMC’s way high and slightly right (always does this). My handloads from that gun all bear left, (again, consistently), and it looks like the 20.3 or so will equate closest to factory loads in that gun. Why they consistently shoot left from the same gun same rest same shooter still amazes me.
Next session with that gun and I think I will lose the barrel band and see how it shoots. While the accuracy with factory loads has been satisfactory - compared to the Marlin, it is very picky. I also may try a bit longer overall cartridge length.
The Ruger 77/44 is less picky, and if you exclude the lightest handloads, put the two different factory loads and two of the three handloads within a 4" circle vs. the 3" of the Marlin. It sure didn’t like the light loads, though! The circles drawn for the heaviest handload were due to using a different aiming point, so I traced the impacts onto this target. The 77/44 also has a really deep firing pin protrusion, and punctured a couple primers, though I don’t know if that affected group size.
If we go with just one load, we’ll probably go for the 20.3 grain load - it was 2.25" in the Marlin 1894, 2.5" in the Ruger 96/44, and 1.75" in the Ruger 77/44, and within 1 to 2 inches of the point of impact of the WW factory ‘reference’ load in all three guns.
Anyway, just some 44 Mag range reports, to annoy whoever is yearning to post the "Too Many Off-Topic Posts" post (...it's due any time now...
).P.S. We added my daughter's Puma 16" 44 Mag - posted below...
Cool !! My 1894P absolutely loves the Winchester "White Box" 240 JSP's. sighted dead on @ 50 yds it's a perfect little monster..... 
Thanks, Tom
