From 25 to 100 I get a 10 to 12" drop. So a 3to 4" drop would seem to be pretty good..... what ammo are you shooting?
I found CCI Blaser 40 gr Lead round nose (no hollow point) to give me the best groups out of both my MKII and my 10/22 (Green Mountain Barrel)
I prefer American Eagle 38gr Hollow points for hunting (gophers and wabbits) best accuracy in all the hunting ammo I have tried.
I have tried everything I have been able to get my hands on, Winchester: 333, Dynapoints, Dyna GT, Wildcats; Federal: Champion, Target; American Eagle: 38gr HP, 40gr Lead RN; Thunder bolts, CCI: Velociters, Stingers..... and a few others I can't remeber off the top of my head.
I have tried Eley Match ammo and Lapula Club, both group well but I find the same issuses as posted above..... I seem to have to work really hard to get good groups, whereas with the Blaser, good groups just seem to "happen".
All in all YMMV, you have to test various brands and types of ammo to find the one that works best for you.
Cheers!