I have an H+R single shot 44 mag rifle that I have had for several years. I have used it for a close range deer gun, using mainly sub 44 mag level loads and taking advantage of the longer bbl to get adequate velocity for hunting. Doing this, I have also a very low recoil, low noise, effective deer rifle ideal for kids and people that don't really like recoil (me). Lately I decided to try heat it up a bit and get a little closer to 44 mag level loads so I could maybe stretch the range a bit. I found a lb of AA #7 in a pawn shop on sale for $21 which is CHEAP here. I loaded up some hi-tek coated 429421 sized .430 over 15.5 gr AA#7 and was able to get fairly consistent 11/4" to 11/2" round groups at 50 yds. The surprise came when I moved the target to 100 yds yesterday. I shot 5 shots at a 11/2' round circle from sandbags with the forearm rested on an adjustable Caldwell cradle (the same setup I always use) and got a 10" tall vertical string with the top hole right beside the spot. I don't see how that group could be "me", I have shot that setup alot with other guns and not had that result. I chronographed a similar load with 3 shots earlier (15gr) and got 2 in the 1480"s fps and 1 that was 1501fps. I added another 1/2 grain and it shot to the same POI at 50 and just as accurately, so I tried that one at 100 but didn't chrono it. I don't see how velocity variation could be responsible for this degree of stringing but maybe it is, I didn't chrono the 15.5gr load. Does anyone have any ideas I haven't considered?