That third group shows real promise.
Indeed!
In that bottom group pdh,,,that outside shot, what number was was it in the sequence,,,just curious?
Looks to me, that it could be one of shooter error.
The other groups and most likely possiblity is,,,,,I'm assuming you started with a clean barrel, and that it can take some fouling rounds to settle in. 10 rounds seems high for this, but not unheard of. This is why I don't clean bore until accuracy starts falling off.
1-10" twist should be fine with most bullets up to 95 grs. and some 100's. With the 95 gr boattails and up however, I prefer 1-9" and faster yet for the 105 and up.
FWIW, I seldom shoot 5 shot groups. For load workup I shoot 3 shot, once I get something that shows promise I'll shoot a 3 rnd and wait 5 minutes, then shoot another 3 at same point of aim, wait 5 more mins. and shoot 3 more. I just feel this 9 shot aggregate gives me a truer sense of what the combination is doing. With lighter contoured barrel's, I wait longer.
Dave