That sounds very reasonable to me. I like to operationally define rimfire accuracy as the average of XX consecutive 5-shot groups shot at 50 yards (although we could use 100 yards). The larger XX is, the better, and the
consecutive part of this is all-important. It means no cherry-picking groups; you use
all groups shot with that ammunition in calculating the average.
From what I've seen and read over the past nearly year and a half since I started this thread, with ammo it shoots best (which usually means the top makes/lines--RWS R50, Lapua Midas+, or Eley Tenex), with good bench equipment, and under good calm shooting conditions, a typical 1710 HB will probably
average, for 50-yard 5-shot groups, in the .30" to .35" range (with no cherry-picking!).
A 1710 HB will not equal an Anschutz 54-action single-shot target or BR rifle. There are several reasons for this. First, the barrel, although fairly heavy, is not the weight of the barrels found on the single-shot 54-action rifles, the 1907, 1913, 2007/13, and 54.30. Second, the 1710 HB will not have a true match chamber, something found on the models just mentioned. Instead, it will have a fairly tight, but not-quite match-dimension, chamber--this to allow foolproof chambering from a magazine. Third, a 1710 HB is a repeater, with the cutout for the magazine in the action floor. This results in slightly less stiffness in the action on firing than found with a single-shot action that has a solid, unbroken action floor. Fourth, the 5096D or 5109 trigger in a 1710 HB is not in the same class as the excellent 5018 trigger found on the single-shot Anschutz match rifles noted. Fifth, the stock of the 1710 HB--owing to the cross-sectional contour of its forend--will be less well-behaved on the bags than those of the match rifles, particularly the BR-configuration models. This will make it harder for the shooter to realize the true accuracy potential of the 1710.
These differences will account for somewhat larger groups for the 1710 HB. With a BR-configured Anschutz 54, like the 1907, 1913, 2007/13, and 54.30, I would expect
average group sizes (again all groups shot used in the average) of around .25"--again assuming top-of-the-line ammunition, good bench equipment, and good calm shooting conditions (and, of course, some competence on the part of the shooter). We have read of groups in the 1's shot with these Anschutz BR models, but again I'm talking here about
averages, not the best groups shot. Some will do better than this, some worse, but--on average over a number of these rifles--my estimate is about .25".
Finally, just for context, I would estimate that the
honest average for the Anschutz 1712 (again with top ammunition, good bench equipment, and good calm shooting conditions) would be a little larger than the figure I've estimated for the 1710 HB--something on the order of .35"-.40". That follows from (a) the lighter barrel on the 1712 and (b) the abominable skinny schnabel forend on the 1712 that is hard to control well in the bags. This figure also agrees with my own experiences with a couple of 1712s.
So I'm throwing out my estimates here, based largely on range reports filed by many shooters on this forum. Your experiences may suggest otherwise, so please feel free to correct any points you consider in error.
Edit: I should have added, in my estimates, that I've assumed a good fairly high-power scope in all cases.