I don't normally think of the Ruger as a consistent one hole group gun.
my distance is 10 yrds. in basement, 3 shot group , my rifle like jsb exact 10.34 gr in .177 cal. 25% of the time i can shoot a one hole group. The reading on a 6 shot through the chro. were one time with in 5 ft. per. second and the other time they were 31 ft. per. second?