I got those old and beat up 512 Sportmaster from my late uncle many years ago which I repaired and mounted a scope on. More recently I picked up a 511 Scoremaster with a five shot box magazine in nice condition which I have never fired. The 512 is a 15 shot tubular magazine rifle with a long barrel. Very sweet shooting. The 511 differs only in the magazine. These rifles have such a good balance and feel. The 512 was accurate out to 100 yds (91m) but at 100m (109yds) the groups were opening up exponentially. Then I made a suppressor for it which really screwed with the accuracy. The baffles weren't perfectly aligned so I remade it. I also found the muzzle was badly worn so I chopped off the tip of the barrel. Thereafter it shot accurately.
Here it is with my late son, Denver shooting it.
I'm the guy in a hat coaching a youngster with a rifle I shortened for him. That's his mother (my niece) behind us shooting the cr@p out of us! That's not a bad thing - she is a very good shot! We were shooting beer cans at about 80yds and she was getting bored so she started shooting the cans on the rim to make them fly in the air! So I started shooting the bottom of the cans through the top opening - and I was standing (I actually got a few like that). Yup, that Sportmaster really shoots well. It must have had thousands of rounds through it. I was a silllywet champ with it when I was much younger. It now it is of special sentiment to me (Denver shot his first hare with it at a good distance two days later). I actually bought the 511 with my son in mind.
P.S. There are four Aspies in that photo! All good shots.