It takes a lot of work to be a good shot with a 22lr. One hundred yards is particularly stressing. Unless you are shooting good ammunition your groups will be poor. I can't define poor with standard, over the counter blasting ammunition, as I don't shoot it. Good groups are like these, fired by Joe Farmer at the Western Wildcat.
Joe was Senior US National Champion, and he was amazing. No doubt the shots out of the X ring are due to wind pickups and let ups.
Even with good 22lr ammunition, to have consistent grouping you must be a good wind reader, and conditions have to be consistent enough to deduce patterns. The good wind readers read the wind like braille. They combine multiple datapoints and conditions in their head, and figure out, what is "their condition". One National Champ told me "Pick your condition and shoot in it". A 22lr bullet has all the ballistic properties of a spit wad. It is amazing to me to see a flag flip as I break the trigger, and see how far the bullet moves from center. Very frustrating too, wind is chaotic, there is actually, no pattern to the wind, other than the one you assume is there.
Competitions put up flags between the shooter and target, so shooters can have an idea of what is going on down range. Reading flags, reading mirage, is a mystic art, of which, I am very limited. The good wind wizards see things I don't see, and shoot better for it.
Because of the wind sensitivity of 22lr's, unless you are shooting in a wind tunnel, you really don't know the ultimate performance of your ammunition.
Old rifles can shoot very well indeed. This Rem M37 was made in 1941, has a good barrel,
and in fact, appears to have been hand selected at Remington by a period shooting celebrity.
I was high shooter at the 100 yard stage, shooting two 20 shot targets, prone, with a sling, using that Lyman Super scope.
The basic problem these old rifles have, for competition shooting, is that the Army set the rules for the day, and they wanted shooters to shoot something that was as close to a service rifle as possible. Therefore the ergonometrics are closer to an oar, than a rifle stock. The Army finally backed off after their teams were being consistently whacked by Europeans and Soviets post WW2 in International Shooting. Those foreigners were cheating by using comfortable rifle stocks with lots of adjustments, and not adaptable for attaching a bayonet to the barrel!
Pointy sticks had to be pried from the hands of troglodyte infantry before they would grasp stone tipped spears. And for as long as they lived, retired troglodyte NCO's would claim that stone tipped spears were never as good as their old pointy sticks.