Scope question

[my70mav]

I just picked up my Armscor m20 .22 rifle and plan to use almost exclusively sub-sonic primer only rounds. What would be a cheap "walmart" type scope that I could use? It only needs to be good to about 50-75 feet. Also how do I know what style of attachment I would need? Thanks I dont know anything about this stuff.

[BSlacker]

You maybe confusing Sub Sonic with the low velocity primer only Colibri type round. Colibri exit at about 450fps, which is sub sonic, with a very light bullet (18gr to 20gr) and sub sonic means around 1050fps which will be below the speed of sound with a 40gr bullet.
It won't matter what sighting system you put on the M20 the bullets from the primer only rounds will stick in the barrel within a couple of rounds fired. The Colibri type rounds with primer only are intended for shorter barrel manually operated actions such as 16" bolt actions, which are about the safe barrel length limit. Semi auto pistols are a pain because you have to work the action for each shot but bullets don't stick and you don't lose any velocity compared to a revolver with a gap.
The M20 has a rimfire grove most likely 3/8th any Walmart Red Dot sight intended for this size grove will work fine. It should work if you want to give it a try just use normal 22lr.

[my70mav]

I was thinking the Colibri rounds, I will buy a box of 50 and see how it goes. I also just picked up little Crossman 4x15 scope for a couple bucks ready to go on a 3/8 dovetail. I live just outside of town and plan to to use it for light pest control, is 4x15 good for 20-40 yards?

[BSlacker]

[QUOTEI will buy a box of 50 and see how it goesQUOTE]

If you have the 21" barrel you will stick a bullet for sure!

[my70mav]

Can I have the barrel shortened to 16"? I am worried I will have trouble with the neighbors with the noise from standard rounds.

[BSlacker]

Why not just get a pistol? I use a Contender the 10" or 12" barrel with a red dot, no need for magnification at these distances, it is great for this and quiet. I shoot them in the garage often. Look at cheap pistols you don't need much maybe a Heritage. I have shot them from the little youth rifles that are cheap and short works great but not guaranteed. It is not too dangerous just won't work well enough to get any value from the rifle and could mess it up. Stick with what the ammo people say on the box.