Quick answer 1" groups @ 50 yds with el cheapo ammo NO, even with a "match" chamber there are to many varables, your rest, your techneque [sp] the scope,and you want to do it with El; Cheapo ammo.
You don't need the $ 10.00+ a box to get good ammo, Fed. 711-B, 719,CCI standard Vel. CCI sub sonic, Wolf MT,
I would get 1 box of several different brands, and try to pick a calm day to test the ammo. AND take a cleaning rod and a couple of "mops" or a good supply of patch's, NO brush's. It will take +- 10 rounds of a different brand of ammo to "season" your barrel to that ammo
Go to the 22 rimfire forum and read, join and ask, a pretty good bunch of people