I agree with buying better ammo to get better groups from a .22 rimfire. CCI SV is pretty decent mid priced ammo. Moving up to something like SK Standard Plus might improve your groups without a huge price increase, but of course each rifle is somewhat unique so you have to try different types of quality .22 ammo to find out what shoots the best.
BTW, EdM must have a really nice 10/22, probably with an aftermarket barrel. The groups with SK Rifle Match and Biathalon Sport are very good!
