Re: Subsonic 22 for Spikes Upper
Don't have a Spikes but have a CMMG stainless steel bolt, dedicated upper. I have used CCI, Aguila HP 40gr, Aguila SSS 60gr. and all functioned flawless after about 500 rounds of cheap Federal bulk to break in.
Also take a serious look at CCI SV(standard velocity)40gr. at 1070 FPS. They are VERY accurate out of most guns and cycle great. I ordered 5,000 rounds for $270 shipped($2.70/per 50)but they are solids so might not be best if using for hunting...