Have two MC Ace adapters for a 223 carbine; a stainless 22lr and blue 22mag. The LR has worked very well for working daughter up to the 223. Not target grade but fine for 30-40yd field work and plinking. The blue mag sleeve, for whatever reason, us virtually useless. May have to experiment with more brands of mag. Who knows?! As stated, with the bullet diameters, the assumption would be the reverse.