The Crosman 150s are not since they are single shot. Cr600 is since you load 10 rounds at a time, one behind the other. Wadcutters are the best choice and I've been waiting for NOE to make that mould available for nearly a year now.
Cr150 on the other hand, I've shot pretty much all commercial available pellets and the ones cast from NOE moulds, including the slugs. Crosman 600 is .22 caliber, I'm not sure they made one in .177.
Cr150 is .22 caliber and Cr157 is .177 caliber.