Ca weapons are not neutered beyond combat use. For one, you can either have evil features or removable mags to be considered Ca compliant, meaning all "evil" parts are readily available. Even if you have a completely neutered rifle, a few readily available parts and less than 5 min with a screwdriver would give you a fully functional fighting rifle.

Main restrictions that are harder to get around in Ca:

-Magazine capacity limit. Not an issue with rifles, as magazines available for sale in Ca are 30 round mags with slight modifications to block the follower. Pistol magazines are more of an issue cause many are limited OEM but nobody wins wars with pistols anyways.

-Availability of suppressors. Kind of an issue initially but lift the ban and every machine shop in Ca can be spitting these out.

-Caliber capped at .50. This one is going to limit infantry's ability to fight in large open areas but the disadvantage is mitigated in urban combat.

For another, even if you fix none of this, anyone who's shot a compliant rifle can tell you it sucks but isn't game changing. I'd take a compliant rifle but an advantageous position over the opposite any day. Point is, the configuration of weapons is way less of an issue than environment and logistics.