....too short...?
Commercial ammo should not pose any feeding problems....usually. However,as with all military weapons,soft point hunting-type ammo may not feed as well as FMJ. Each gun has its own quirkey problems...some will feed OK....some won't. All you can do is try. Just make sure all lube points are just that...lubed up. DO NOT lube ANY AMMO....!!! I would suggest that you shoot a few FMJ rounds first,warm it up,check headspace (again) and then try the commercial ammo.