question - I own an ATI AR Omni, presently chambered in .22lr - as such it wasnt considered a regulated firearm and did not have to go through a waiting period...however, it IS a multi-caliber platform(meaning I could swap out the .22lr upper for a .223 upper assembly. ATI even sells these rifles as a combo ppkg now) - can I use this as my exemption for the HQL Training?
You might be able to, but be very careful. Once you use it as an exemption it is forever registered in MD as a regulated firearm and subject to all of the laws that apply to it.