Maryland residents are again penalized in Pennsylvania. Under the current PA CCW permit policy, a non-resident of PA cannot obtain a non-resident CCW permit unless they possess a CCW permit from their state of residency. So, even though I have a Utah non-residence CCW permit, PA will not honor it because I don't have (and we all know it is impossible to get) a MD CCW permit. This is akin to telling residents of RI they can't drive in TX because they don't drive in a big state. I am so ready to leave the Democratic Peoples Republic of Maryland! Also, I found out the PA AG that came up with this BS law in in jail for 18 months for other bad decisions she made.
There are still a few non-resident permits that the Inmate General was unable to mess with. Texas and New Hampshire come to mind, although I believe the training for a Texas permit has to be taken in Texas so that might be somewhat inconvenient. I think that there might be a few Marylanders who have obtained a NH non-resident but I don't know off the top of my head exactly what that entails.
With the recent changes in Maryland law concerning medical marijuana, see MD Code, Health - General, § 13-3304 et seq., and the push to legalize the use of marijuana in Maryland, a recurring issue is how such marijuana use would affect your Second Amendment rights. The short answer is that it may well act to abrogate those rights by (1) barring a FFL from selling a firearm to such a user and (2), by making such a user a prohibited person under federal law.