You can't
buy a magazine over 20 rounds here, but you can own them, use them, and import them for personal use. Just make a short drive to a neighboring state (Pretty much every place in Maryland is within 30 miles of another state), buy all the 30 rounders you want, and bring 'em back. Perfectly legal. Just don't pick up any for your friends.
No "assualt weapon ban". Flash hiders, bayo lugs, pistol-grip stocks are fine.
There is that list of banned "assault pistols".
Machine guns are OK also. Just meet federal requirements, and pay an extra $10 each-and-every-year to the leeches in Annapolis.
Of course no silly "hollow point ammunition ban" such as New Jersey has.
Handguns have to be on a list of approved models. This is the so called "Saturday Night Special" ban from 20 years ago. Most seem to be "approved" however, so it's not quite as bad as it sounds. High Points and Kel-Tec P380s are ok, for instance. Anyway, here's a link to the list:
http://www.mdsp.org/services/handgun.asp
Handguns and certain listed self-loading rifles (that is, so called "assault rifles") are treated as "restricted firearms". These require a Maryland State Police ("MSP") background check and a 7 day waiting period. After seven days, the store can legally release the weapon even if they have not heard back from the MSP. In practice, some stores will release it, some won't, but I think The MSP usually doesn't drag their feet too badly. One of the bigger dealers recently told me he usually gets the "NOT DISAPPROVED" (insulting, huh?) response in two days or so.
AR 15 HBARs are NOT restricted. You can buy a Bushmaster Heavy Barrel Carbine, or any other HBAR "cash and carry", just like any other rifle.
There's a limit of 12 restricted firearms per year, pretty much one-per-month, but supposedly you can get more in a single month if there's a special sale price or something, as long as you don't exceed 12 per year.
These restrictions DO NOT APPLY to Registered Collectors. You can buy as many "restricted" firearms as you want, with no waiting period, if you file a simple form with the MSP registering yourself as a collector. Some of us don't feel like registering ourselves, but it's less onerous than the self-registration every CCW permit holder does outside of Alaska and New Hampshire.
Handguns are NOT registered (but I suspect "they" have a list), and you don't need a permit to buy one as is required in some states (viz North Carolina). ("Not fair!" someone cries out. That requirement doesn't apply to Tarheels with a CCW!" And Maryland's restrictions are waived for anyone who sends in this one-time form:
http://www.mdsp.org/services/handgun.asp
So Maryland Gun Laws Suck, but not as badly as most seem to think. Not as bad as New Jersey or Massachussets, and I am NOT bashing any other state here, or even Britain or Germany, for that matter. I do feel a bit like Uncle Tom saying all this, though. "Ol' Massa don" whip
me so bad. Massa over at the nex' Plantation, he whip his slaves twice as bad!"
Perhaps the worst thing here: it is nearly impossible to get a Concealed Carry Permit. Maryland is the textbook example of what's wrong with "May issue", as opposed to "Shall Issue." You have to have a proven need to carry, such as being a jeweler who regularly carries bags of diamonds around. Even then, you have to fight, fight, fight the MSP through multiple rejections and appeals, before being grudgingly granted a limited permit. (I understand this doesn't apply if you make large campaign contributions to the right politicians.)
But hey, pepper spray is legal, unlike some places.
But really, the WORST thing about Maryland is NOT the gun laws, but the general political climate. Maryland is a Corrupt, One Party (guess which party!) State. Our taxes are outrageous, and they keep going up. This is a very prosperous state, and there is a lot of work here, but it is a Cesspool of Liberalism. More and more people are fleeing, and many live just across the State Line and put up with long commutes to Maryland jobs.
One of the best things about Maryland is the State Line is never more than 30 miles away. (Except for I think one small spot in the middle of the Chesapeake Bay.)
Check out this site for more information:
http://www.mdshooters.com/