Layusn1 - I'm right down the road from the locations you mentioned - I can walk to Jeffers Hill in about 15 minutes. (ok 20, but I'm a big boy, gimme a break!)
And yea, you can bring what you've got. Like Spot & Norton said, we're not nearly as bad as some of these other folks want to have you believe. We do have waiting periods, and one-gun a month, but so what?
And as far as On Target goes, I'm a member as well, so if you'd like to check it out sometime I'd be glad to have ya along. They are pricey, but Norton nailed it - they're super convenient. The next closest place that I know of to shoot is Hap Baker in Westminster, and that's a little bit of a hike to shoot at as often as one would like. Still a great place though. And if you do get a 9mm AR to shoot at OT, you gotta let me shoot it a little! I've never shot one (.223 or pistol caliber) and I've been dying to try.
Oreo - Class III refers to full-auto or other NFA stuff (suppressors, short-barreled rifles and shotguns, and AOW's (any other weapons)) Some states consider them a no-no, but Maryland is one of the states where as long as you can go through the hoops like everyone else who owns them, you're good to go. Kinda flies in the face of the picture some of the commenters here paint of the gun rights situation in MD, huh?