Welcome to the Alamo City.
Shops:
Nagel's (San Pedro between Basse and Oblate) has some nice stuff, but are proud of their stuff too. Open until 6pm, though not on Sunday.
Powderhorn (Loop 410 between Hwy 90 and Marbach) had nice stuff. I hadn't been there in a while, but they normally had a lot of BM and Armalites to look at. I think they close at 5pm, and not open on Sunday or Monday.
There may be a couple more shops around that I haven't been to, as well as pawn shops.
Two ranges I normally shoot at are the Bracken Range (Nacogdoches Rd, north of Loop 1604, about 2 miles), Cedar Ridge (US281 North to FM 1863, 11 miles (towards New Braunfels)), and A Place to Shoot (Morsund Ave, via Loop 410, in the direction of Pleasanton.
Bracken has 50/100 lines, one silhouette range, benches for pistol (3, 7, 10 yds, IIRC), and shotgun. Nice folks, clean, but the benches are a little shaky. Cost is $3 a gun, $3 a target set (four bulls on a frame)--silhouette is $6. They close at 7pm during the summer week, but 6pm on the weekend.
Cedar Ridge is a little far out, but decent, and relatively quiet. $10 gets you in the door until sundown (aka 7pm), and the max distance is 100 yd. The benches are concrete and very stable, but bring your own stool, or if you're tall like me, you won't be very comfortable. You move your own targets (and can bring your own), and you'll need to make absolutely 150% sure you are striking the paper at a full 90 degrees, and that the bullets are impacting the REAR BERM ONLY at a true 90 degrees. Let's just say they want to be safe. Pistols and shotguns are allowed, but to shoot steel requires you to join some local club that shoots out there.
A Place to Shoot is a little far to drive, and is sometimes crowded (pistol and shotgun). You can shoot trap and skeet there; pistols are in stalls (like you see in the movies), rifle is from bench only, with plenty of lines from 100 to 200 yds. I have fired prone out there before, but it required me to be forward of the firing line, which is ONLY OK when no one else is shooting. They have a small gunshop there for those essentials you forgot to bring. I don't like the fact the only 9mm ball they have is S&B, and pay like $12 a box of 50. I think it is $6 or $7 for the first gun, and then $3 each additional gun. The wind blows through the pistol stalls pretty good, so it makes slowfire practice a little difficult. They stay open until 6pm, I think.
There are other ranges, like the Bullethole and Blackhawk, but they are even farther out of town. Bullethole used to rent CLASS III (H&K MP5A3 and MP5SD3) for $100 for 5 mags, but I don't know if they still do. They have a 300 yard line, but the range is an impact range (instead of having a backstop).
Head over to the Texas Hometown forum, and search for the next Texas Tactical Match, which is this Sunday, outside of Austin. It's good fun, and you get to see what your AR can do!
-Zmeja