Hello, There are several clubs in that area that host rifle, pistol & shotgun events, some a 3 gun matches where you shoot all 3 guns in the match. Topton is close to allentown, there is a match almost every weekend and they have some great 3 gun events. Ontelaunee just north of Topton has almost every discipline possible including all the olympic style events. Palmyra near Hershey has the
PSA SHOOTOUT every April and they will have 350+ shooters with over 650 guns shooting all reactive steel targets. Old Bridge in north jersey, Central Jersey club in the middle both have a list of pistol events.
You should visit the forums at
Brian Enos - Competition Shooting Books, Slide-Glide, DVDs & Reloading and click on the 3 gun section and check the rifle page. The gun of choice is the AR15 set up for 3 gun practical shooting events, that will be low power optics, bipod, sling and a few other cool details. That will probably be what you are looking for, with all the correct items to comply with the peoples republic of NJ.
good luck, Karl @ GT Targets or Karl CSX2498