Ooh, 7 pin... should be fun.

No idea what kind of security pins are in these, but if they use them around the barracks I'd assume there are some spools or maybe even serrated pins in there.
Personally, when I come up against a lock I've never seen before, I treat every pin like a security pin and make sure to lift the pins (especially the ones towards the back) as high as I can when pushing them up. When I lift a pin all the way up and it doesn't click, I move to the next one - and if it does seem to set, I always let off on the tension just a tiny bit and keep lifting to see what happens. With a 7 pin cylinder you'll be able to rake it into false set very easily to get you started, so try that. I usually scrub over the pins while using light, pulsating tension until I get a nice big rotation then SPP from there. It'll take you a while to figure it out, but you'll definately get it. You may not be able to get your hands on the key, but if you can get a quick look at it and take a mental note of the bitting it'll help you out immensely. It's kinda cheating, but do it if you really need to.
Best of luck!