Seems im bugged on this quest, got them to the shooting range and can't do anything, can't talk to any of them or bugger all.
Any way round this?

wait there a while and make sure they all show up?

Same thing happened to me - everyone would gather at the range and wouldn't do anything. I ended up having to wait a few in-game days and then come back - they'll be waiting at the range, and hopefully their dialogue will begin.

talk to the chick maggs again. when they're all lined up at the range she'll start dialogue. you cant complete the quest without 50 guns and 45 explosives tho

I think his issue is that they're all lined up, and Mags won't initiate dialogue. The same thing happened to me, and I'm not sure what i did to fix it. Just come back to her in a day or two?

Cheers for info, luckily i had a save 20 minutes before and just re-did the quest and it worked :s