Yeah, there is always a job for gun/ammo runners
The only issue is that you need to move a lot of product to make money. I mean, it is probably about a 10% profit, but for things that are only a few $k, you need to really be selling a lot.
I'd need to check my exact numbers, but so far I've made about 30 to 40% margins running faction missiles and ammo in high-sec. I haven't even bothered with low or null-space yet.