Ditto. Most units hire internally. These jobs aren't well advertised, even within the unit if you can imagine that. Coming from AD, while beneficial in terms of qualification and experience, is not an entitlement to a full time position. If getting passed over for an ART/AGR jobs by a younger guy with less quals than you but with more longevity at the unit is going to cause you heartburn, the guard/reserve is not for you.
Generally speaking, most of the positions open up due to personnel attrition and unit mission expansion. Little of either happening at any given time unfortunately. So like the previous poster said, it's all about luck, timing, a lot of patience, and a general consensus at the unit that you're not a douchebag (regardless of the fact we all know some ART f%k up/douche) for these gigs. Bumming is really the conventional way to vie for a full time slot, and this takes time and presents an opportunity cost. You could go pursue a civi job and lose out on the exposure being at the unit 24/7 for the sake of the ART contention, or you could bum and struggle through the paycut, particularly if coming off the AD teet. It all depends on how much work the unit can provide you of course, some units you can do alright on mandays, some unit are slim on money and you just can't make rent at the end of the month on bum status. So that affects your options. Good luck, I'd say don't put the cart before the horse, concentrate on finding the right unit, research your options with said unit and what the future holds for in the context of the feasibility of a full time slot becoming available to you in the time frame that you can stomach, and devise a strategy of putting in your time. I'm a young guy with no kids and I can tell ya I don't expect to get an offer for full time slot for at least 3 more years, which is kinda scary and a tough sell for my soon-to-be-spouse, but it suits me and bumming beats (right now) 90% of the jobs I could be doing in town or commuting for anyways, but that gives ya an idea of how long people sometimes have to wait for a slot to become available; this may or may not be compatible with your needs/desires. Again best wishes on your search.