1.5 would still be a little tight, I have a Shocker that I run on Co2 with a .68 and it only allows me to fire 7 pots (of good powered shots) but that is ok as a front player but that is using co2 and you tend to get a bit more over air. The upgrade for the AIR is available from WDP and any certified Angel Tech outlets, it allows you to use the AIR at lower output pressures than the usual versions (all new AIRs come with this upgrade, you can tell just by looking at the regulator it has a dome on the front before it was flush) cost wise? dunno call WDP and ask, I was going to have it done at the World Cup but then as I don't need the lower output I didn't do it.