Yeah, that Light/BEWARE is pretty nice. Accelerated Coils Light/BEWARE is pretty deadly. Red Dot ORS adds a bit of Range, Hip Fire tightens the spread and Accelerated Coils maxes the charge rate. It's probably better to spend your motes on rerolling some of the other Iron Banner weapons or buying Exotic engrams... a good perk for PvE is Performance Bonus. With it, every enemy killed has a 25% chance to return 5 rounds to the reserve ammo. If you make sure you get a kill with every 1-2 rounds, that's basically infinite ammo unless you are unlucky. Since you need a Solar, I'd say buy a 2nd one and reroll it for Performance Bonus if you have some spare motes.