Today I finished my secondary AR-15. It still needs to be test fired and zeroed. I installed a Sylvan folding stock adapter and remounted my EOTECH 512 that was on my Smith and Wesson MP15-22. The stock adapter is very solid. This rifle is a carbine but has the H.B.(heavy barrel) 1/9 twist. This thing weighs more than it needs to. It has a A -frame fixed front post and a Magpul b.u.i.s. in the rear. A Magpul front hand guard and an ATI rear stock with an adjustable cheek piece. The hand grip has finger grooves and is sized to give a longer finger reach. It has an ambi safety. I have thoroughly cleaned it. I may add a Frank Procter sling. Any ideas on a trigger upgrade?