Umarex Steel-Storm .177 Caliber BB Gun Air Pistol My new favorite bb pistol
Update: I've had this 2 weeks and shot over 2000 rounds thru it without so much as a hiccup. So far it's been very reliable and a great platform for mods.
Pierce the co2 cartridges fully and run pellgunoil or silicone oil thru it liberally and it will not disappoint. So far my mods are foregrip w/bipod, reflex sight, removable 4-position stock, and I found an mp7 holster that's pretty dope. All these were bought on Amazon except for the stock which was an eBay takeoff from a broken airsoft mp7.
6 round bursts are no joke. The rate of fire is very high for those 6 quick shots. This thing is actually really loud, but apparently pvc pipe silencers are very easy to make and highly effective... So I've heard.