BT-4 with Stock Internals on HPA
A5 with Stock Internals on HPA
1) Angel1, Stiffi Switch Kit, Halo B Hopper with Victory Board, Carbon Fibre HPA
2) Proto SLG 08, Deathstix 14" Series 1 Barrel, CP Clamping Feed Neck, Velocity Jr Hopper with Virtue Board, Carbon Fibre HPA
3) BT4 Combat, Deathstix 14" Series 2 Barrel, Zero Kick Hammer, BT Spring Kit (Silver), BT Double Trigger, Viewloader Revolution Hopper, Carbon Fibre HPA
Well machined, perfect fit, works as advertised, better groupings on rapid fire.
Mine didn't include spring kit, had to buy my own (I'm in Australia)
Mine performs as advertised. Clearly has reduced kick. This improves accuracy in rapid fire groupings. No real improvement in single shots.
Installed easily, instructions from TechT website were OK. Diagrams would have been nicer but I referenced my BT manual in conjunction with TechT instructions.
It was a perfect fit. Fine tuning was needed to ascertain which spring from the BT Spring Kit to use. The Red Spring (Strongest) resulted in great performance when shooting slowly. However 2 very quick trigger pulls would cause marker to shoot first ball then uncock, leaking air.
Switching to the Silver Spring gave me great performance with no problems and I was able to reach 300 fps. Velocity variation was no different to the stock hammer. I shot a box of paint over the course of a days play.
All in all, I'm happy with the results, it improved my ability to hit small targets of opportunity. A quick burst to an exposed foot, marker, head was usually hit before it could be pulled back in to cover. Previously if the first shot missed, the others were unlikely to hit (due to kick) prior to the target being alerted and moving.
Don't expect miracles but I found that it did as advertised, significantly reduced kick.