SPEED Airsoft M4/M16 HPA Tunable Trigger (Color: Silver / Blade)

"i think you should buy this if you want to shoot this put this on my polarstar shoots very good recommend this to anyone

"This thing is AWESOME when you get it dialed in just right! Night and day difference from the stock trigger on my Krytac Trident MKII SPR with a Polarstar Jack installed. It did require very minor fitment to move smoothly and freely in the stock Krytac gearbox, I just had to slightly ream out one of the holes where the trigger's cross pin fits in the gearbox. After I dialed the trigger in, I shaved the safety lever a little so I could still use the safety while having the trigger essentially pulled most of the way.

Here's how I adjusted my trigger once installed:

Connect just the battery to the FCU. Don't connect air!

Remove the screws and put a tiny amount of blue loctite on them. It'll take a little time to cure so get right to adjusting.

Back the take up screw (front) out and screw in the over travel screw (rear) until it stops. Back the over travel screw out while gently pulling the trigger just until the gun fires (solenoid click). Back it out another quarter turn and test the trigger to make sure it fires every time. You can fine tune from there by turning the screw back in in tiny increments to eliminate more over travel while maintaining reliability.

Then without your finger on the trigger, turn the take up screw in just until the gun fires, and then back it out a quarter turn. Make sure it fires every time you pull the trigger. Again, very fine adjustments.

At this point, you're pretty well dialed in. You can fine tune both screws, a tiny fraction of a turn goes a long way.

I shaved my safety lever a little so I could still use the safety with the trigger dialed in the way I have it. At first the safety would not engage.

Overall, COMPLETELY worth the effort of fitting, installing and tuning. I can rip semi auto shots off very quickly, one guy thought I was using full auto!

"Got an M4 and HPA. These are the perfect complement. This is our third one. Just loctite after it is where you want it. docB