A5 polished internals
JCS Red Hot power tube
Delrin front bolt
Opsgear 416 body
Opsgear 14" M4 barrel
BT M4 adjustable stock
Metadyne M4 hide-away mag
Techt Lightning Rod
Trinity squishy paddles
E-grip with Rampage board
UTG folding sights
Light weight, less kick than the stock hammer
Out of the package the hammer is obviously built with an emphasis on quality. The alloy used is extremely solid, so solid in fact that I broke a titanium-carbide drill bit attempting to enlarge the hole in the top of the bolt for the linkage arm (yes, the hole was too small), which was the first problem.
The second problem became apparent when I tried to slide the bolt into the back of the A5. It would not slide into the receiver and after getting it jammed part way in I had to split the receiver halves to get the bolt back out. I spent an entire hour using a file to reduce the diameter of the bolt before it would fit into the A5 without jamming anywhere in it's travel during cycling.
Though I believe this is more likely a case of Tippmann not producing A5's with exacting tolerances, I think TechT should have taken the time to do some research to ensure that this bolt would actually fit all of the markers it is compatible with. Once the problems were dealt with, I found the bolt does work well with the stock spring, I had no trouble getting the velocity to the field limit of 280 fps, and it does reduce the kick significantly as advertised.
Aside from the reduction in recoil, this bolt didn't do anything the stock bolt doesn't, and I never had a problem with the fit or operation of the stock bolt.
I would not recommend this bolt simply because it's a gamble whether or not it'll fit properly in your marker, and in my opinion the reduced recoil the hammer provides isn't worth the cost or the headache.