BT 4 Assault
16 inch barrel
RIS rails for either tactical light bipod or laser dot
BT expansion chamber (mag style)
A5 HE selector switch electronic trigger (modded to fit on BT 4 its simple)
BT RIP CLIP
tactical 1 point sling
The style looks mean
Co2 liquid expands in mag not gun
internal o-rings extremely hard to find
Hex screw strips holding mag
I purchased this 2 yrs ago, to give my BT assault a more realistic look. At first I loved this, there was no problems at all with it.... Now, BT has apparently stopped producing these and do not have parts available, areas that are a problem for me are the O-ring internals, the one broke on me this may 24 weekend, and I haven't been able to get a replacement oring for it. I have tried everything to make it work, nothing so far has worked, the problem is there is an elbow screw that goes into your expansion chamber, then you have a pipe that connects to the elbow, and has another elbow at the other end where the mag pushes into locking with a o-ring. when those special orings go, you can't just go to the hardware store it seems to pick them up. So that is why has got me on here, to warn people that they look good but BT doesn't seem to care much about them anymore.
The other drawback is the screw that locks the mag into the mag chamber, the hex screw first off is a different size then the other hex screws on your gun, its smaller so you then have to have the 2 different allen keys with you, and that screw is stripped for my now, so it just spins in place. (put tape on the mag its self where it touches the metal, then it wont rattle in the bushes when you walk)
The nice thing about this is it is a mean looking add on to the gun, it adds alot of weight to your gun though its ceramic and metal, but it does save your interals from liquid CO2.
I like it, and I will eventually find the right o-ring and get it fixed, its a decent buy, too expensive though, I didn't like having to pay 120 bucks for it, that was half the price of my gun nearly.... but I still like it,
Its good, it saves your internals, looks mean, just remember you don't get anymore support from BT, and you will need to search out new orings from somewhere out there, it will build your arm muscles