[dreamkilla22]

well i already have an e grip for my gun and a better barrel its 20 inch barrel what other ups can i get i also have the spring kit for my gun

[jmoutlaw]

Sell that 20 inch and get like a 14. After about 16 inches you are just wasting air. Then get a better hopper. They make the rip clip for the bt4 I think. Maybe a stock too.

[lego]

also upgrade the egrip with the rampage board for more choice of fire rates.

[BRIK]

It all depends on what your trying to achieve...

Here is what I did to my BT4...


Polished internals
Magazine expansion chamber
Rip Clip w/X7 low profile hopper
E grip w/APE Board
6 Position CAR stock
Cheek Saddle
F.O.G front shroud w/ twin rails
Stubby Front Grip
twin rail sight riser w/45* offset
30mm red dot sight
Drop Forward (to get ASA away from my large paws)
14" Progressive Barrel (Recently upgraded to 14" APEX ready Lapco Bigshot w/ APEX tip)

I've seen the BT4 done up in many many configurations...Personally, I suggest the RIP CLIP, by far its the best upgrade for the BT4...along with the E GRIP...

[Jarz]

I don't have E-Grip, but I use an Invert Halo 2 loader, a 14" CP barrel, and I'm thinking of buying a double trigger, not the electric one, just the manuel one.