"Not only does this add the look and feel of an M-16/M-4 magazine it also functions as an expansion chamber. Expansion chambers improve the efficiency of your air source and allow room to expand into a gas instead of potentially running liquid co2 through your marker. With the magazine expansion chamber, looks are certainly more than skin deep. " --www.btpaintball.com
The BT Paintball Design Magazine Expansion Chamber is newer, so it should be commonly available, both new and used.
BT-4 Iron horse
Ricochet AK loader
SpecOpsbrand Mamba fighting sling
BT magazine expansion chamber
Weight ( doesn't bother me though)
If you play with CO2, and you can't afford a regulator, an expansion chamber is a mid level fix to the problem of freezing and spiking. If you are a milsim junkie like I am, a magazine is a no brainer upgrade. The folks at BT Paintball were nice enough to create a magazine upgrade that features a three chamber expansion.
The first thing I noticed when turning my remote on was it took a couple seconds for the chamber to fill. This seems to be a good sign to me, since the point is to allow liquid CO2 to expand and become gas before it gets to the marker.
This may have been luck but I didn't have a misfeed all day(nothing to do with the x chamber but still noteworthy), nor did my marker freeze up during rapid fire strings. I also noticed that I had more consistent groupings than prior to installation.
Speaking of installation, the magazine expansion chamber kit comes with everything you need, and all the threaded parts are already threadlock coated. Literally all you needed to install was the hex wrenches they provided and an open end wrench for the fittings.
I think it took me less than ten minutes to take my marker apart, remove the old hose from the power tube, place the new brass assembly in, put the magazine on, and thread the new hose to the asa.
The magazine and magwell are two separate pieces, and there is an o ring that actually seats the magazine into the adapter. it is secured by one bolt.
There are only a couple bad points about the magazine expansion chamber. The first is it is very heavy, I would say close to three pounds installed, and thus makes your marker very muzzle heavy. The second is that you have to remove the magwell and magazine every time you want to open your receiver, which means you have to disassemble and remove the magwell. This is no biggie, but it is one hex and two thumbscrews more than normal. Third, the new hose is a bit too long, so it bows up a little instead of running straight, which means you might have to put some effort into getting it back on.
I don't personally think any of this is a big deal, I think it looks terrific and does it's job.
If you don't mind the weight, and aren't read to switch to HP yet, get this.
8 out of 10
Last edited on Tuesday, April 10th, 2007 at 3:37 pm PST
Magazine Expansion Chamber
14" J&J Ceramic Barrel
BT-4 Car Stock with 6 positions
One Crappy Hopper
My apologies if my review is worded weird or weak and stuff, but I am a noob at paintball and paintball lingo.
So I purchased this piece for my BT4 Combat. And I have noticed a bit more improvement on the overall performance of the gun. I was told by some people in paintball stores that this should be my first upgrade to my gun, not just for looks but for added CO2 performance. I have only had a chance to use it once and found that my CO2 didn't run out as quickly as well as no freezing or liquid issues.
It is a heavy piece and does ad considerable front end weight, so adding a stock to the back of the gun will, help alleviate some of the weight by letting you cradle the gun into your shoulder. Specially if you like to play for hours on end.
Installation was a bit of a pain in the ass, but that was just because I haven't had any experience taking a gun apart. But once I started and followed the BT4 instruction manual and the magazine manual, it was pretty easy, took me like a 1/2 hour. Also nice that the pieces had the threading tape already on them. I still added a bit of threading glue as well, just to be sure of a good seal.
My really only complaint if any is the price $125 cdn is a bit steep for such a small piece, considering my gun cost only $150. But I guess that comes with territory of playing any type of game or sport. The better the equipment and upgrades the more you pay.
If you into the looks aspect and for a little better CO2 efficiency and you have some extra cash to burning a hole in your pocket, than I say hey go for it.
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