I just finished my gas rammed B3!

[stilkikin]

   Ok I picked this B3 up off CL for 20 bucks. I was unhappy with the way it performed. No power or accuracy. It also sounded like a freight train on gravel when being cocked or fired. I took it apart and found that the plastic piece that holds the leather seal was shattered in a million pieces. I decided it was time to build this thing the right way.
   First thing I did was lop off the front sight and cut the barrel 3 inches. Then I crowned and polished it. Then I installed the MB off a G1 extreme. From there I honed the compression cylinder and made a new breech seal from a 3/8" tapered hard rubber washer. I installed a new leather seal and plastic adapter. I'm still waiting on the apex seal adapter from Target Tune India BTW. I recommend nobody order from there. It's been 3 weeks and they still have not even filled the order, much less shipped it. (Ripoff) I deburred the outside of the cone shaped loading port on the breech end of the barrel because it was ripping my breech seal to shreds, then put a second seal in. I then chamfered the ID of the breech end of the barrel to make loading and pellet seating easier. Then I moved on to the horrible trigger. It has a fake two stage set up. The first stage is built in to the trigger itself. It has a spring loaded pivot the incorporates about 1/4" to 5/16" of creep. I've yet to address that. I did a complete polish job on the trigger, sear and catch on the piston. It did wonders for the pull weight on this thing. It now breaks predictably at less than a pound. With the way it is now I am not satisfied. The "first" stage has more pull weight than the second. This trigger is a good candidate for a single stage. I will be drilling and press fitting a pin through the trigger blade with it pulled back all the way at end of the "first" stage to hold it in place and eliminate the fake first stage. It will place the trigger blade in a more comfy spot to. I will end up with a crisp, one pound, single stage trigger. Then I turned my attention to the cocking levers. There are two stacked side by side and they move independently of one another causing the compression cylinder to rotate a few degrees in the receiver tube with each stroke then returning to the same position. I remedied this by filing the burs flat on the compression cylinder cocking slot. Then I drilled and press fitted a pin through both cocking levers to keep them moving in unison. I filed the catch on the end of them back down to where they were flat and not worn independently. Now the cylinder stays straight in the receiver tube and I still have enough pressure to keep the breech sealed. After this I put in the gas ram. I had to cut off the spring guide 1/16" in front of the cross bolt. I used a miter saw to keep it straight. I had to tape it to a 2" x 3/4" piece of oak to keep it in position against the fence and not move while cutting. I found an old quick connect from a hydraulic fitting that went on the back end of the Titan's ram perfectly. I cut it down to 1/2" and installed it on the back of the ram. I wrapped three layers of electrical tape around it to dampen it and fit it to the bore. Ghetto but effective. Gene's GRS kit was robbed from my Titan too. It took a little bit of shaping by putting a taper on the front of it and taking about .5 mm off the OD but it works perfect for keeping the ram centered. For the front of the ram where it contacts the piston I had to do nothing. The tapped screw hole for the seal is enough the keep the ram's rod centered in the piston. The gun now shoots with authority and is extremely smooth. Nothing like factory!
   I refinished the stock to. I stripped it using aircraft stripper. Then I did some minor shaping on the grip to make it more ergonomic for me. I made a 3/4" spacer out of red oak to increase the length of pull and whipped up a GTA logo for the cheek rest. I then sprayed it with bedliner and two coats of a catylized clear I use for porcelain and fiberglass refinishing.
   I love this shooter now. I'm going to be breaking it in today. I'm going to try and get 500 shots through it to break in the seal and test the ram. I've shot it a couple times last night when I finished up but now it's time for the real test. I threw a Center Point 4x32 on it for the mean time. I have plans for a Leapers 3-9 bugbuster in the near future. Anyways here's some pics.

Before.


Stripping the stock.




Completion.






Enjoy!
       

[mav72]

Good job! The spacer used to increase the length of pull sets off the look nicely... What method did you you use to attach it? I'm planning on doing the same thing on one of my guns but I'm not sure which way to go on it......

[stilkikin]

I drilled pilot holes through it and used longer screws on the butt-plate.

[bradyman1]

Looks great. Do you know how fast it is shooting? Is the shot cycle comparable to your Titan?

[Fisherdude]

This is a really great project!  I am very interested in knowing the muzzle velocity of the final product.

[stilkikin]

 The Titan is .22 so it's an apples to oranges thing. My guess is it's in the 700 -750 range. Maybe more. The B3's compression cylinder volume does not really support a high velocity gun. To make a comparison I gave the gas piston as much room for stroke as possible and I still have 1 5/8" preload on it. If there was more cylinder volume it would be better. That's why I wanted to go with the TTI piston adapter and an Apex seal. I would gain close to 3/8" of headspace. I don't have a chrony. The shot cycle is as smooth as silk now and the trigger problem is fixed too. I just had a little bit of lube on the sear to piston contact point. After shooting it 300+ times today it is settling down very nicely.

[z28rod]

Thats one heak of a b3 man !!!! Great job, I loved your detailed desciption of your rebuild. I sure bet she shoots great, I bet Mike Melick will want to read this post. I think this is the first Nitro Piston in a b3 Ive ever read about.

[stilkikin]

It's the second I know of. Another member here did it too. I think Mike might have at one time too cause he advised against it because of unreliability issues. I was leary of the amount of pressure the GP would put on the sear to piston contact point, I thought it would make it dangerous but it has not misfired once all day. The first thing I did was do a bump test with it cocked and loaded. I hit it from all angles possible with my palm, hard, and I couldn't get it to misfire. That was with lube on the contact points too, it definitely won't do it dry.

[redone1992]

Looks great

[Onebaddj]

Awesome job! These less expensive guns make great projects because you can do anything and if you kill it well your only out $30 but when it works man you got bragging rights. I put the np out of my gamo hunter in my b-3 and am getting low 700's out of mine with 6.9 gr rws and 680's with 7.33 gr jsb pellets. Its not hard to convert them either. Great job on your stock also. Cant wait to see the numbers on yours.

[dk1677]

Very nice job!

[venxxxxx]

where did you buy the gas ram ? Im looking to convert my old 6yrs old B3 with a broken spring to a nitro spring.
thanks

[Mpac]

You might email or pm him since he hasn't been active 12/02/12.Might get quicker response.

[BenjiHunter]

Great job. It looks awesome!

[Onebaddj]

Venxxx, if you search for nitro piston or gas ram here there are a few threads with all the info of where to order gas rams and the different weights and color codes. Lots of info on them on here.