B3 gas ram - possible project

[wlfpck]

I've seen the B3 underlevers for sale on Amazon for pretty cheap. I was wondering if anyone had the specs on the piston diameter and stroke length.

I figure I could pop the gun open. Cut the spring guide. Drill a dimple for setting a n-forced or Moeller gas piston in. Then seal the whole thing. Only thing I need is the stroke length. Or if someone knows what size gas ram to use. I figure this could be a good consistent small underlever rifle.

Figure this would be a great learning gun to start with so I don't destroy my trail xl taking it apart.

[B67]

The thing with a B3 is that they are relatively low powered and react well to polish and general tuning...I have one that I love. Take a Crosman and work with it.  It will be cheaper and more rewarding. I have a Crosman Titan NP that is deadly...

[A.K.A. Tommy Boy]

This is Good.  I might try this.     I'll be watching the followup on this post.    Best Regards   -   Tom

[ricksplace]

I own a Crosman springer, a Crosman Nitro Piston (gasram), and a Chinese B3. Of the three, the crosman nitro piston is the easiest to work on. Parts are cheap and available. Crosman nitro piston refurbs are widely available for about the same price as a B3. Buy one to learn on. After your first lube-tune, you will have a sweet shooter and the know-how to tune your benji. Then you will have two sweet shooters... and you're hooked.

[shadow]

In the past here at GTA many of the early members jumped on the B3 wagon myself included and were tweaking them to their breaking strength and several B3's were touching the 800fps range which is asking a lot from a B3 hehe. The B3 has weak points to take a close look at before placing a gas ram in them and the main one is the trigger design which is known and have experienced myself not to hold when placed under the stress of a stronger spring or possibly a gas ram. Special care must be taken when addressing the trigger part's polishing wise and some triggers and sears from the B3's were useless and dangerous out of the box. It sounds like a great mod to try but please be careful and keep us updated on your results. Ed

[Scotchmo]

...The B3 has weak points to take a close look at before placing a gas ram in them and the main one is the trigger design which is known and have experienced myself not to hold when placed under the stress of a stronger spring or possibly a gas ram....

The force of a gas spring is much less progressive than a typical wire spring. That's makes it possible to have a higher average force with less load on the sear. It is possible to gain power while reducing trigger loads.

A small power increase with a gas spring can work OK and still be as safe, or safer, than the original spring. Keep the compressed load near or below the compressed load of the original wire spring, and you should be fine.

A large power increase over stock won't usually work well.

[longhunter]

the standard crosman ram will fit. I only know this, because I considered doing the same thing, once. then, I asked myself, WHY??? never did convert the bugger to gas. it shoots too nice, just the way it is.

[Onebaddj]

I did it with a gas ram out of my gamo hunter several years ago. Pretty fun and easy process. I had to cut some of the length off the gas rams shaft to get it to fit and be able to cock. Like shadow said too much pressure on the sear and it will not hold making it very dangerous and un predictable. Once they are set up correctly its just another thing on the list that you can say you did. They are fun little guns to tinker with and if you destroy it your not out very much money. Thats the best part.

[Mr. Panther]

A stock B3 spring demenions I found were 36 coils, .117 coil wire size, 9.3 spring length, .490 I.D and .737 O.D diameters for the spring. Hope this helps.