James git me hooked and I want one. Who can solder and desolder? Who can "braze for praise?" Somebody, anybody this is your mission. Or at least a .25 barrel. While I'm thinking, let me see if I have a .25 barrel laying around. Yeah, I know how hard it is so don't start all of the whining naysayers

Dafatman31

all you really need to do is create a steel or brass (anything you can solder) riser that matches the circumferance of the pump tube to lift the breach/barrel up 5/16 .. 3/8  inch or so. recreate the same curve on top.

Match and drill the holes from the tube and breach.

Unsolder the barrel. clean all the solder out of that hole. Machine yer barrel blank to fit the hole. fit must be ooooh sooo precise. Create the  porting using the orginal barrel as a guide. Decision time: you could solder it back in ala the original, or drill 3 holes (say .050) ahead of the loading port at the 8,12, and 4 oclock positions (or 120 degrees apart). small thin oring to seal.

The riser allows you to shroud the thing. You will need a barrel band for at least the muzzle. If you shroud it, you can put a bushing in the shroud to help center the barrel, and take some of the stress off the breah.

Downside? now the breach carries all the stress of the mechanical joint. the front barel band will help some. A center band wouldnt be all that hard to make and install. If you use something like Lundy's breach mounts, the scope adds to the aforementioned stress to yer joint

I have no way to machine steel or brass to the levels of precision necessary or we'd discussion build issues instead of bench racing it.

I would be willing to donate a 39x pump tube and breach. and some drawings that explain it more if some one can come up with the necessary machining skills, tooling and the other parts.

Aint afraid of the solder... just need some other bits and tools

dr_subsonic's pneumatic research lab

the Lunatic Fringe of American Airgunning
Southwest Montana's headquarters for Airgunning Supremacy
Proud Sponsor of team_subsonic

...directly to the brass pump tube with the associated difficulty of getting a strong bond (due to such factors as the very different coefficients of thermal expansion of brass vs steel, lesser solder "wet-ability" of steel, etc.), what about soldering a large ID brass shroud on instead? The easy to solder brass shroud would then...

1. Establish a strong solder bond that would help support the breech and reinforce the tube.
2. Contain and support the (maybe even swappable for multiple calibers) barrel.
3. Perhaps be enough longer than the barrel to hold a few baffles in front of the muzzle and so do that voodoo that they (baffeled shrouds) do so well.

Steve

excellent idea. get it the same OD as the pump tube, remove paint on pump tube and polish the brass on both for that extra bling. with baffles the perfect short range back yard .30 pest remover. John

(which appears to be more common lately )

I'm a\saying solder on a riser platform, solder the breach to that, but modify a slip in barrel held by sets crews (sealing it is still a design issue).

Riser plate, and necessary rework of the front barrel band, will allow a shroud of say carbon fibre or thin walled aluminum.

Barrel,as you say is likely to be steel, and will not be soldered.

But a soldered on "band", say 1/2 down, with an ID of what the CF shroud's OD is a good idea.

 

dr_subsonic's pneumatic research lab

the Lunatic Fringe of American Airgunning
Southwest Montana's headquarters for Airgunning Supremacy
Proud Sponsor of team_subsonic

...to accommodate a larger barrel radius.

Steve

 is valid though. hadnt thought of that, just thinking of what folks have laying round they could use.

The whole thing is just a concept Ive been kicking around in my head for a while. Scot gets the blame for the riser, cant remember who suggested the 3 set screws, and i'll take the heat for the rest

 

dr_subsonic's pneumatic research lab

the Lunatic Fringe of American Airgunning
Southwest Montana's headquarters for Airgunning Supremacy
Proud Sponsor of team_subsonic