Marauder Three Custom B-Rods

[rsterne]

I love customizing, modifying, and building my own guns.... Here are three "Bottle Marauders" that I put together a couple of years ago.... They all use M-Rod receivers and magazines (modded for calibre), and shortened tubes to give a generous plenum....



The top one is a .357 cal, the middle one a .30 cal, and the bottom one a .25 cal, all running TJ's barrels.... They use regulated 500 cc, 3000 psi bottles, set to different pressures depending on calibre.... They all run balanced valves of some kind, a Cothran Powerhouse, an ART/SS, and my own design.... and they all run SSG's on the hammers (Stopping Spring Guides) to eliminate hammer bounce.... Here are the performance curves for the three different calibres....







The X-axis on the charts is the SSG Gap between the hammer and valve stem....

Bob

 

[hameditor]

Bob, thanks for sharing! Did you use the same size plenum for all three? It's tough to see from the photograph. What calculations did you make to determine the plenum sizes?

 

[rsterne]

Yes, I used the same plenum for all three.... I actually got them from Travis as surplus from one of the guns Wicker Air Rifles was building.... They are 69cc, which is plenty for the .25 cal, OK for the .30 cal, and probably a bit small for the .357.... but all that really costs me is having to run maybe 200 psi higher regulator setpoint and a bit of efficiency.... The tank block on the .25 cal is from a Cobra, with the regulator built in.... hence no reg. between it and the bottle.... All the tank blocks were surplus W.A.R. parts as well.... Realistically, you can trade off power vs shot count by changing the regulator setpoint, and retuning the SSG gap.... 1900-2200 psi gives a nice balance....

Bob

 

[Pguadalupe]

I love customizing, modifying, and building my own guns.... Here are three "Bottle Marauders" that I put together a couple of years ago.... They all use M-Rod receivers and magazines (modded for calibre), and shortened tubes to give a generous plenum....



The top one is a .357 cal, the middle one a .30 cal, and the bottom one a .25 cal, all running TJ's barrels.... They use regulated 500 cc, 3000 psi bottles, set to different pressures depending on calibre.... They all run balanced valves of some kind, a Cothran Powerhouse, an ART/SS, and my own design.... and they all run SSG's on the hammers (Stopping Spring Guides) to eliminate hammer bounce.... Here are the performance curves for the three different calibres....







The X-axis on the charts is the SSG Gap between the hammer and valve stem....

Bob

Love It!!

 

[Pumacarl]

I just wanted to bump this post back up, now that over two years later, a G3 has been announced for next year. These builds have been happening for quite a while, with very knowledgable people working on all the porting, plenum, and hs details already. With so much legwork already done and proven, it will be really interesting to see what makes the cut into production, and what doesn't. Especially since it is going to be a completely new gun and has no legacy parts concerns.