Disco Double Carbine

[Bobbieone]

Would it not be easier and safer, if you need more air to use a larger diameter tube , this would reduce the bit's needed to connect it all together, or am I missing something  ?,

[rsterne]

Well, if you go larger, you need to increase the wall thickness of the tube by the same proportion.... to get the same volume, you would need a ~50% increase in OD, and the wall would have to be ~50% thicker as well.... The MRod tube is exactly twice the volume, at 1.25" OD x 0.095" wall, and you would then need a larger valve and hammer to fit inside the larger tube.... So basically, you would be building an MRod....  There is no difference in the safety if properly engineered and constructed....

Bob

[David Mccann]

great info here folks... thanks for sharing the safety issue point. i will definitely secure that rear plug with screws. this will be the res setup on my next project. thanks again for sharing the info..gooday

[BC81]

So i have a few pics of the tube. Sorry they're from my phone, i couldnt get a good one of the fitting but it looks fine to me. You can see were the fitting did get pressed against the tube but it isnt distorted badly. Just marked up a little bit. Think its okay, provided i anchor the block with the screws?

[BC81]

Did some measuring and there isnt enough meat for the gauge port and the bottom 10-32 screw. I got the pilot holes drilled so far and can tell it will eat into the screw hole if i try. I might buy another gauge block and put it in front of the lower transfer block and mount the gauge there. If i keep this a carbine, i will probably mount it sideways. If i do go rifle, i will just get a 2260 stock and move the gauge location forward in the stock vs filling the one in mine i have already. My wooden stock is actually a 2260 that i drilled out the hole anyways so i already know it works. The 2260 stock is about $20 cheaper so figured save where i could and spend it on more parts!
Will post pics later when i get the holes done and gun back together.

[BC81]

Ok, got the gun back together and have some numbers.
First two pics are with EunJin 28.4 domes, and the next two are with kodiak 21.14s. They are the high and low over 10 shots with the RVA cranked to just shy of coil bind and .041" spring on a 2800 psi fill. I will tune for shot count later.

[BC81]

These are the Kodiaks

[BC81]

Oh yeah, here is a pic of how i secured the lower gauge/transfer block.

[BC81]

Im probably going to buy an AR2078A target stock and inlet that for the double tube action. There is more material to work with and should be pretty easy since I've already done the TH stock version. Pretty simple with a dremel, drill press and forstner bit.
Guess that means i have to build ANOTHER disco to put in the empty factory stock. Probably make that one a detuned .22 version for more shot count and neighborhood friendly.