BNM multishot on a 2240 platform

[Larspawn]

Hi all,

Got a question for you.  I picked up a BNM multishot breech for a Disco.  Rather than mess with my Disco which is in a custom stock I thought I would graft this baby onto a 2240 frame.

The breech I got just came with a bunch of parts.  I was able to get it all back together.  It cocked and dry fired fine.  I loaded up a CO2 cart and it also cocked fine.  However, when I pulled the trigger it just dumped all the gas.

Everything lower is stock 2240.  I only replaced breech and barrel.

What would cause this and any ideas to look at? 

[7624452]

Did you install the extended transfer port ? (top right item in picture)   

[Larspawn]

Yes. It came with two different transfer ports. I used the smaller one. But that's not it as it held air until the first hammer strike.  I'm guessing something like the hammer spring is bound or something.

[Larspawn]

I took it apart and then reassembled.  It now works fine!

Now just have to figure out how long I want to cut the Disco barrel and where to source a shroud that will fit.

It is 23.6mm/.930 inch.  Welcome to any ideas on shroud and barrel length.