Vulcan Chain

Many of you have a vulcan and have realised that it isnt awfully that good. Is it possible to use the chains as a 'speedloader' without a coupler.

Slap it on my PETG barrel or will there be an air seal problem?

It could work. Depends how your gun is setup.
If its a single front loader, you could get it to work by simply adding a piece to the end for the dart shell to slip into.
That would look bizzare though, (a chain hanging of the end of a barrel?) and would be arkward to use.
If its breech, it could work, but you would have to modify the breech so the pressure cylinder slides over the dart shells, like it does on the vulcan,.
I cant see any other way for it to work.

I seem to remember ice doing something like that with a pistol splat.

I've seen this done before, but I don't know the particulars. You may just have to find something that the vulcan chain will fit into nicely.