Drev, I
think that your way would deplete the big blast tank any time he fired the Big Salvo. On the other hand, it may just allow him to fire the Big Salvo a second time without having to re-pump.
I believe that this setup will let him fire either the Big Salvo or the Big Blast first:

Note: the objects labeled "CV1" and "CV2" are both check valves. The green are tees. Keep the red tubing as short as possible for the best performance.
You can use the above setup if you promise to stop calling it "SVT style" and just say "I'm going to put a forward facing pump on a big blast."
As to breaking the big salvo:
If both tanks are hooked up via a tee to the same pump, each time you pump will build the same amount of pressure in both tanks. The question is: are you strong enough to keep pumping to the point where one or both tanks bursts? Salvo tanks are known to be relatively fragile, but you also don't need to build a ton of pressure in a big blast in order to get good performance.
My suggestion is to hook the air system components together, and slowly test it: Try something like 5 pumps then test ranges from each tank, then try 6 pumps and range test, etc. If you get to a point where a tank explodes, then get a new tank and pump less times. In other words:
1. Pump up. Count how many pumps.
2. Keep going until you hear a loud "bang".
3. Subtract one pump from the total. Rebuild your air [tank].
Edit: You could potentially close off the Big Blast's stock pump while keeping it's stock check valve intact. That would take the place of CV2.
Edited by jwasko, 21 August 2015 - 02:04 PM.