The way I got to the pump/over pressure release valve was to carefully dremel around the end cap. My appologies for less than perfect image quality, but it might do for getting a general image.
. . . . it shoots pretty well, but only if you pump it 25 or so times... any suggestions would be appreciated. thanks.
p.s. how can i get to the over pressure relese? its glued on pretty solidly.
Notice the litlle posts on the end cap, and how I cut down the center of them? (Ok, in theory, at least. Sorry about the poor focus.) Put the gun together, and it helps keep the now-loose end in place. In the meantime:
You can now plug the release valve to your heart's content. But wait, there's more! I don't know if anyone else has run into this issue with their Big Salvo, but mine was not the most effective at pumping. While pumping, it would often feel like it wasn't building up any pressure. When I looked at the pump, particularly without the o-ring on, I noticed the following:
You might notice a bit of an angle to the area where the o-ring went that keeps it forward. If it is to push air into the chambers, that o-ring apparently needs to slide back. So I filled in some of that narrower space by putting a small rubber band on, in front of the o-ring:
After this, it pumped much more effectively for me.
One more issue I had was the lovely discovery of a leak. Upon investigation, I found that the air was leaking out the trigger mechanism.
On the monstrous trigger, the rod that goes into that blue assembly with the tubes has an o-ring on it. On my Big Salvo, it apparently wasn't making a tight enough seal. So I placed (didn't stick with all that lubricant on it) a couple layers of a thin strip of electrical tape I cut for the purpose. Once I got those to stay in place while I put the o-ring back on, I had a tighter fit, and it seems to be holding pressure better.
Hopefully this might be helpful to people discovering both wonders and frustrations with this gun.