HPA airsoft BBMG w/detent seal

[jackssmirkingrevenge]

As soon as I can define what I want to achieve, I will ;P

[lozz08]

Hey Jack, excuse my ignorance but, what does the bolt actually do? Like the rubber seals it, but the bolt?

[Gun Freak]

I think the bolt makes it adjustable.

[jackssmirkingrevenge]

The original idea for this was as a single shot launcher where the chamber would be pressurised with the BB held in the seal by the bolt, and you'd unscrew the bolt to fire. In this context being used as a BBMG, the bolt doesn't really do anything, it's the seal that provides the "detent" element.

[lozz08]

currently I'm working on a design very similar to this but with a tee magazine and silicon glue as a seal. I need to incorporate a hopup somehow...

[jackssmirkingrevenge]

This incorporated with the seal will give you adjustable release pressure and if placed at the top of the barrel, hopup

[lozz08]

having you around has probably saved me a couple of years of fiddling around. It's good because we should advances as a spud civilisation and not repeat the mistakes of the previous spud generation

[lozz08]

what about a screw that pushed directly onto the top of the rubber tube? that would cause the seal to push harder on the top of the bb, and give it backspin, while eliminating potential worries with sealing the bolt because everything is still isolated from the barrel.

[jackssmirkingrevenge]

having you around has probably saved me a couple of years of fiddling around. It's good because we should advances as a spud civilisation and not repeat the mistakes of the previous spud generation

Faith No More said it best, someone's got to do it

what about a screw that pushed directly onto the top of the rubber tube? that would cause the seal to push harder on the top of the bb, and give it backspin, while eliminating potential worries with sealing the bolt because everything is still isolated from the barrel.

What would concern me is the seal getting unevenly squashed, but technically it should work and I believe was also suggested elsewhere, as well as Jimmy's idea to use air pressure outside a flexible seal as a "detent", it's in the adjustable ROF thread. You'd need to ensure the seal can accessed for maintenance though.

[POLAND_SPUD]

adjustable ROF

It an be achieved with a rubber washer/o-ring sandwiched between two fittings

[jackssmirkingrevenge]

It an be achieved with a rubber washer/o-ring sandwiched between two fittings

As you had done here, but he wants hop-up as well.

[irisher]

I did the the screw method on my HPA bbmg. It worked well and it was easily adjustable.

[POLAND_SPUD]

but he wants hop-up as well

yeah but I think it wouldn't be that difficult to build a hop-up using the same method... the added advantage is taht you can adjust rof and hop-up independently...

lol I narrowly avoided another posting fail

I've used such home-made compression fittings in quite a lot of applications and it works surprisingly well... it's both on the fridge compressor and it holds the barrel in place on the semiauto MKIII

This is a very useful method of joining metal parts/tubes & fittings that can be undone quickly with a pipe wrench but holds well (both in terms of pressure and mechanically)

[lozz08]

my problem is I'm using a 1/4 inch tee already where the bottom of the tee is an o-ring seal for a removable spring fed mag (I'm going for a realistic kind of gun here) The barrel screws in to one side of the tee, the other side is the air inlet. I need to incorporate the seal into the screw-in barrel.

[POLAND_SPUD]

I sandwiched the rubber washer between two 1/2" male-to-female adapter (or whatever you call this part)

So it's not that you need another T