BBMG operating pressure?

[spudnutbutthut]

I want to make a 3/4in cap bbmg. I want to run it with propane that expands in a 4inch 3 ft tank. Id be firing at around 60 psi at max, and 90 if i let it sit for a LONG time. Is 50-60 enough to fire bbs with substantial force? I will have a 450 mm barrel.

[spudnutbutthut]

Does no one know? What pressure do you operate YOUR cap bbmg at?

[cannon monkey]

i guess not i would say 60-75 psi?

[Ragnarok]

Is 50-60 enough to fire bbs with substantial force?

You'll need to give a numerical measure for "substantial force", because "substantial force" is very subjective. What I consider to be substantial force is unlikely to be the same as you consider to be substantial force.

And let's not even get started the definition of "substantial force" some of our more... radical members would use. Suffice to say, it probably has a two block safe distance.

[jimmy101]

I suspect that even with an input pressure of 60 PSI the gun will actually be running at less than 20 PSI.

With a 120 PSI compressor most BBMGs have chamber pressures of less than 20 PSI.

[jackssmirkingrevenge]

I suspect that even with an input pressure of 60 PSI the gun will actually be running at less than 20 PSI.

With a 120 PSI compressor most BBMGs have chamber pressures of less than 20 PSI.

One could always follow the man's advice to boost that easily.



... or put the BBs in your chamber and behind the valve like I did here:

[irisher]

I would not recommend using propane. The odor additive will linger and you will be standing in a cloud of flammable gases. Btw I run my vortex cap at ~200 psi.

[spudnutbutthut]

Im thinking id be using .12 or .2 grams, itd have to be around 350fps and fire around 80 ft?

[jackssmirkingrevenge]

Im thinking id be using .12 or .2 grams, itd have to be around 350fps and fire around 80 ft?

It shouldn't be a problem, with 0.12g BBs and 80-90 psi in this ghetto device I was getting this sort of performance:

[youtube][/youtube]

[Marffy]

50-60 will do but i run mine all the way to 150

[Brian the brain]

900 psi.
Okay..not a cap vortex..just modded elbow vortex thingy
later turned into regular cloud design..

But I sold it...

So I'm just bragging..

[jimmy101]

Another reason not to use propane in a bbmg, at least if you are using copper/steel BBs and not airsoft.

BBs will throw sparks when they hit things. Concrete at short range will spark. I wouldn't be surprised if there wasn't' an occasional spark from a steel barrel.

Be very bad if the occasional BB threw a spark after a couple mnutes of firing in calm air.