small propane meter?

[subterranean]

currently i am interested in building a propane meter for a small combustion i built awhile ago. The cannon's chamber is made of 1 1/2" sch 40 pvc, with a volume of 21.6562501 cubic inches. The barrel is 1/2" sch 40. The C:B is 1.5:1. I would be willing to extend the barrel to achieve a .8:1(or similar) ratio. My question is, will i be able to construct a propane meter small enough for the cannon? Im guessing the meter pipe will have to be 1/8" brass,but i want to use 3/8" metal pipe instead.
Any suggestions are appreciated

[noname]

You can make a small propane meter if you want. If it's too big, just use a lower pressure in the meter.

[subterranean]

so if i were to build a meter with no volume specification, theoretically, i could just mess with the pressure until i get it right? Also, do i regulate pressure by just closing off the first ballvalve once the pressure is were i want it , or will i need a regulator. sry but im very new at propane metering

[noname]

I use the gate valve from the propane torch as a regulator. I open verrrrry slowly, and let the pressure creep up about 1 psi per second. When it's at the right pressure, I twist it closed, the open the ball valve leading to the gun.
Yes, you can mess with the pressure, but it's really annoying because you have to vent the propane out of the gun every time.