Author Topic: How can I determine the amount of air pressure in my rifle  (Read 388 times)


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How can I determine the amount of air pressure in my rifle
« on: July 27, 2018, 06:05:53 AM »
Guys please help. 

I have a Brocock Contour Elite S6 that shoots very well. Yet it has no built in pressure gauge so how can I tell how much air (pressure) is in the tank?

Is there an after market gauge that I can hook up to the rifle's male foster fitting that will indicate the amount of pressure still in the gun?

Also, I have the Benjamin Marauder with the built in pressure gauge. I can never get the Marauder PSI to remain at 3,000 PSI as soon as I disconnect it from my carbon tank it drops to 2,000.


I had a guy who tunes PCP's (that for now will remain nameless) that cobbled together an assembly consisting of a male foster fitting connected to a pressure gauge and a sealed off foster fitting on the other side. Of course no way to connect that device to the rifle so I purchased a female foster fitting so this assembly can attach to the rifle. But the gauge doesn't move a bit.

  • Snohomish, Washington


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Re: How can I determine the amount of air pressure in my rifle
« Reply #1 on: July 27, 2018, 08:49:04 AM »
There is no cute and easy way to add a pressure gauge to the Brocock. However, when you fill it, you watch the tank (or compressor) gauge, and turn things off once 3,000 PSI is reached. If you want to know how many shots it will make before it needs to be recharged, the easiest way is to shoot a series of shots through a crony, and watch for the steep drop in pressure.

As for the Marauder, I would expect a leak in the Foster input fitting, or the valve seats. If it leaked to zero pressure, I'd expect an o-ring. The former can be replaced or a new o-ring installed. If it is the valve, then it needs to be R&R, once the gun is "degassed". But, if you go that far, I'd replace all of the o-rings. Or...

You send it to a good airgun tuner, and pay the tariff.
  • Roswell, New Mexico

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.


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Re: How can I determine the amount of air pressure in my rifle
« Reply #2 on: July 27, 2018, 09:42:49 AM »
Hi Paul -
let me ask a couple of questions. If they seem really dumb, it's just because I don't know how long you have messed with PCPs.  And I might be a little dumb...   :o

Regarding the Marauder - have you confirmed before you disconnect the fill hose that the tank gauge and the rifle's gauge are reading the same thing, or at least close?  The air gauges on the marauders sometimes go bad.

Secondly, when you open the check valve to release the pressure in the hose before you disconnect, do you open it very quickly or does it seem to drain for a few seconds?  If the lattter, go ahead and open that pressure release valve very quickly, the check valve in the rifle's fill port should slam shut.   

It sounds like the gauge assembly you described is so you can connect the carbon tank's air hose to it and use it to check the remaining pressure in the tank.  But if you hook that to the rifle's fill assembly, the check valve in the rifle's fill port will keep air from escaping, so the gauge won't have anything to read.  It seems like the gauge would be more convenient if it was made with another hose on the output side to connect to the rifle. Then it could be used as an inline gauge between tank and rifle, and show the fill pressure as you fill the gun.  That is what most guys have on their carbon tanks.
  • Carrollton IL


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Re: How can I determine the amount of air pressure in my rifle
« Reply #3 on: July 27, 2018, 02:07:19 PM »
I have a PCP without a gauge, I don't need to know how much pressure is in it as I know 14 shots and it needs a refill. I keep 14 pellets on the gun after each fill up to keep track of when to fill.

The Mrod- if you are quicly releasing the air after a fill it is probably the male foster, it is a common problem to get corrosion around the O-ring of said foster causing a leak. Degas the gun, remove foster, push out pin in foster, remove the O-ring, take some steel wool to the pin to clean it up, put O-ring back on pin, lube wit sone silicon, replace into foster, screw it back together and give it a try.
Buncha BB guns that I don't get to shoot as much as I like. Grinding out a living on the farm.