How Much Pressure in a converted Beeman ar2078a.

[RayboyUSMC]

I had the Beeman QB 78S a while ago. Sold it and moved on to the Beeman ar2078a which is very similar. It takes the two 12 gram CO cartridges. When I had the 78S, if bought a front cap for that gun that had a PCP fill valve on it. It didn't work on that gun. I tried it today on the ar and it works beautifully. Holds pressure and puts a 10.8 gr .177 pellet almost a half inch into a fence 4 x 4 post.

I used my new electric pump. Boy that beats the hell out of pumping by hand when you are an old fart. Put it up to 1100 PSI.

Does anyone know what the safe upper limit would be? Should I be just be happy with the 1100 and a new PCP rifle.

By the way, this is the most accurate pellet rifle I have ever shot. At 10 meters, my back yard, I can keep the shots all touching.

Any good safety information would be appreciated.

Ray

Semper Fi

 

[dizzums]

no idea .. i dont think co2 stuff is rated even that high .. if its working id be happy and not push it, and maybe wear a football helmet and safety goggles when your filling it lol .. id definitely be careful though ...

 

[RayboyUSMC]

There was an article where someone converted one, but they did a bunch of changes internally. They went to 1500 PSI.

I will keep it at about 1000 for now. Will have to check how many shots I get. But with the new pump, it is no big deal.

Thanks for the info.

 

[biohazardman]

Co2 guns converted to PCP can be very dangerous even deadly if appropriate measures to secure the valve are not undertaken. I saw a you tube video of one that sheared the undersized single screw holding the valve and put the whole valve all the way though a mans thigh. The valve stem was sticking out the other side of his leg. Could have easily killed him if it had hit elsewhere or an artery. So, this kind of conversion should be undertaken very cautiously.

That being said I have looked at the diagram of the gun and it looks to have two screws holding the valve. I don't know what size or if they are hardened or not. With Chinese metallurgy being what it is I would not trust them to hold up past the likely werqing pressure of 800psi the gun would have for Co2. Still with that werqing pressure it should be designed to hold 1200 to 1500psi max. as Co2 can get that high on a very hot day.

Were it me I would keep it down around 1000psi like you are planing on doing and not push it to the point of shearing screws.

With some larger hardened screws in the valve 1500psi would probly be safe.

 

[RayboyUSMC]

Thank you. I will keep it at 1000 for now.



I am looking for a parts diagram for this gun.. I might just go to the QB-78s which is probably the same.

 

[biohazardman]

 

Found this on google says it is for a Beeman ar2078a