Homemade PCP shotgun

Building or modifying BB, Airsoft, and Pellet type of guns. Show off your custom designs, find tips and other discussion. Target practice only!
Fella
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Sun Dec 24, 2023 1:59 pm

Hello! I am new to this forum. I’ve spent the last couple months planning out the building of a PCP air rifle. I wanted to run the specs by this forum before I began building.
The specs:
It will be a lever action shotgun, with 1/8” thick aluminum as the barrel. The air will travel into the barrel via a 1/4”+ thick steel tube. Both will have emergency burst discs. It is lever action, so the barrel swings forward. This will cock the hammer. When I pull the trigger, the hammer strikes the firing pin, which in turn strikes the valve stem (more on that in a second). It works essentially like a real gun, except the firing pin strikes the valve stem, not a cartridge. The valve itself is a Z valve (Huben Power Short Z valve, unless someone can recommend something better). I’ll connect it to a 4500 psi rated tank from amazon (although I don’t expect to ever pump it past 2k psi). I’m buying the valve and the tank premade because I am not confident enough as a machinist to make something that holds that ridiculous amount of pressure. My only concerns with this are:
Will I lose significant power because of the way the barrel swings open?
Are the materials I am using strong enough to handle ~800 psi of regulated air?

I will try to attach blueprints later. I’m quite proud of my trigger mechanism, I set it up so the air tank can be kept in the stock, not facing forwards like on most pcp guns). I would love to make it bolt action, but it seems a bit too difficult for a first project.
Thanks
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jackssmirkingrevenge
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Tue Dec 26, 2023 3:00 pm

Welcome to the forum! It's a little hard to picture your project without images, and can you link to the valve you intend to use? To my knowledge the "Z" type valves are intended for AirForce Talon/Condor type rifles that have a hammer coaxial with the barrel.

If the dimensions you described are wall thicknesses then you should be fine at 800 psi without needing burst disks, although of course not all alloys are created equal.
hectmarr wrote:You have to make many weapons, because this field is long and short life
Fella
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Tue Dec 26, 2023 7:44 pm

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jackssmirkingrevenge
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Wed Dec 27, 2023 2:11 pm

Something like that then:



Good to have the difficult part pre-made :D
Will I lose significant power because of the way the barrel swings open?
You said it would be lever action, technically the barrel would be fixed - did you mean break-action like a traditional side-by-side or over-under shotgun?
hectmarr wrote:You have to make many weapons, because this field is long and short life
Fella
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Thu Dec 28, 2023 4:35 pm

Yes, it is break action. Apologies for the confusion- I’m new to pcp and the terminology. It’s exactly like the one shown in the video. I am nearly done with the CAD.
quinn whitsitt
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Fri Mar 01, 2024 11:03 am

great job and i want everyone to have a great day
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