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CO2 Bolt action pellet gun

Posted: Tue Feb 03, 2009 7:01 pm
by sputnick
Hey everyone,

I was just watching tv and sketching today, and I actually got into drawing something I thought had some potential,

this is a hammer valve CO2 bolt action pellet gun, the bolt is retracted via the handle on top of the bolt (fig. #2+3), which resets the bolt (fig. #3) then when the trigger is pulled, the bolt slams the valve, giving a burst of co2, the bolt going forward aligns the holes in the bolt and barrel, giving a burst of co2 to the pellet.

Image

FIG. #1= Just my first drawing, just a little snowballing, and getting inspired, this is the only one depicting the trigger mechanism, and with the c02 in a vertical position, it is HORRIBLY out of proportion, but hey, it got me started

Image

FIG. #2= the upgrade of the mech. in FIG. #1, with the co2 horizontal now, and showing the internals, they consist of mainly couplers and nipples (galvanized to contain the unregged co2) and then a reducer to the bolt housing.

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FIG. #3= details the bolt mechanism, since that was not not considered in the second diagram, to compensate for that, the barrel would be elevated slightly more than depicted in FIG. #2.


This is just an idea, and I wanted to get some insight. First, would galvanized steel fittings contain unregged co2? and what about the mech, do you think it would work?

Any thoughts, ideas and harsh criticism welcome!

EDIT new pic to better understand FIG. #2



Image

Posted: Tue Feb 03, 2009 11:46 pm
by mega_swordman
I don't see anything that really jumps out at me as a problem. The suggestion that I have though would be to flip around the hammer valve so that the piston travels backwards instead of forwards. In my mind, this would make building the trigger a bit easier (you only would need one component as opposed to two).

Posted: Wed Feb 04, 2009 1:15 am
by Gippeto
No harsh criticism. :)

The mechanism will work. It has a bit too much dead space, but that's hard to eliminate when working with improvised materials.

The bolt could be improved upon. See attached pic.

I've tested 1/2" galvanized steel fittings here;

http://www.spudfiles.com/forums/the-fai ... 15393.html

Posted: Wed Feb 04, 2009 5:39 am
by Dave_424
Sorry to hijack your thread but aybody have any views on the over and under design showed with the 2240 compared with the coaxail design such as a airforce talon/condor?

Which one would be easier to build an have most potentional power??

Dave

Posted: Wed Feb 04, 2009 7:36 am
by littlebro05
While we are on this topic... is it possible to actually get inner threaded tubes as shown on the crosman 2240 diagram at your local hardware store... it's something I want to take a stab at after I leave high school this year.

Posted: Wed Feb 04, 2009 2:44 pm
by Gippeto
Dave, to put it simply, the talon/condor valve has fewer "bends" for the air to navigate. I believe this would result in lower friction losses, and a higher potential velocity for the gas flow. (More power.)

That being said, the largest percentage use a similar layout to the 2240.

Perhaps force of habit? Consumer expectation?


littlebro, I have my doubts that your local hardware store will have tubing which is threaded internally. Of course it should go without saying,...give them a call and ask. :)

For the record, my hardware stores carry no such item.

Posted: Wed Feb 04, 2009 3:41 pm
by littlebro05
That probably means that I probably have to use a threaded nut with steel threaded tube to actually make the Crosman style hammer valve. Aww man. I think I might make a prototype using a soda bottle then moving on to co2 charger. In Australia I can only buy 8g soda chargers for 6bucks for 10. I can purchase 12g but it's ridiculously expensive... $7 a piece.

Well Yeah I think I went off topic.

Posted: Wed Feb 04, 2009 5:08 pm
by jackssmirkingrevenge
Gippeto wrote:Dave, to put it simply, the talon/condor valve has fewer "bends" for the air to navigate. I believe this would result in lower friction losses, and a higher potential velocity for the gas flow. (More power.)
True, indeed the Condor is one of the most powerful production air rifles without using up excessive amounts of air.

As to the subject of this thread, I'm not sure - it will be a lot of time and effort for something which ultimately probably won't be much better than a sub $100 chinese rifle.