Custom barrels

Ordered two eleven inch air tube extensions from Mac1 today, but he is out of the bulk fill caps. Why couldn't I just install a foster valve in my existing cap? It's already drilled and the fosters have a threaded end so it should be pretty straightforward if I knew which size valve to order. Tim is pretty adamant that you should only use CO2 in bulk fill conversions. He says you can't compress enough air to give consistency in non-regulated guns. I think the regulated guns are rocking 250 BAR or 3600 PSI. A 12 gram CO2 cartridge, on the other hand, puts out about 1000 psi, but it does it over and over as the liquid gasifies so you get the benefit of high volume from a small source. You mentioned your tube is about 50cc and you fill to 1400 psi. Guess I could pick up a scuba tank and have it filled at a paint gun fill station instead of using a compressor. Your route would be a lot cheaper and less hassle. Now that I've thought it through, it might have made more sense to design a carbon fiber tank into the forearm instead of going the extension tube route. Been here before on similar projects like motorcycle engine swaps and trying to convert HVAC to split minis after a hurricane took out my ductwork. It's always easier in the concept phase!
Sure carbon fiber tank regulated to 800psi would work.
 
Oooooh, that's a lot in one bite! First thing, this is just a hobby, something we do for fun. Infinite efficiency is not neccessarily something we seek all the time. I use HPA/PCP in my C-600 because I like to, even if I get 20 shots compared to 30 or so I'd get with a CO2 cart, it cost me nothing for the air.

I have a room full of PCP's, none of them regulated, no need, they are hunting guns. All I want from them is a couple good shots per fill. My 457 would down a deer, no sweat. In fact, so would my .357, .308 and .257 with well placed shots. I wish you lived close by, I have a 20 pound CO2 tank that is pretty much full that I'd give you. I gave up the bulk CO2 thing after I found HPA/PCP. Still keep a couple hundred CO2 carts around for all the old pistols I collect but those get used quite sparingly. By the way, Wal Mart sells the Crosman CO2 carts by the box of 40 for like $15, a good deal.

Have a look at the Beeman 2027, It has a 50 CC airtube that holds 3K psi, will make over 900fps with a light pellet and dialled down to 6 or 700 fps, will get a bunch of good shots. Set for a nice bell curve, one where the shots in the middle of a string will actually be higher velocity than the shots at the beginning, it will put them all thru the same hole, if you do your part...it has no regulator. Dynamite little pistol and deadly accurate.

Regulators are neat, but not specifically neccessary for good accuracy. That said, I do run a tank regulator when I go to the range. I set it for 3K psi running on a 4500psi firemans tank (SCBA) and even that big .457 will shoot all afternoon from it and drop them thru the same hole at 50 yards. This is a great way to zero in a gun. But as a hunting gun, it'll give me several hard shots from it's own reservoir, which is all I need. If I need more, time to go home.

This is an option you may consider, tethering. Stick a fitting on the front of that gun and run a hose down to a tank that you have ONLY filled to the pressure you want...say 1000 to 1400 psi. Wanna spend a little more, add the regulator in between for like $150 and jack the tank pressure up to 4500 psi...you'll run out of pellets before you run out of air.

Oh yeah, you may be able to use your existing fitting. You'll need a 1/8" NPT tap. This is a tapered thread. Be sure to buy a Foster fitting with a one way valve in it.

Chris
 
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Blackbirds are migrating through for the spring and are cleaning out my wife's birdfeeders, so I pulled out the carbine to take care of business. Afterwards, I started re-calibrating and now it fires readily-available and economical Crosman Premiers better than either RWS or JSB wadcutters. Will be watching for sales at my local box stores. If anyone has a lead on gas tube extensions for a Crosman 600 please reach out. The usual sources seem to have dried up.
 
Have been offline for a while tinkering with other projects, but did want to give a quick report on something I learned from happenstance. Pulled out my Crosman while visiting my son and he showed me up with some darned fine shooting. After I left he ordered me a tin of pellets from Amazon just for the heck of it. Turns out they were Gamo Match Classic wad cutters. I threw a hand full in the gun and to my surprise it cycled better than it ever has, smooth and consistent. Plus, they are cheaper than the RWS Hobby or JSB Diablos. Sometimes the fickle finger of fate works in one's favor.