Wednesday, March 24, 2021

Crosman Project Mashup!

Having trouble trying to figure out how to write the intro.  Sometimes the blog posts just kind of flow.  This isn't one of those times.  Over the years(and blog posts), I've made several parts for my various Crosman 22XX airguns.  Recently combined a half-dozen of those projects into one gun.  Here's the pieces parts that made the cut.  I'll try to link back to the original posts for each project.


 This probably started as a Crosman 2240 pistol.




After shooting a Benjamin Marauder PCP, I wanted those same 10-shot magazines to work on one of my 22XX guns.


At the time, the only solution was to make a new breech for my Crosman air pistol that accepts the mags. 

Left side bolt is a straight pull.  Locks in battery and locks open to change mags.

The handle is spring loaded to lock into the recesses at each end of the cocking slot.  Shove it forward to chamber a pellet and let it go.  It locks automatically.  Fire, pull out and back, shove forward to chamber and fire.  Fast and simple--my poor man's version of a biathlon action.

Locked to the rear for a magazine change.

You've seen this before a few times.  A machined gas tube cap under there that accepts AR-15 stock buffer tubes

Which in turn, accepts AR-15 adjustable stocks like this Magpul MOE. 








A keymod QD sling socket attachment was added to the stock.















Because guns need slings. 




Just had to make this special tapered nut and use longer screws.





Magpul .75 cheek riser.

OK, now this is where this particular project starts to make sense.  That Marauder 22XX magazine/Breech project was great--until I installed it on my 22XX.  Since the 22XX guns only use a single 12 gram CO2 cartridge, I got three magazines before the gas ran out.   Three whole mags! Then the fun just dribbles out.    The old Air Source tank block project was the perfect solution to the lack of CO2 capacity. 

Here's the tank block.  This allows the attachment of a CO2 tank instead of just using the typical 12 gram cartridge.  



Now I can use any CO2 tank I have on hand.  


Here are a couple options.

Most of the time, I expect that I'll use an 88/90 gram Air Source type tank.  Although these are supposedly single use, disposable steel tanks, it's possible to fit a check valve to an empty Air Source tank and refill it from a larger 10 or 20 pound CO2 tank. 



I bought this particular check valve at an airgun show.  Side note:  It didn't work.  Was designed using a radial seal on the check (???) instead of the more common flat face seal.  Had to machine a new valve seat and make a teflon seal washer. 

Quick detour:


Made a quick sling attachment loop from a piece of scrap of steel.


Fits over the 16mm threads of the Air Source valve.

 An o-ring takes up the additional gap and leaves the loop wherever you rotate it.

The hole is for HK-type sling hooks.

OK, back to the story:

With a full 88 or 90 grams of CO2 on board,  I'm looking at 20 magazines before the gas runs out.  Two hundred shots of fun.















And I'm not locked into only using my oddball refillable one-off Air Source tank.   Disposable 88/90 gram CO2 tanks work.   The pin in the tank block must be changed out for a sharp piercing pin, but that's a few seconds with a pair of needle nosed pliers. 

Next, I looked at some of my other CO2 tanks and saw some easy cross-compatibility.
















Skinny paintball tanks fit under the barrel.  The old aluminum 3.5 oz Parker tanks (small one on the left) seem like the best option.  These screw right in with a "paintball to Air Source" adapter.  That's the silver thingie in the above pic.



Small and medium (roughly 3.5 to 9 oz) sized paintball tanks also work with a paintball-to-Air Source adapter.  With a longer paintball tank, I should be closing in on 1,000 shots for a single fill.

OK, what else can I come up with?   I have four or five refillable Czech-made steel CO2 tanks for recharging my Aeron target pistols

These are sort of a female-threaded version of a paintball tank.  If, uh, paintball tanks had 18mm ID threads.



 I made this adapter just so I could refill the CZ CO2 tanks when they ran dry.  Actually, I think this is the "MK2" version.  The lack of wrench flats on "version 1.0" was an annoying oversight. 









So now these Czech tanks can run on Air Source guns, too.

And finally, if there's absolutely no other choice:

This is a 12 gram adapter to Air Source, so I've come full circle.   Actually, now I'm going backwards.   Back to 30 shots and the fun is over.

These cheap adapters cost about $15.  There's really no good reason to have one of these unless you're afraid of running out of every other better option.  And no, I don't have two of these.  Yet.

Turns out the cheap piercing pin in the valve of the adapter wasn't hardened and failed after about 10 cartridges.

I removed the dead piercing mechanism and machined the end to take a standard Crosman 38T/357 piercing pin and end seal.  Easy to find repair parts!

OK, I'll wrap it up.

UTG red/green dot is fast to acquire.  I've had surprisingly good luck with the UTG QR scope mounts returning to zero after removal and re-installation.  Need to check if I have an extra UTG short scope floating around--would be nice to have a 4X, 6X or 3-9X scope option that can be swapped back and forth without re-zeroing. 

Shrouded the barrel in 3K weave carbon fiber


And finally under the grips, there's a couple spare o-rings for the tank block and that additional piercing pin needed for disposable Air Source cartridges.  A rare earth magnet glued to the grip frame keeps the pin from going astray or rattling. 

Suppose I could add a spare Crosman valve body o-ring and valve stem as well.  Yep, this is what I've been tinkering with of late.  Still have a bunch of projects in the que.  More soon.


Thread sizes of some of this stuff:

Air Source thread:  M16 x 1.5mm

Standard paintball tank:  1/2" BPS x 14   (Half inch British Pipe STRAIGHT x 14 tpi)   this is NOT a tapered thread

CZ/Aeron /TAU CO2 tank  M18 x 2mm

Stay well.