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.


Leon Yrag said...

your (infrequent) posts are most appreciated.
kelowna bc canada

Paul said...

Fascinating project indeed. Crosman really hit it out of the park on their 22XX based guns. The possibilities are astounding. Plus, I'm astounded at the options you have on hand!

Anonymous said...


What an awesome little carbine! That action is to die for! I really like how it operates. I would like to have one of those in a right hander for my Maximus.

P.S. I have an old model 3-9x32 that you might like for this carbine.

I do not have the shade or lens caps and you might need to get a mount similar to this.


derrick38 said...

I found a couple old bug busters in the parts bin yesterday. A fixed 4X and a 6x. Tried one, but didn't find it to be as convenient as the dot. I do appreciate you checking! I'm right-handed also, but think this side-locking mechanism might get tight for finger space if it was on the same side as the Marauder magazine. Of course, it was initially for a pistol, so not disturbing the grip hand was a good thing. This carbine is light enough that I can cycle the action with my left hand while it's still shouldered and pointed down range.

Anonymous said...

I really like the simplicity of this action, especially the operation. Even as a single shot it might be a nice little item. The Maximus with a stock striker spring is a hard cocker. The lever is a big help with it's mechanical advantage. This may not be easier than the bolt on a Maximus but I suspect this is much stronger and less prone to sidewise pressure.


derrick38 said...

As a single shot, you’d probably need to lock the handle in the rearward position to load. There’s no need to do that using the Marauder magazine. Just have to pull back far enough to let the mag index to the next pellet. It was an interesting idea and I’m surprised it works as well as it does.

Anonymous said...

This particular blog of yours almost had me convinced to give CO2 a try again. Maybe I will do something similar to my Maximus. We shall see. I do like that action of yours.

As for the single cartridge adapter, perhaps you could make an adapter that you could put two cartridges in butt to butt with a piercing pin in each end to do so when tightened and sealed down all the way, flooding the cylinder and feeding the carbine?


derrick38 said...

Almost convinced? All the platforms--spring piston, PCP, multi-pump...have their advantages. As long as those advantages line up with your needs. I would imagine that if CO2 airguns were only just developed last month, we would all marvel at getting 30 shots from that convenient little 12g cartridge. Imagine being able to put a couple in your pocket and shoot all afternoon!

As for the dual cartridge adapter, I'd be inclined to buy the one from Umarex if I needed a fifteenth way to gas up this Crosman.

Ryan said...

I hope the Crosman marketing folks are doing their jobs and catch your mods in their market research. I would love to have a 22XX platform that accepts Marauder Mags and has an AR style stock. I would buy several extra mags and shoot more Crosman 14.3gr pellets and use more Powerlets which would be a profit center for them. It is shocking that AR end cap adapters are not common place as an after market item. Yours is more svelte and provides an even shorter length of pull. My seven year old daughter is not quite big enough to shoulder the Crosman M4-177 when the faux AR stock is fully collapsed. I think next summer will be the ticket.