Building a Cool Crosman 22XX for a Cool 10 Year-Old

This is sort of an extension of a previous blog detailing the addition of an AR-15 adjustable stock to a Crosman 22XX platform.    I've abbreviated much of it so this wouldn't turn into a five part mini-series of madness.  It does jump around a little.  It'll probably be OK. 


Backstory:  Two years ago, with the goal of teaching gun safety and shooting fundamentals, my neighbors purchased a Crosman Custom Shop 2240 with the optional 1399 shoulder stock for their 12 year old. They quickly found out that a 1399 shoulder stock has a rather LONG length of pull.  By LONG, I mean it's too long for 6' tall knuckle-draggers like me.  Completely unsuitable for their 12 yr-old daughter.  The easy solution was to copy my wife's Crosman/AR 15 stock set-up as described in the link above.  We sourced an MFT stock and buffer tube, made another stock adapter and it all worked out perfectly.

Now, it's the brother's turn.  Except he's 10--and this time we know going into this what he needs.  A used UTG Pro AR stock and buffer tube were purchased online for cheap.  His gun is being built from an assortment of Crosman 2240 and 2260 parts rather than starting with a preassembled gun. 

I've seen some of the AR stock adapters for the Crosman 22XX guns.  They're OK, though I find them a bit long and bulky because they utilize the buffer tube thread.  That works, but I'd rather cut the buffer tube threads off and sleeve the buffer over the adapter.

This knocks about an inch off and allows the adapter to be smaller in diameter.   The largest diameter of the adapter fits inside the tube.

So, here's a truncated version of machining an adapter.   It replaces the Crosman tube plug on the gun.



Detour #1:  As I did for my wife's project gun, a Benjamin Marauder pistol forend was fit after modifying a Crosman 2250 barrel band and hardware.

Turned an acetal plug to fill the hole for the pressure gage.





Detour #2:  A forward sling swivel.  Rifles need slings.  Ask anyone.

My current favorite way of adding a sling to a Crosman 22XX platform--a modified 2250 barrel band.  Set screws added to the sides at 4 and 8 o-clock. 

Made this.

Used a permanent loctite on the threads for the sling stud. 

OK, enough detours.   Back to making the rifle fit the kiddo.

 

Here's the (WAY too long for me!) Crosman 1399 stock.  The six-position AR stock is at full extension and fits my 6' frame perfectly.

 

And more importantly, the UTG stock at it's shortest compared again to the 1399.   Of course, I forgot to write down the LOP.  Think it was 8".  It's really short.




Here's what I gave his father.  It's my jaded take on a 10 year-old's first air rifle.   A 2260 gas tube and a cut to length barrel.  Keeps it short and in proportion for a 10 year-old.  Used a Crosman steel breech with a simple red dot sight.  Made sense to give him a similar sight to what he was already comfortable with from using his sister's gun.    It's a .22 caliber.  The bigger pellets are easier for the kids to handle--and its the same caliber as his sibling's.

Before dropping it off, I shot it for the better part of a week and a half.  The carbine length is appealing.  Fast, light, easy to carry slung.  Really liked it.  If he wasn't such a good kid I would've kept it, grinch that I am.

Yeah, you know how this ends.  He was elated with the rifle.  He's allowed to use it with his parent's supervision.  They're happy it actually fits and appreciate that it's not a cheap toy, but is accurate, easy to use and can be adjusted as he gets taller every week.

Anyway, I'm hoping Crosman redesigns the 1399 stock.  I've read several online posts about parents running into this same problem.  It'd be pretty slick if they made a length adjustable stock that would retrofit to all the zillions of 22XX and 13XX guns out there.  Oh, and a longer forend. With a built in sling QD socket.   And while we're talking about it...


More soon.  Thanks for reading along.

AR-15 Stock Adapter for a Crosman 22XX -- Part 2

The Crosman project for my wife continued to evolve over the last few weeks.

















I replaced the short 2250 forend with a longer forend from a Benjamin Marauder pistol.  Cut down a 24" Crosman 2260 barrel to 20" and made a carbon fiber muzzle brake.  The grips were also updated to the newest style from Crosman's P1377 pistol. 






















Mounted a UTG hand stop.  A long #8-32 screw holds the hand stop as well as anchors the front of the forend to the barrel band.

This is an AR-15 accessory designed for the KeyMod rail.  The radii don't match, with a gap between the hand stop and the forend, so no modification to either part was necessary. 

Turned a press fit plug from acetal to fill the unused pressure gauge hole.   It actually doesn't look so bad in person.  Think the diameter ended up at 1.025".

A UTG 11mm to Picatinny adapter carries the theme.  I was pushing for a UTG 4-16X scope, but my wife thought it was getting a bit heavy.  A Crosman labeled 3x9 with AO is lighter and should provide all the magnification a CO2 rifle really needs.

MFT stock fully shortened.




















And extended.

We'll need to get some range time before taking it much further.  I'm still debating whether or not to convert it to .177.  I expect that might give a flatter trajectory and a bit more range for those tin cans.

Thanks for checking in.

Re-Cutting the 22XX Dovetail for a New Sight

Wanted to make some forward progress on a rear sight for one of my 22XX guns.  The odd dovetail angle size on the Crosman steel breech meant either buying a specialty cutter of doing the work by hand.

Elected to re-cut the factory dovetail to 60 degrees.  It was an easy decision to make since I already had a cutter.

Set it on parallels and protected the sides with some heavy paper.

Cut it a couple thousandths deeper than I really wanted to, but once it's blued up and there's a sight installed, it really won't be noticeable.

A couple passes with a triangular file and it's good to go.

Next up, I'll start the body of the sight.

The 22XX Takes a Brief Detour

Was gonna start making a rear sight for the 22XXwhateveryouwannacallit from the last post and I somehow got sidetracked.  Seemed that such a large pistol should produce a bit more oomph. 

Started by cutting about a third of the threads off the front half of the valve.  An untouched half is on top...  This increases CO2 volume inside the valve.

A 1/4" diameter end mill was used next.

Again, this increases volume.  Obviously, the modified valve front is on the left.

Chucked a tiny ball mill in the Dremel.

This is the rear half of the valve.  Relieved the sharp ninety degree corner at the bottom of the transfer port.  The goal is to smooth out and radius the edge.

Cut a counter bore on top of the transfer port.

...and a similar counter bore in the breech end of the barrel.

Replaced the stock valve spring with something much softer.

Probably unnecessary, but the valve body threads got some teflon tape.

Since the valve gained so much additional volume, safety concerns dictate beefing up the valve securement in the gas tube.  Beats having the valve become a potential missile.  The red tape was used to help with layout for two additional valve screws.

I've done almost these very same steps during the AirSource project here.

Set-up was a bit different due to the use of the 2260 gas tube.  A jack screw held up the off end.

Spotted and drilled with a #29 drill bit, followed up with a 1/4" to counter bore for the screw heads.

Tapped the holes #8-32.

Turned down some #8-32 socket head cap screws to 0.248".

The socket heads stick out a wee bit.

Just enough to be too much.

Faced 'em down in the lathe and rounded the heads over with a file.  I'll blue these later.

With the counter bores cut for the transfer port, the stock transfer port tube was too short.  I cut and faced a short piece of 0.250" diameter brass tubing.

The initial idea was to use a small o-ring at each end of the tube to effect a seal.

Like so.

Tube gets sandwiched between the o-rings.  Well, it will once the breech is installed.  (There's one of the blued screws)

And here's the o-ring mate in the breech.  In practice, this didn't work very well.  Ended up changing from o-rings to thin discs cut from 0.250" diameter vinyl tubing.  The tubing was stiffer and didn't collapse as much as the o-rings.  Sorry, no pics of the vinyl.  Maybe later.
















And here's where this whole experiment goes both right--and wrong. The gun hits 600 fps with a .22 cal RWS Hobby pellet--that's 150 fps faster than a stock 2240.  Some of the gain is no doubt simply due to the 13.5" barrel length--about 6" longer than a stock Crosman 2240.  The wrong part is the absurd usage of CO2.  The shot count went down to around 8 or 9 shots.  I forget exactly just how many because I was too busy changing cartridges to actually keep track.  Crosman can barely fill them as fast as this gun can empty them.  I can't live with the low shot count, so I've changed the front half of the valve and valve spring back to stock.  The gun with a slightly stiffer hammer spring is now putting out 550 fps and getting about 25+ decent shots before it drops below a useful (to me) velocity. 

More in a few days.