Mounting a Fuseend 3X28 IR Compact Scope to my .20 Cal Crosman 2050

My simple red dot equipped .20 cal carbine project didn't stick.  Mostly because the red dot wasn't doing it for me.  Or, mostly because I'm weak and wanted a shiny new toy.  I was scrolling ebay for I don't know what, when I found a small 3X illuminated compact scope. 

And just like that, some 30mm dovetail rings from UTG almost finished the project.

 

 "Almost" because that front ring ate up too much real estate on the tube.  I'm not a die hard lens cap guy, but a thinner ring would hold the scope AND allow for the cap.  Of course, no one makes that.   

Off with the ring.

The set up in the milling machine was a bit tenuous.  The 1-2-3 block gets the clearance above the vise jaws.   Couldn't find a great way to hold the ring as securely as I wanted.  Lighter cuts will have to suffice.

Want to remove half of the 30mm clamping band and allow clearance for the scope cap-- but leave the two-bolt dovetail portion untouched.

And I didn't want a sharp corner at the bottom of the cut left by the endmill. 

A gage block stack representing HALF of the original ring thickness.

This went on the 1-2-3 block the ring is supported on.  Changed to a 1/4' ball mill and touched off.

Set the Z-axis to zero. 

Brought the base of the ring to zero with the ball mill.  

This gave me a radius--rather than a sharp 90 degree corner at the transition

Repeated with the flat bottomed milling cutter.  Touched off on the same gage block stack.

And re-zeroed the Z-axis.

Looks OK

Deburred and gave it a quick hit with some sand paper and a scotchbrite pad.

Ready to retouch the color on the milled surface.

And it's ready to install.

Cap-Less

 

Cap-Ped.  Good clearance and fit.

And I don't think it looks like I messed with it.  So, that's a win, right?

I have some brief thoughts about the scope I'd like to share next time around.  It won't be a product review.  

Modified CO2 cap with a QD Sling Swivel on a .20 Cal Crosman 2050 Carbine

I'm always changing configurations with my various Crosman 22XX guns.  Their modular design makes it easy to go from pistol to carbine to rifle and back in a few minutes.  Combined with a few adapters, I've been able to try several interesting combinations.  In the last blog post, I had thrown together a .20 caliber carbine and wanted to use a vertical fore grip from Magpul.   Assembled, it felt pretty good, but there wasn't a spot for a front sling position.  Granted, a single point rear sling worked just fine, but most of these projects come about from trying to solve a unique problem.

A bit of head scratching and I thought a QD front sling socket could be incorporated into to a modified gas tube cap as an inconspicuous attachment point.

Rather than butcher the original cap, 

Started from zero with a piece of 7/8" diameter 12L14.  

Turned the end down to about .8085"

And threaded with a very uncommon 13/16 - 28 die to match the Crosman 22XX gas tube.

The camera angle is bad, but I used a thin parting blade to cut a relief at the end of the thread.

Since I'm using the Crosman mid-length 2250 gas tube, the cap will need an extension to bear against the end of the 12G CO2 cartridge.  Might as well plan ahead for the three different Crosman gas tube lengths--2240, 2250, 2260.

A #3 drill is the correct diameter--

for a 1/4-28 tap.   

More on this later.  

Cut off the excess.

Cleaned up the face.

Drilled 3/8".  This is where several small errors compounded and went slightly sideways.  The tailstock was a bit out of alignment, the drill bit cut a bit oversize, I wasn't paying enough attention and this probably became a version 1 prototype.  

Bored the undercut for the QD swivel.

Some cosmetic clean up.

A piece of sacrificial 1/4-28 in one end and a UTG 1-1/4" QD swivel kinda fits the other.   A bit loose due to the oversized hole.   Tried six or seven QD swivels and had mixed results.   Half pulled right out, and half worked -- with a bit more wobble than I'd hoped, but they do hold securely.  It's not exactly a disaster, but it will limit swapping and might require dedicating a sling.  

Chucking that sacrificial 1/4-28 stud gave enough room to get a knurling tool in there.

Looks pretty good.

OK, back to making the rod.

Piece of 5/16" diameter was turned down and threaded 1/4-28.

A 1/2" carbide bur produced a concaved end.

Some clean up and polishing.

A bit longer than the Crosman cap.

Blackened with G96 paste and finished. 

Updated 9/25/25:

The sloppy fit got to me.  Dedicating a sling got to me.  And I was annoyed at having my QD sling options limited by that machining mistake.   I want quick and easy compatibility.  I opened up the hole in the cap about .125”, then made a thin-walled sleeve and pressed it into place.  With 0.004” of press fit, it’s never coming out.  And after taking a facing cut on the lathe and some blueing touch up, the repair is invisible.   

More possibilities.  The d-ring on the left allows me to use slings that have a clip on the front end.   I find it much easier to clip the sling to the d-ring than fit a QD push button into place.   

A few more pics:

Short set up with a Magpul RVG and sling.

And with the Strike Industries pistol brace.

Gonna roll with this for now. 

I've always used a Magpul QD as the "standard" and done the machining to make that the best fit.  I do wish that the airgun manufacturers would put a bit more thought into how to make their products better interface with some of the other gun "standards' out there.   I think that means making the airguns accept off the shelf AR buffer tubes and stocks, bipods, Picatinny rails rather than dovetails...  Those accessory purchases go further when they fit several platforms and it makes the end user's ability to tailor the gun that much easier.   Or something like that.  

Thanks for checking in on me.