The as2250 King Ratcatcher is back

[Tack Driver 10]

Awhile back I made an adapter to affix an alternative power source to the back of a tube.
https://www.gatewaytoairguns.org/GTA/index.php?topic=151308.msg1556695#msg1556695

The time has come to finish this gun.
This will be similar to the Ratcatcher but will retain the pumper function.

The plan is to have the ability to run the gun on numerous sources.
Regulated/unregulated HPA, 12 gram CO2, 88 gram CO2, bottled CO2, and lastly, pump the gun like a 13xx.

I'll be using the recently modded Chubbie 2 as the base gun.
https://www.gatewaytoairguns.org/GTA/index.php?topic=177024.0

Here's a picture of a stock Ratcatcher using an 88 gram CO2 cartridge:

[2K1TJ]

Can't wait to see how this one turns out!

[Gertrude]

Me too

Subscribed.

[Tack Driver 10]

Did some digging around to get some info on the gun.
There are several versions but the one I'll be replicating is the gun with the CO2 adapter on the back end of the tube.

There's an external side connector that links the valve to the adapter and power source.
Otherwise the gun is very similar to a 2240.
Looks fairly well built using captive o-rings but seems to be prone to leaks.
The gun went out of production about 10 years ago in the states, cost was about $150 retail.

This version will improve the connection to the valve and adapter using solidly mounted dual o-ringed studs.
Caps will fit on the studs linked with a tube.
It'll get a custom wood stock once the details are finalized.

A few pics of the CO2 connection.

[YuccaPatrol]

Do I understand this right? That you'll be able to use the gas cylinder but also still about to pump manually?

Can you refill the gas cylinder by pumping manually as well?

[Tack Driver 10]

Do I understand this right? That you'll be able to use the gas cylinder but also still about to pump manually?

Can you refill the gas cylinder by pumping manually as well?

Right, the line from the cylinder will connect to the valve between the check and exhaust poppet.
So technically the ability to refill the cylinder is possible.
The FX Independence functioned in a similar manner.

Might be risky pumping into a regulated bottle but an unregulated tank should work.
Another option is to remove the gas components, plug the valve hole and use the gun as a conventional pumper.
Lots of experimenting needs to be done.

Here's how the lines will attach to the gun mocked up on a 5/8" acrylic tube.
The stud screws into the valve and the brass cap slides over the top secured with a screw.
The two brass caps will connect with a tube.

[Arkmaker]

Fantastic! I would love to be able to run a 88 gram tank. Don't want to pump but sure did like the AS 2250 version. Great job, I'm sure you're going to get some requests... 👍👍

[Tack Driver 10]

Finished the back end this afternoon.
Since the line will be at a slight angle made it so the cap swivels.
That'll give me a little wiggle room making it a little forgiving.

Should be able to take the gun apart in the morning and machine the valve and tube.

[Tack Driver 10]

Modded the valve/gun to take the exterior line.
Used 3/16" nickel copper brake line threaded 10-48 on the ends and soldered for the link.

Since the port in the tank adapter has yet to be drilled I was able to assemble and pressure test the gun.
Pumped it up 14 strokes to 1000 psi and let it set, so far so good.

Needs more refinement but fine for a prototype and proof of concept version.
The style reminds me of Steampunk machines.
Seems to be all the rage with the trendy hipsters these days.
Hey man, can you dig it?

[Gertrude]

Nice Work !

[Tack Driver 10]

Pumped the gun up to 2000 psi and it held rock solid overnight.
Time to gussy this gun up.

Made a new link from brass rod, center drilled 1/8".
Threaded on one end with a captive seal inside the cap on the other end so it slides in.
Both caps swivel so really easy to install.

Pumped the gun to 1000 psi and if it holds, I'll pump it to 2000 psi.
Should get a chance to test next week when CO2 adapters arrive.

[Tack Driver 10]

Pumped the gun to 2000 psi and it held rock solid for 24 hours.
Drilled the adapter to allow flow to the gun and attached a 12 gram CO2 cart.
Pressure showed around 800 psi at 75 degrees.
Gun has a 2400 hammer spring.

Took 5 shots straight from the cart load, 7.9 CPHPs @ 75 degrees with 24" barrel.
#1= 622 FPS, 06.79 FPE
#2= 613 FPS, 06.59 FPE
#3= 596 FPS  06.23 FPE
#4= 605 FPS  06.42 FPE
#5= 608 FPS  06.48 FPE

With the CO2 cart installed pumped the gun to 1000 psi with a few pumps between shots:
#1= 715 FPS, 08.97 FPE
#2= 729 FPS, 09.32 FPE
#3= 719 FPS  09.07 FPE
#4= 701 FPS  08.62 FPE
#5= 721 FPS  09.12 FPE

A regulated bottle at around 1100 psi would be a good fit.
I don't have any HPA equipment but might "gear up" soon.
Thinking a 13 cu in regulated bottle and a Hill pump.

[Tack Driver 10]

Installed a fresh 12 g CO2 cart, took a few blow off shots and pumped the gun to 1500 psi.
Pressure progressively dropped about 100 psi per shot as follows with no added pumps between shots.
#1= 814 FPS, 11.62 FPE
#2= 788 FPS, 10.89 FPE
#3= 789 FPS  10.92 FPE
#4= 776 FPS  10.29 FPE
  1200 psi
#5= 769 FPS, 10.37 FPE
#6= 743 FPS, 09.68 FPE
   1000 psi
#7= 730 FPS  09.35 FPE
#8= 706 FPS  08.74 FPE

Another option is to attach an empty 88 gram bottle and pump it with a hand pump through a fill port on the adapter.
It would be unregulated but the larger volume should allow a good number of medium power shots.
Would also be very easy to pump with an external hand pump.
   

[2K1TJ]

Turned out sweet!! Very versatile little package.
If you decide to add a bottle, Tippmann makes a 9ci one that would be more pump friendly. Only $49 for bottle and reg.

[Tack Driver 10]

Turned out sweet!! Very versatile little package.
If you decide to add a bottle, Tippmann makes a 9ci one that would be more pump friendly. Only $49 for bottle and reg.

That 9ci bottle looks like it would be perfect for this gun.
Thanks for the tipp  mann....LOL

Installed a 22 cal 20" barrel for more testing.
Fresh CO2 cart pumped up to 1500 psi with 14.3 CPHP, 72 degrees, 1 minute interval.

#01= 543 FPS, 09.36 FPE
#02= 682 FPS, 14.77 FPE
    1250 psi
#03= 677 FPS  14.55 FPE
    1100 psi
#04= 672 FPS  14.34 FPE
  1200 psi
#05= error
    1000 psi
#06= 671 FPS, 14.29 FPE   
#07= 656 FPS  13.66 FPE
#08= 673 FPS  14.38 FPE
#09= 664 FPS, 14.00 FPE   
#10= 670 FPS  14.24 FPE
#11= 665 FPS  13.91 FPE
     900 psi
#12= 662 FPS, 14.29 FPE   
#13= 658 FPS  13.75 FPE
#14= 652 FPS  13.50 FPE
#15= 649 FPS, 13.37 FPE   
end of test 900 psi

The first shot was low maybe because I shot the gun right after I pumped it to 1500 psi?
Had plenty more shots left in the cart but ended the test.
Otherwise fairly consistent, sweet spot looks to be around 1000 psi/14 FPE.
Pretty good considering it has very small valve volume.

I have a 3D printed multi-shot breech slated for this gun.

[Tack Driver 10]

Made this prototype mini Ratcatcher adapter this morning, less really is more....LOL
It shaves 1/2" off the previous version and about 1" off the original Ratcather.
It also adapts straight up to an ASA so no conversion from 88 gram needed.
Should be able to attach a 13 ci regulated bottle without excess length.
Might have to build another Ratty to test it out.

[Gertrude]

Made this prototype mini Ratcatcher adapter this morning, less really is more....LOL
It shaves 1/2" off the previous version and about 1" off the original Ratcather.
It also adapts straight up to an ASA so no conversion from 88 gram needed.
Should be able to attach a 13 ci regulated bottle without excess length.
Might have to build another Ratty to test it out.

Now We're  talking '
That looks NICE.
EXCELLENT  Work.

I've  built a couple of rear bottled PCP  22XX carbines, and my main complaint was not being able the angle the bottle downwards like the ratcatcher.

I would love to be able to do that and achieve a much more comfortable hold and cheek weld.

[Tack Driver 10]

Here it is mocked up on a 2260 tube.
Used a 9 ci bottle with an on/off adapter.
Can use a 13 ci bottle connected straight off the adapter but the on/off would make it too long.
A custom wood stock and a 15" LOP would be perfect.

[Spooner]

Its amazing how you came up with this idea, made the parts, then made it all work. Very nicely done... looking forward to seeing the final product. 

[Tack Driver 10]

Did some more test fitting and a 10 degree drop angle looks to be ideal.
Traced the gun with a skeleton stock and cheek riser which works great with medium scope rings.
The 10 degree angle intersects mid riser with a little left for a bottle insulator.
Have a Ninja 13 ci bottle in the mail that should arrive Saturday along with a slip on buttplate.
Eventually it'll get a custom wood stock.
With a little luck it might fit without excessive LOP.