Keeping it short, but powerful

[2K1TJ]

I just bought a 2240 and want to convert to hpa. I know shot count will be super low, but hear me out. My goal is to make it as powerful as possible (12-13 +/- fpe?) for I'm guessing 3-5 shots. I may be a bit optimistic on both, but I guess I'll see. I know it'll be loud and waste some air, but I accept that for this build.

I'm wanting this both as a backup for hunting for a close up finishing shot after bad shot, and to carry on my side in the yard while doing yard work incase a squirrel, chipmunk, or venomous snake presents itself. I live in the city limits, so I can't use PB here. Range will be 10 yds or less. More like 5.

Here's the plan, which may change based on advise here.
-Factory 2240 barrel (7.5" or whatever it is). May go to 10" if I don't like the numbers I get.
-Laser etched, not stamped 2300 or maybe 2400 tube. I will fill with a hand pump and won't go over 1800. I believe this to be safe from what I've read here.
-Modded disco valve. Secured to tube with upgraded screws. I don't mind overkill here. I plan to use the shorter front valve half from a maximus. It's a little shorter and will allow more tube volume. Advise on TP size, given short barrel and my goals?
-PRod fill assy. Shorter than the disco, again for more tube volume. Anybody know if the Baker one is any shorter than the Prod one?
- No gauge or gauge port = more tube volume.
-Crosman steel or Baker alum. breech.
-Iron sites. Undecided on which ones.

Something like this build is what I have in mind. Found this on Mountain Air's site.

[avator]

Willie G. Stubbs might be interesting to you. Here's what I did.
https://www.gatewaytoairguns.org/GTA/index.php?topic=120751.msg1169321#msg1169321

[2K1TJ]

I remember reading that before. Cool little sidekick for sure! I love the use of the early grip frame.

Is the Ruger site made to fit dovetails or did you have to mod it, other that opening up the peep?

[avator]

That particular breech has the dovetail milled sideways. The Ruger peep too small for a snug fit. I cut a section of drill bit shank to fit in tightly. The Ruger peep has elevation adjustment and with the tight drill bit shank it also has windage adjustment just by tapping it from side to side. The peep also folds down out of the way to add a scope or red dot. If you zoom in on the second picture down you can see the drill bit shank.

[FuzzyGrub]

I like how short that is.     IMO, if you go to 10" barrel, that will be too big for "lawnmower" duty.   I built a Prod that is that big, ie 10" barrel with 1701P air tube.  It will fit the largest holsters available, just "too big" of an eye catcher.  I use a Walther 6" CP88, co2 repeater for lawnmower duty.  The snakes, moles, mice... are always moving and need follow-up shots.   

[rkr]

Short is good. I have a "BSA Ultra" bullpup with 10" barrel and total length of 54cm. 120-110 bar regulator setting and running at 14 fpe. 40 shots from a 230 bar fill. Perfectly backyard friendly with a shroud, although not as quiet as UK standard 12 fpe guns with LDC, There are P-rod bullpup kits you might be able to use ...

[avator]

Noise is not an issue where I live.... good thing too because Willie G. is .22 PB loud.