Upgraded my 1366 Pest Gun

[Tack Driver 10]

Made the final parts and assembled the gun without incident.
Holds pressure so should get to chrony it in the morning when it's cooler.
Used duro 90 seals on the piston and valve.

Initial pressure test:
10 pumps 1600 psi
15 pumps 2100 psi
18 pumps 2500 psi

[antithesis]

Dang buddy, you making sure that front end ain't goin nowhere huh?

Loving that front plug though...I'd like to see stainless screws myself, but nobody ever accused me of good taste 😆

Edit: oh my God looks like they are...must be past my bedtime

[Tack Driver 10]

Dang buddy, you making sure that front end ain't goin nowhere huh?

Loving that front plug though...I'd like to see stainless screws myself, but nobody ever accused me of good taste 😆

Edit: oh my God looks like they are...must be past my bedtime

The screws are standard black oxide screws that are machined down to fit the tube.
The valve is pinned with 2 screws along with a SS washer pressed onto the back of the valve.
The HD pump link, brass piston and 90 duro seals completes the pump engine.
The idea is to minimize any movement and tube flex in a HD package that will last a long time.
The saying, "They don't make them like they used to." doesn't apply here.

Was able to gain 1/8" more stroke and lowered the valve volume by increasing the black spacer .050".

Ran the gun over the chrony this morning with 7.9 CPHPs.
The numbers in bold are the current results, the numbers in parenthesis are from the initial chrony on page 1.

05 pumps 574 (557) FPS  05.78 (05.44) FPE  0900 (0800) PSI
07 pumps 667 (650) FPS  07.80 (07.40) FPE  1200 (1100) PSI
10 pumps 762 (736) FPS  10.18 (09.50) FPE  1600 (1400) PSI
12 pumps 810 (790) FPS  11.51 (10.92) FPE  1800 (1600) PSI
15 pumps 873 (855) FPS  13.37 (12.80) FPE  2200 (1950) PSI
18 pumps 910 FPS 14.52 FPE  2500 PSI
20 pumps (920) FPS (14.85) FPE 2500 PSI

Got a nice bump up in power and made 2500 psi with 18 pumps vs 20 with the previous test.
With the current pump arm leverage factor and fatty wood fore grip the gun was extremely easy to pump even to 2500 psi.
It felt like I somehow was cheating the system, like playing a video game using the cheat code....LOL
To put this into perspective a 2100 would need a 13" pump arm vs the 11" it has from the factory.
A 1400 would need a 21" pump arm vs the 13" stock pump arm.

Since a 2100 tube was used as the base for this gun, there is room for another 1/2" of stroke with a shorter valve.
That would increase FPS by 25 and a non choked barrel would add another 20 FPS or similar performance to a hot rod 2100.

[antithesis]

Dang buddy, you making sure that front end ain't goin nowhere huh?

Loving that front plug though...I'd like to see stainless screws myself, but nobody ever accused me of good taste 😆

Edit: oh my God looks like they are...must be past my bedtime

The screws are standard black oxide screws that are machined down to fit the tube.
The valve is pinned with 2 screws along with a SS washer pressed onto the back of the valve.
The HD pump link, brass piston and 90 duro seals completes the pump engine.
The idea is to minimize any movement and tube flex in a HD package that will last a long time.
The saying, "They don't make them like they used to." doesn't apply here.

Was able to gain 1/8" more stroke and lowered the valve volume by increasing the black spacer .050".

Ran the gun over the chrony this morning with 7.9 CPHPs.
The numbers in bold are the current results, the numbers in parenthesis are from the initial chrony on page 1.

05 pumps 574 (557) FPS  05.78 (05.44) FPE  0900 (0800) PSI
07 pumps 667 (650) FPS  07.80 (07.40) FPE  1200 (1100) PSI
10 pumps 762 (736) FPS  10.18 (09.50) FPE  1600 (1400) PSI
12 pumps 810 (790) FPS  11.51 (10.92) FPE  1800 (1600) PSI
15 pumps 873 (855) FPS  13.37 (12.80) FPE  2200 (1950) PSI
18 pumps 910 FPS 14.52 FPE  2500 PSI
20 pumps (920) FPS (14.85) FPE 2500 PSI

Got a nice bump up in power and made 2500 psi with 18 pumps vs 20 with the previous test.
With the current pump arm leverage factor and fatty wood fore grip the gun was extremely easy to pump even to 2500 psi.
It felt like I somehow was cheating the system, like playing a video game using the cheat code....LOL
To put this into perspective a 2100 would need a 13" pump arm vs the 11" it has from the factory.
A 1400 would need a 21" pump arm vs the 13" stock pump arm.

Since a 2100 tube was used as the base for this gun, there is room for another 1/2" of stroke with a shorter valve.
That would increase FPS by 25 and a non choked barrel would add another 20 FPS or similar performance to a hot rod 2100.

Don't make em like they used to?

*(&^, I don't think they ever made em like that😁

[Tack Driver 10]

What's the next logical move?

My "Chubby" gun is based on a fat (hence the name) 3/4" id MK-177 tube with a similar 4" stroke.
A 3/4" id by 4" stroke is equivalent to a 5/8" id by 5 3/4" stroke.
It's 22 cal with an 18" Air Force (LW) barrel, PRod trigger and is super accurate.
Gets 700 FPS with 10 pumps and 800 FPS with 15 pumps using 14.3 CPHPs.
It's does 915 FPS with a 24" Crosman barrel and 20 pumps.

Need to mod this gun similar to the 1366 with a modified NOS 766 pump link and gauge.
Would like to see 740 and 840 FPS with 10 and 15 pumps with an easy pump effort.
Might be a good project heading into winter.

[antithesis]

What's the next logical move?

My "Chubby" gun is based on a fat (hence the name) 3/4" id MK-177 tube with a similar 4" stroke.
A 3/4" id by 4" stroke is equivalent to a 5/8" id by 5 3/4" stroke.
It's 22 cal with an 18" Air Force (LW) barrel, PRod trigger and is super accurate.
Gets 700 FPS with 10 pumps and 800 FPS with 15 pumps using 14.3 CPHPs.
It's does 915 FPS with a 24" Crosman barrel and 20 pumps.

Need to mod this gun similar to the 1366 with a modified NOS 766 pump link and gauge.
Would like to see 740 and 840 FPS with 10 and 15 pumps with an easy pump effort.
Might be a good project heading into winter.

In my opinion?

Up the ante to 24" af barrel, and maybe a hair more valve volume provided the room? Slightly lower pressure maintaining easy pumping, but enough barrel to capture the magic...but again, no accounting for taste.

Does it gotta stay stubby? I'm told six inches makes a difference 😆

[Tack Driver 10]

What's the next logical move?

My "Chubby" gun is based on a fat (hence the name) 3/4" id MK-177 tube with a similar 4" stroke.
A 3/4" id by 4" stroke is equivalent to a 5/8" id by 5 3/4" stroke.
It's 22 cal with an 18" Air Force (LW) barrel, PRod trigger and is super accurate.
Gets 700 FPS with 10 pumps and 800 FPS with 15 pumps using 14.3 CPHPs.
It's does 915 FPS with a 24" Crosman barrel and 20 pumps.

Need to mod this gun similar to the 1366 with a modified NOS 766 pump link and gauge.
Would like to see 740 and 840 FPS with 10 and 15 pumps with an easy pump effort.
Might be a good project heading into winter.

In my opinion?

Up the ante to 24" af barrel, and maybe a hair more valve volume provided the room? Slightly lower pressure maintaining easy pumping, but enough barrel to capture the magic...but again, no accounting for taste.

Does it gotta stay stubby? I'm told six inches makes a difference 😆

I see where you're going with this.
What red blooded American male would turn down an extra 6", whether they could use it or not ....LOL
 
Realistically, I like the form vs function of the gun as is.
It's 39" long with the 18" barrel and reasonably quiet with the 6" can.
A 24" barrel without the can would be the same length but be very loud.
A reasonable compromise is to cut down the 24" to 21" and have a 42" gun with a can like my 1366.

It's legal to shoot where I am but the neighbors get restless and I've been visited by the Sheriff on a few occasions.
Nothing they can do since I'm a responsible shooter (most of the time).
Not a problem since I went covert and made a bunch of silencers for my shooters.

I have a nice piece of 2" square black walnut that I can use for the wood pump grip similar to the 1366.
It would match up nice with the black walnut and red oak stock currently on the Chubby.

[mav72]

What's the next logical move?

My "Chubby" gun is based on a fat (hence the name) 3/4" id MK-177 tube with a similar 4" stroke.
A 3/4" id by 4" stroke is equivalent to a 5/8" id by 5 3/4" stroke.
It's 22 cal with an 18" Air Force (LW) barrel, PRod trigger and is super accurate.
Gets 700 FPS with 10 pumps and 800 FPS with 15 pumps using 14.3 CPHPs.
It's does 915 FPS with a 24" Crosman barrel and 20 pumps.

Need to mod this gun similar to the 1366 with a modified NOS 766 pump link and gauge.
Would like to see 740 and 840 FPS with 10 and 15 pumps with an easy pump effort.
Might be a good project heading into winter.

Ooo That’s even better. I’m liking it a lot now.

Function is a big deal for me also. I like my longer airguns but I prefer a shorter length when lugging it around the backyard.

[Tack Driver 10]

How silly of me to leave out a very important feature of the new wood pump arm.
It's the new and exciting plug and play bumper technology and will keep you stealthy as you pump to your hearts content.
This one is a duro 50 poly bumper........looks like a gummy candy....LOL

[antithesis]

How silly of me to leave out a very important feature of the new wood pump arm.
It's the new and exciting plug and play bumper technology and will keep you stealthy as you pump to your hearts content.
This one is a duro 50 poly bumper........looks like a gummy candy....LOL

Ooohh..I want! Is it prefabricated or lemme guess.... you made it like every thing else?

[Tack Driver 10]

How silly of me to leave out a very important feature of the new wood pump arm.
It's the new and exciting plug and play bumper technology and will keep you stealthy as you pump to your hearts content.
This one is a duro 50 poly bumper........looks like a gummy candy....LOL

Ooohh..I want! Is it prefabricated or lemme guess.... you made it like every thing else?

Right, made it from 3/8" red poly round stock.
Think of it as a cherry flavored muffler for your air gun.

[RATSLAYER]

Can a max smoke valve be purchased? Looking to increase power in my 1300KT

[Tack Driver 10]

Can a max smoke valve be purchased? Looking to increase power in my 1300KT

The Max Smoke valve requires modification to the pump tube and trigger frame.
The forward mounting screw for the trigger frame is moved back and the tube drilled and tapped to receive  the screw.
I tapped the tube for a 6-48 gun screw, the regular screw is a dummy that is glued in.
This is required since the check valve is moved forward.

Fresh off the press, there's a new version of the Max Smoke Valve.
It's called the Max Smoke Pro, soon to be released.
Here's an artists rendition and you can see the progression from the stock valve to the Pro.
It "gets the junk out of the trunk" making the exit path shorter and more efficient.
Here's a sneak peek, look for it soon at a forum near you.....LOL