Aluminum Flat Top Valve & Piston Kit
For Crosman 1322 1377 2289 P1322
2021 UPDATE: The piston now features two o-rings for better
compression. Looks a lot more professional, too.
MAY 2021 UPDATE x2: A solid brass
piston is now available. It's fancier. It's heavier. It's bling that only
you know is inside...?
APRIL 2023 UPDATE:
Crosman 362 Flat Man's Pack now
APRIL 2023 UPDATE x2:
Adjustable Pistons now
- The Flat Top upgrades are immensely
popular with Crosman pumper enthusiasts. The idea is that by giving the
gun a larger air reservoir, you can do more work per pump, resulting in
the same shot velocity with FEWER pumps. Or, increase velocity with the
same number of pumps over OEM.
- You can buy just the Flat Top Valve,
just the Piston or the Complete Kit.
- Note that you should not install just
a Flat Piston with an OEM valve. The gun won't cock completely and will
- You can, however, install just the
- But the smart move is to install the
- Want even more mods? Consider the
Flat Man's Pack, which is the
Flat Top Kit + Power Spring + Max Flow
- The Flat Top Valve is an OEM Crosman
valve that has been heavily modified.
- First, we put it on the mill and angle
the exhaust so the escaping air doesn't have to make a hard 90° exit.
- After that, we straighten up the
exhaust hole with a nice six-fluted bit.
- Then, we flatten the face to allow
more air to be pressurized per pump.
- Finally, we remove as many machining
marks as we can to make a perfectly smooth exterior.
- And, of course, the valve is cleaned
and polished prior to reassembly with BRAND NEW o-rings.
- This is the Flat Top Piston. It is
7075 aluminum milled from scratch. A solid brass version is available,
This is the older single o-ring style. All
shipments will feature double o-ring pistons as shown below.
- And here is the complete kit.
- Here is the kit with the brass piston.
While you can buy the
valve-only and piston-only individually, they're not designed to be used
with competitor's products, nor will they work with non-flat parts.
The Flat Valve won't work with an OEM Piston and vise versa. But, they are
available, if you have a specific project you want to accomplish.