Canadian Airgun Forum

While thinning the herd I recently came across a couple of guns I didn't even know I had...an old "backpacker" in .22 and an "American Classic" 1377.

Both are all there and shoot, but are weak. I dont have much direct experience with these guns.

I am going to rebuild them but have a question concerning flat top piston's.

I only see a piston-valve kit for the 1377...does this work in the 1322 as well? My gut says "yes" but not sure.

The piston is adjustable and instructions say to adjust it so it just kisses the valve at 3/4 pump arm stroke...is the only way to do this assemble, check, disassemble, adjust, reassemble?

I've also got a tube coming as I plan to turn the 1377 in to a carbine and dont need legal headaches.

I do have some related experience with my 2240, steel breech, LW barrel, hammer spring, walnut grips etc, but of course it is a different gun.

Thanks

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When the 425-hp "street Hemi" version hit the street in 1965, it was akin to taking an M230 chain gun to an arcade shooting gallery
Peter

They're the same guns minus the barrel, bolt probe and O ring are the only things different. Yes a 1377 FT kit will fit in a 1322 and vise versa being they use the same piston and valve.

For the piston adjustment. All you need to remove is the pivot pin that holds the arm and front band in the maintube and make your adjustments.

Sounds straightforward, thank you.

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When the 425-hp "street Hemi" version hit the street in 1965, it was akin to taking an M230 chain gun to an arcade shooting gallery
Peter

Some tips for you:

While adjusting the piston, you can use a 3/16'' drill bit stem in place of the pump arm pivot roll pin, much easier and fast.

Crosman pump rifle tubes don't have breech screw and grip holes, you'll need to drill (and thread, for the front breech screw) new holes. Also said tubes are longer at the rear, you'll need to shorten your new tube to be able to install the breech and grip frame.

If you use a longer barrel, a 2289/760 barrel band could be used. It also is a good opportunity to convert to a metal barrel band/solid steel pump arm pivot pin.

When I installed a rigid piston on my 1377, I adjusted it so the arm just locked at the stroke end, it was a bit less than 3/4''. Also, as a ''maniac only'' mod, you can have the rear of the valve machined to install a SS backing washer to avoid that the step in the tube dig into the valve.

HTH

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

There are a couple of threads on pumper tube conversions on the mods and repair page by Wes B. and myself that go into the finer details. 2100/2200 or 1760 series tubes would be your best economical bet.

Airmec- interesting mod on the valve. I simply pressed a steel wire friction ring over the end of my valve, and it seems to work. IIRC, it came from a set of luggage keys- a darn lucky tight fit.

-D.S.

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"Ain't no half-way"
-S.R.V.

Thanks Doc! Your mod seems to be easier though

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

If you want more power per pump you can cut a step in the back of the valve as well to move the valve back over the stop dent in the tube and then keep the back end of the tube as is without cutting it off (when using a 760/2100 tube. You can also cut the front of the valve off flat right at the back of the screw hole and machine a new oring slot if you have the tools to do so. This will give you even more air per pump stroke. Bob Sterne has great threads and also shared on Doc and my threads some of those details with pictures.

Sent from my SM-G930W8 using Tapatalk

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Website: https://airgunarcheryfun.ca/

Some great tips and I've skimmed those threads before. Now I've actually got some of the guns and parts I'll re-read with renewed interest.

Thanks

_________________
When the 425-hp "street Hemi" version hit the street in 1965, it was akin to taking an M230 chain gun to an arcade shooting gallery
Peter