Today at the yard sale I picked up a Crosman "American Classic" model 1377 for ten bucks . It doesn't pump , and I think it's probably the cup
on the pump . Part is available for a few bucks and I'm wondering if I
should replace the rest of the seals and o-rings too . Is there anything
in there that I wouldn't have in a box of assorted o-rings ? I've also
seen "big bore" sleeves for the barrel/pump connection , looks like
something an enterprising old fart with a machine shop could duplicate ...
BTW , this pistol has the rotating sleeve instead of a bolt , cocks
by pulling on a knob on the back end of the pump sleeve . I have no idea
how old it is but it doesn't look exactly like the current model .
I've also seen "big bore" sleeves for the barrel/pump connection ,
looks like something an enterprising old fart with a machine shop
could duplicate ...
On 5/10/2025 3:24 PM, Snag wrote:
Today at the yard sale I picked up a Crosman "American Classic"
model 1377 for ten bucks . It doesn't pump , and I think it's probably
the cup on the pump . Part is available for a few bucks and I'm
wondering if I should replace the rest of the seals and o-rings too .
Is there anything in there that I wouldn't have in a box of assorted
o-rings ? I've also seen "big bore" sleeves for the barrel/pump
connection , looks like something an enterprising old fart with a
machine shop could duplicate ...
BTW , this pistol has the rotating sleeve instead of a bolt , cocks
by pulling on a knob on the back end of the pump sleeve . I have no
idea how old it is but it doesn't look exactly like the current model .
I resealed a 1st generation Model 1 in .22 I think they use the same
plenum and knock valve. My son might have his grandads 1377. Hold on.
Let me go look in his gun safe. I think they all have similar internals.
Would you have the seals? Its been a while since I had my Model 1
apart. I don't recall. I seem to think there might have been something different, but its not hard to take apart and look. I think there are
even some videos on YouTube doing it. Got a cup with a lid or a zip
lock bag to keep things in? Take it apart and look.
Yes, you should replace the seals and o-rings.
The cup is probably bad, but probably so are the seals on the plenum and knock valve. Works just like a PCP except it has a tiny little air reservoir. A spring loaded "hammer" slams into a pin opening the air
valve and dumping air into the barrel.
I've also seen "big bore" sleeves for the barrel/pump connection ,
looks like something an enterprising old fart with a machine shop
could duplicate ...
I have not seen that, but you absolutely could. Things have to have as
good of a finish as a hydraulic cylinder, but its possible.
The problem with a large volume pump is that I don't think you gain any
power after a certain point. Instead the air valve closes again without releasing all the air. In fact you can potentially get less power if
you over pressure the plenum because its harder for the hammer to open
the valve. That's kind of how an unregulated PCP works in fact. By
taking advantage of that principle. Anyway if you have the arm strength
to spare it might pump to optimum charge with fewer pumps. Or maybe I
don't know what you are referring to.
You can get more power out of a multi pump pneumatic if you increase the strength of the hammer spring and/or enlarge the plenum. Then more
pumps or larger pump "might" be give more usable power as long as the
plenum will hold it.
I just looked. The one my son got from his grandad is a 2100, but I
think they have almost the same guts.
On 5/10/2025 3:53 PM, Bob La Londe wrote:
On 5/10/2025 3:24 PM, Snag wrote:
Today at the yard sale I picked up a Crosman "American Classic"
model 1377 for ten bucks . It doesn't pump , and I think it's
probably the cup on the pump . Part is available for a few bucks and
I'm wondering if I should replace the rest of the seals and o-rings
too . Is there anything in there that I wouldn't have in a box of
assorted o-rings ? I've also seen "big bore" sleeves for the
barrel/pump connection , looks like something an enterprising old
fart with a machine shop could duplicate ...
BTW , this pistol has the rotating sleeve instead of a bolt ,
cocks by pulling on a knob on the back end of the pump sleeve . I
have no idea how old it is but it doesn't look exactly like the
current model .
I resealed a 1st generation Model 1 in .22 I think they use the same
plenum and knock valve. My son might have his grandads 1377. Hold
on. Let me go look in his gun safe. I think they all have similar
internals.
Would you have the seals? Its been a while since I had my Model 1
apart. I don't recall. I seem to think there might have been
something different, but its not hard to take apart and look. I think
there are even some videos on YouTube doing it. Got a cup with a lid
or a zip lock bag to keep things in? Take it apart and look.
Yes, you should replace the seals and o-rings.
The cup is probably bad, but probably so are the seals on the plenum
and knock valve. Works just like a PCP except it has a tiny little
air reservoir. A spring loaded "hammer" slams into a pin opening the
air valve and dumping air into the barrel.
I've also seen "big bore" sleeves for the barrel/pump connection ,
looks like something an enterprising old fart with a machine shop
could duplicate ...
I have not seen that, but you absolutely could. Things have to have
as good of a finish as a hydraulic cylinder, but its possible.
The problem with a large volume pump is that I don't think you gain
any power after a certain point. Instead the air valve closes again
without releasing all the air. In fact you can potentially get less
power if you over pressure the plenum because its harder for the
hammer to open the valve. That's kind of how an unregulated PCP works
in fact. By taking advantage of that principle. Anyway if you have
the arm strength to spare it might pump to optimum charge with fewer
pumps. Or maybe I don't know what you are referring to.
You can get more power out of a multi pump pneumatic if you increase
the strength of the hammer spring and/or enlarge the plenum. Then
more pumps or larger pump "might" be give more usable power as long as
the plenum will hold it.
I just looked. The one my son got from his grandad is a 2100, but I
think they have almost the same guts.
OH! DUH! Pistol. LOL. Sorry if some of my comments don't quite match up.
The principles are all the same.
On 5/10/2025 6:00 PM, Bob La Londe wrote:
On 5/10/2025 3:53 PM, Bob La Londe wrote:
On 5/10/2025 3:24 PM, Snag wrote:
Today at the yard sale I picked up a Crosman "American Classic"
model 1377 for ten bucks . It doesn't pump , and I think it's
probably the cup on the pump . Part is available for a few bucks and
I'm wondering if I should replace the rest of the seals and o-rings
too . Is there anything in there that I wouldn't have in a box of
assorted o-rings ? I've also seen "big bore" sleeves for the barrel/
pump connection , looks like something an enterprising old fart with
a machine shop could duplicate ...
BTW , this pistol has the rotating sleeve instead of a bolt ,
cocks by pulling on a knob on the back end of the pump sleeve . I
have no idea how old it is but it doesn't look exactly like the
current model .
I resealed a 1st generation Model 1 in .22 I think they use the same
plenum and knock valve. My son might have his grandads 1377. Hold
on. Let me go look in his gun safe. I think they all have similar
internals.
Would you have the seals? Its been a while since I had my Model 1
apart. I don't recall. I seem to think there might have been
something different, but its not hard to take apart and look. I
think there are even some videos on YouTube doing it. Got a cup with
a lid or a zip lock bag to keep things in? Take it apart and look.
Yes, you should replace the seals and o-rings.
The cup is probably bad, but probably so are the seals on the plenum
and knock valve. Works just like a PCP except it has a tiny little
air reservoir. A spring loaded "hammer" slams into a pin opening the
air valve and dumping air into the barrel.
I've also seen "big bore" sleeves for the barrel/pump connection ,
looks like something an enterprising old fart with a machine shop
could duplicate ...
I have not seen that, but you absolutely could. Things have to have
as good of a finish as a hydraulic cylinder, but its possible.
The problem with a large volume pump is that I don't think you gain
any power after a certain point. Instead the air valve closes again
without releasing all the air. In fact you can potentially get less
power if you over pressure the plenum because its harder for the
hammer to open the valve. That's kind of how an unregulated PCP
works in fact. By taking advantage of that principle. Anyway if you
have the arm strength to spare it might pump to optimum charge with
fewer pumps. Or maybe I don't know what you are referring to.
You can get more power out of a multi pump pneumatic if you increase
the strength of the hammer spring and/or enlarge the plenum. Then
more pumps or larger pump "might" be give more usable power as long
as the plenum will hold it.
I just looked. The one my son got from his grandad is a 2100, but I
think they have almost the same guts.
OH! DUH! Pistol. LOL. Sorry if some of my comments don't quite match
up. The principles are all the same.
I understand what you're saying . The larger part I was referring to
is the small sleeve between the barrel and the air reservoir . I'll take
it apart before I order any parts ... it doesn't look all that
complicated .
Are they worth a few bucks in parts ? I bought it mostly because it's
a Crosman and they're known for quality . And I didn't have an air
pistol ...
On 5/10/2025 4:17 PM, Snag wrote:
On 5/10/2025 6:00 PM, Bob La Londe wrote:
On 5/10/2025 3:53 PM, Bob La Londe wrote:
On 5/10/2025 3:24 PM, Snag wrote:
Today at the yard sale I picked up a Crosman "American Classic" >>>>> model 1377 for ten bucks . It doesn't pump , and I think it's
probably the cup on the pump . Part is available for a few bucks
and I'm wondering if I should replace the rest of the seals and
o-rings too . Is there anything in there that I wouldn't have in a
box of assorted o-rings ? I've also seen "big bore" sleeves for the
barrel/ pump connection , looks like something an enterprising old
fart with a machine shop could duplicate ...
BTW , this pistol has the rotating sleeve instead of a bolt ,
cocks by pulling on a knob on the back end of the pump sleeve . I
have no idea how old it is but it doesn't look exactly like the
current model .
I resealed a 1st generation Model 1 in .22 I think they use the same
plenum and knock valve. My son might have his grandads 1377. Hold
on. Let me go look in his gun safe. I think they all have similar
internals.
Would you have the seals? Its been a while since I had my Model 1
apart. I don't recall. I seem to think there might have been
something different, but its not hard to take apart and look. I
think there are even some videos on YouTube doing it. Got a cup
with a lid or a zip lock bag to keep things in? Take it apart and
look.
Yes, you should replace the seals and o-rings.
The cup is probably bad, but probably so are the seals on the plenum
and knock valve. Works just like a PCP except it has a tiny little
air reservoir. A spring loaded "hammer" slams into a pin opening
the air valve and dumping air into the barrel.
I've also seen "big bore" sleeves for the barrel/pump connection , >>>> >> looks like something an enterprising old fart with a machine shop >>>> >> could duplicate ...
I have not seen that, but you absolutely could. Things have to have
as good of a finish as a hydraulic cylinder, but its possible.
The problem with a large volume pump is that I don't think you gain
any power after a certain point. Instead the air valve closes again
without releasing all the air. In fact you can potentially get less
power if you over pressure the plenum because its harder for the
hammer to open the valve. That's kind of how an unregulated PCP
works in fact. By taking advantage of that principle. Anyway if
you have the arm strength to spare it might pump to optimum charge
with fewer pumps. Or maybe I don't know what you are referring to.
You can get more power out of a multi pump pneumatic if you increase
the strength of the hammer spring and/or enlarge the plenum. Then
more pumps or larger pump "might" be give more usable power as long
as the plenum will hold it.
I just looked. The one my son got from his grandad is a 2100, but I
think they have almost the same guts.
OH! DUH! Pistol. LOL. Sorry if some of my comments don't quite match
up. The principles are all the same.
I understand what you're saying . The larger part I was referring
to is the small sleeve between the barrel and the air reservoir . I'll
take it apart before I order any parts ... it doesn't look all that
complicated .
Are they worth a few bucks in parts ? I bought it mostly because
it's a Crosman and they're known for quality . And I didn't have an
air pistol ...
There are (or used to be) some guys who bought up junk and parted it
out, but they made a business of it. On an individual basis I think you
can get what you put into it out of it once you have it working, or
maybe a little more if its still pretty.
Does it have wood or plastic furniture? I think they were already
plastic when I was a kid. I knew a guy who shot birds with the 1377 out
at the McElhaney feed lots. I'm pretty sure his was plastic.
Plastic furniture . I did a little search and found out how to date
these . Mine was produced in June 1989 . I'll get it torn down at my
first chance , see what it needs . I can afford to spend a few bucks for >parts . I generally keep any kind of projectile weapon , never know what >you'll need !
| Sysop: | Keyop |
|---|---|
| Location: | Huddersfield, West Yorkshire, UK |
| Users: | 483 |
| Nodes: | 16 (4 / 12) |
| Uptime: | 229:31:57 |
| Calls: | 9,612 |
| Calls today: | 10 |
| Files: | 13,686 |
| Messages: | 6,155,205 |