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Jim Gillilan's Custom 1322 Carbine

Jim Gillilan's Custom 1322 Carbine w/Custom Stock

Here's one I'm especially proud of and is modded all over, doing 12fpe at 15 pumps.
Stock is Teak from Thailand and super light weight 1322 Carbine!

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Re: 1322 PCP - the skeletonized valve doesn't leak anymore...

April 22 2017 at 9:46 PM

WyoMan  (Login WyoMan)
Crosman Forum Member
from IP address 65.131.49.108

finally. What a pain. Lots of de-burring but the fix was using the right O-rings - cast urethane, size 013 to seal the valve with the tube (for the cut-out area). I also cut the o-ring grooves a little deeper... only a few thou

[linked image]

[linked image]

Pumped it up - took 17 pumps to fill the valve. Before skeletonizing it was only 9. It's been holding air for two days now so I'm getting ready to tune and test. Thanks -

Wyo



    
This message has been edited by WyoMan from IP address 65.131.49.108 on Apr 22, 2017 9:50 PM


 
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Bio
(Login Biohazardman)
Moderator
71.236.167.69

Re: 1322 PCP - the skeletonized valve doesn't leak anymore...

April 23 2017, 4:27 AM 

Lots more volume is good. Yup right depth and width of cut to match the o-rings is a big deal and so nice when you get it right congrats. Makes me think I should fix the leak in mine but just got a couple new powder burners and have been saving .22 rounds for many years. So I have enough rounds to shoot for awhile months maybe even years? Can you say slacker? Actually like the song says I make them look like overachievers these days! So I am good for something anyway. ;^) Just not right now. ;^) Glad you got rid of the leaks I really hate them. Now I have to get back to slacking.
I used to have a life. But now I have the forum. I am a sick man?

[linked image]

 
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WyoMan
(Login WyoMan)
Crosman Forum Member
65.131.49.108

The small o-rings (1/16" cross -section)

April 23 2017, 7:04 PM 

don't want to 'skate' as well over the tube holes as the 3/32" CS o-rings.  Six total holes to navigate... I used this to help coax them thru:

[linked image]

Thanks -

Wyo


 
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Bio
(Login Biohazardman)
Moderator
71.236.167.69

Re: The small o-rings (1/16" cross -section)

April 23 2017, 10:01 PM 

Even when one has removed the burrs from the holes on the inside of the tube they are still very sharp. I think it was TKO that suggested a Dremel ball bit, not the one pictured, but you get the drift, manipulated inside the tube till you can get the shaft out of the hole then twisted by hand to break the corners of the holes. A small screw with a countersink head and a piece of 400 or so sandpaper taped or glued to prevent slippage turned by hand or with a drill will do the same. I slacked and did not take the time to do this on my last project cuz I was in a hurry for some unknown reason so got the deserved results of the dreadful slow leakage of pressure from the tube. So being in such a hurry I just left it lay on the floor for the last two months while I pondered the reason for my existence. ;^)

[linked image]
I used to have a life. But now I have the forum. I am a sick man?

[linked image]


    
This message has been edited by Biohazardman from IP address 71.236.167.69 on Apr 23, 2017 10:15 PM


 
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WyoMan
(Login WyoMan)
Crosman Forum Member
65.131.49.108

Always nice to see ideas and

April 24 2017, 6:19 PM 

tool gizmo inventions - thanks!

I'll sometimes use this ensemble (if the reach isn't too far):

[linked image]

works fast too - spin CW then CCW

Wyo


 
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Scot Laughlin
(Login classicalgas)
Crosman Forum Member
50.159.8.234

Great news!... and it sounds like you gained significant volume

April 23 2017, 11:03 AM 

Looking forward to test numbers.

 
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WyoMan
(Login WyoMan)
Crosman Forum Member
65.131.49.108

Thanks, Scot... you were right about the thread pitch..

April 23 2017, 7:11 PM 

on the RVA. It's very sensitive... results below. thanks again -

Wyo


 
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James Perotti
(Login jpsaxnc)
Crosman Forum Member
71.71.83.71

Hi Wyo, Do you have a way to gauge the pressure,

April 23 2017, 1:44 PM 

when you do the initial fill, and the recharge pumps between shots?

 
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Steve in NC
(Login pneuguy)
Crosman Forum Member
162.198.201.47

Didn't Wyo say he can feel when piston/valve contact disappears...

April 23 2017, 5:13 PM 

...and uses that as his "stop-pumping" pressure indication?

 
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WyoMan
(Login WyoMan)
Crosman Forum Member
65.131.49.108

Hi James, Steve is right...

April 23 2017, 7:20 PM 

The pressure is indicated by setting the piston length to make contact with the valve. In this gun, it was when the forearm is 21 mm from closing. You stop pumping when the piston doesn't contact the valve.

The force on the piston, and the resulting strain, are directly proportional to the accumulated valve pressure. It works pretty well. I got the idea from Steve's "tell-tale" indicator. It's kind of spin-off, thanks

Wyo


 
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WyoMan
(Login WyoMan)
Crosman Forum Member
65.131.49.108

Some tuning and testing...

April 23 2017, 7:51 PM 

The extra volume did help, no doubt, but I'm now facing another reality... I think - small pump volume. There's probably only so much you can do with 1.1 cubic inch at 80% atmosphere. But still, it has better performance (efficiency) than anything else I've got... and with a 12" barrel.

 [linked image]

With 4 recharge pumps it made 5.7 fpe, with 3 it was 4.7. The prior version (smaller valve) did 5.2 fpe with 4 recharge pumps. I am surprised and impressed with the ES and accuracy. It makes a nice 10m pistol.

Some other notes...I cranked-in the RVA as far as it would go and got 578 fps or 11.8 fpe from a full charge. It didn't empty the valve but I'm not going to re-spring to dump 17 pumps. I took a second shot when it was tuned for 4 recharge pumps and got 404 fps... 3 fps higher than the average first shot. That's pretty nice. There are lots of ways to tune these and I'm still getting my feet wet...

One more gratuitous pic (to make sure it happened) happy.gif

[linked image]

Wyo


 
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Bio
(Login Biohazardman)
Moderator
71.236.167.69

Re: Some tuning and testing...

April 23 2017, 10:11 PM 

At seven-thousand feet there is far less oxygen so it is important to make things shiny so you can see them better with blurred vision? ;^) I remember my chest muscles being sore for a week or two when I was first werqing up there and then coming home to near sea level many months later to notice I needed to breath every now and then but not all that often. Crazy what we can get used to.

Impressive job on the build thanks so much for sharing.
I used to have a life. But now I have the forum. I am a sick man?

[linked image]

 
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WyoMan
(Login WyoMan)
Crosman Forum Member
65.131.49.108

Thanks, Bio -

April 24 2017, 6:50 PM 

hey, I've backed off the reflectivity a bit happy.gif

Wyo


 
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James Perotti
(Login jpsaxnc)
Crosman Forum Member
71.71.83.71

Those strings are flat, It looks like the mecanical repetability

April 24 2017, 5:36 AM 

of the gun is very good. And your pressure gauging method sure seems to work well.


    
This message has been edited by jpsaxnc from IP address 71.71.83.71 on Apr 24, 2017 5:43 AM


 
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WyoMan
(Login WyoMan)
Crosman Forum Member
65.131.49.108

The pivot is reinforced and the valve is pinned..

April 24 2017, 6:37 PM 

on top, opposite the bottom screw. I think that the added rigidity is the key to keeping the strain elastic (repeatable) and not permanent.

I shot it today with the 3 recharge setting and it was all over the place. Some bolt lube may have got down onto the hammer and affected the hammer energy. The spring setting is really light for 3 recharge pumps... I may go back to 4. This is a pretty complex platform (for me anyway) but I like the results that it delivers. thanks-

Wyo


 
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