CR180 breech seal

CR180 breech seal

Joined: February 11th, 2011, 2:00 am

April 14th, 2012, 12:36 pm #1

My Crosman 180 shoots great, very accurate and low 600's on a warm day. Still, I sometimes notice a slight blow-by at the breech seal. I put in a poly tubing piece cut to .155". Thought it was slightly longer than the stock gasket. Is this minor leakage to be expected of these guns?
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Joined: February 5th, 2011, 5:49 pm

April 14th, 2012, 7:51 pm #2

bolt? or at the transfer port, where the barrel meets the CO2 tube? If its at the transfer port then the poly-tube you put in might be too long, and is bent over blocking air passage. I would say that its not to be expected if everything is installed properly. Tho 600s are good, Im sure once the blow-by issue is resolved you'll see higher numbers. I would recommend taking the barrel off and checking the poly tube, easy enough to just check it out. It only really needs to be a fraction longer than the height of the port itself to make a good seal

good luck, and give an update pls!

andy
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Joined: February 11th, 2011, 2:00 am

April 14th, 2012, 9:34 pm #3

The original gasket measured .150" I made the new one .155" in length, apparently I need to try one just a touch longer, maybe .160".
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Joined: February 5th, 2011, 5:49 pm

April 14th, 2012, 11:31 pm #4

I had some trouble when I made mine a little too long, and it kinda folded over a bit causing some air to get redirected
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Joined: February 11th, 2011, 2:00 am

April 15th, 2012, 1:44 pm #5

I wasn't able to get a good seal with the rubber gasket that came with the kit I bought. Could it have been to short? I'm going to shoot this gun as it is for now. (I have some 1/4" nylon tubing, wonder if anyone has tried that?)
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Joined: May 17th, 2004, 4:36 pm

April 15th, 2012, 3:53 pm #6

On some rifles, the stock transfer port consists of a metal o-ring/washer in the air tube that the rubber transfer tubing sits on top of. If you use 1/4" icemaker tubing, you need to get rid of that o-ring and the tubing will fit right into the recessed hole in the air tube. You may need to counterskink a 1/4" hole into the barrel/breech for the other end of the tubing to grab onto. Nothing deep, maybe 1/16" or so. If you do this, you will end up with a considerably longer transfer tube than the stock one.

"but I'll be needin' that gun, fer squirrels and such."
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Joined: February 11th, 2011, 2:00 am

April 17th, 2012, 12:25 pm #7

I just cut a piece of tubing and replaced the old gasket. I don't think I am equipped to go drilling or grinding on this gun, I'm afraid I'll mess it up for good. Nope, I'll just leave it as is for now, maybe try a slightly longer gasket when and if I open it up again.
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