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nonconformist · Member

Just a quick note.

I just bought a used 1077 the other day. It leaked from the CO2 inlet from the first cartridge. It looked like there was no o-ring or anything in there but upon further inspection, the end seal was yellowish-clear and there was one in there, but it was cracked and dried out. Putting in one or more 1/8", 1/16" thick rubber o-rings improved it and made it possible to shoot up to about 25 or 30 rounds per powerlet but it still was leaking.

I searched for a suitable replacement part locally since my kids and I have a camping trip this weekend and I wanted the gun to work by then. No hopes that Crosman is going to get my new part to me in time. The seal is Crosman part number 38-128 "End Seal" and it is $1.15 plus about $5 s/h from Crosman. It is almost exactly the same dimensions as a 1/16" ID bibb washer that you would use in a faucet. In fact a rubber bibb washer, matched to the same ID and OD size and 3/16" thickness would probably work in place of the Crosman part. Unfortunately I was unable to find a bibb washer in any material other than urethane which is way too hard to work in this application (you would never get the CO2 to puncture).

A 1/8" thick, .25" ID rubber o-ring might just work in a pinch.

If anyone knows of a more commonly-available part that will work, I am all ears. These seals are used in a variety of Crosman and other CO2 airguns and paintball guns. I am frankly surprised that they are not available at sporting goods shops that sell CO2 and paintball guns.

The rifle I bought had about 300-400 rounds through it since new. I certainly hope that this seal is not an item with a 300-400 round lifetime. I ordered two just in case. However I am hoping to put more like 500 rounds a month through my 1077. I don't want to have to change this seal every month! I would think the refrigerant effect of the expanding CO2 is likely very hard on this seal and is the main cause of cracking.

broommaster2000 · Moderator

There should be some kind of lubricant that will help keeping the seals good, if I recall well. Neutral

I'm not sure which one, but there are probably other forum members to help you on that.

You see, CO2 is pretty darn cold when it's used so quickly, like in the 1077. Mr. Green

AirGunEric · Site Admin

Someone had mentioned in another post related to your 1077 that a bit of oil (non-detergent) on the end of the caplets when you install them will help keep things from drying out.

If using replacement seals- be sure they are not going to break down if in contact with petroleum-based products- Crosman puts a bit of oil in their Co2 cartridges which lube internal parts like the valve- and it will get on o-rings and seals over time- so they use o-rings not affected by petroleum-based products.

And no- that seal breaking down is not really a common "problem"- perhaps this rifle had been stored for many years and/or the prior owner always screwed the Co2 caplets in as tight as possible, flattening out and tearing the seal a bit.

nonconformist · Member

Well I only have the previous owner's story to relate. The previous owner is a teen-age kid. He says he got the gun for Christmas "a few years ago" and that he only shot it about 10 times, witnessed by the remaining 15 CO2 cartridges in the 25-pack that was given to him with the gun.

Looks like grandpa or someone gave the kid an air rifle that he had little interest in owning. The whole thing was a package deal, including 300 Gamo airgun targets, 25 CO2 cartridges, 4 500rd packs of pellets, the rifle, red dot scope and a hard carrying case. What was left was 3 unopened boxes of pellets, one box with about 100 left, 15 out of the 25 CO2 cartridges, and one box of Gamo targets with a few missing from the box plus two more unopened boxes. That with the rifle, case, accessories. The warranty registration card was included. The rifle had an empty CO2 cartridge in it when I got it. So it looks like the kid shot about 400 rounds using 10 CO2 cartridges and a couple of targets. This supports his story.

There was no Pellgunoil in the setup, which may explain the early seal failure. Along with the manual, a shrink-wrapped VHS video on how to shoot air rifles, and unsent warranty registration card, there was a Crosman 2003 accessories catalog. My suspicion is that this gun was new in 2003 or 2004 and probably sat with an empty or part-empty CO2 cartridge in it for the past couple of years, so the seal was smashed flat.

I just want it to work for plinking. I will probably shoot about 100-500 rounds a month along with my kids. The only mods I plan to do on the rifle are to re-crown the barrel, whip up a barrel stabilizer, and replace this seal. Hopefully it will go for a long while like this.

Which other parts are common wear items? If I want to be plinking with this gun for years to come, which parts should I go ahead and stock up on? I ordered two new end seals, but maybe I should get some more, plus a replacement valve?

Alstone · Moderator & Site Supporter

To lube it just use silicon oil, put a drop on the end of each capsul when loading, all you need to do is stop the refrigerant from penertrating the seals and silicon will do that for you.

Al

yourdaddyjoe · Supporting Member

I think I saw that ad... Did it have a scope on it?

Duh.... I just re-read it... Red Dot...

Sacramento Craigslist???

AirGunEric · Site Admin

Other than the end seals you have on order, if you lube it regularly and don't plan to try and funk with the valve, there really shouldn't be any other parts that would fail regularly/frequently.

dummyracer36 · Senior Member

my 1077 started leaking from the end seal recently also, didnt bother looking for a substitute, just ordered a few from crosman. but i dont plan on keeping it as a powerlet gun for much longer, will be converting it to use an avanti cylinder. its OD is the same as the tube thats already there.

http://www.pyramydair.com/cgi-bin/zoomed_model.pl?model_id=334&type=A

once i burn thru my remaining powerlets i'll do the conversion, and finish inletting the thumbhole stock i've been working on for it.

http://rifle-stocks.com/laminated_blanks.htm

got the target style blank in black and grey

installing a 24" barrel in it as well, just finished cutting the retaining ring on it. and making a stainless shroud that will hopefully capped by a muzzlemac break.

out of curiosity, anyone know of a valve from another gun that would work in it?

AirGunEric · Site Admin