Flub's General Discussion - Gamo Challenger

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Gamo Challenger

Printed From: Kiwi Airgunners
Category: General
Forum Name: Flub's General Discussion
Forum Description: General discussion goes in here.
URL: www.kiwiairgunners.co.nz/forum_posts.asp?TID=350
Printed Date: 19 Apr 2025 at 1:01pm
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Topic: Gamo Challenger

Posted By: Novagun
Subject: Gamo Challenger
Date Posted: 23 May 2017 at 3:56am

I have had the Challenger for well over a year and it has had a lot of use. It is not a full Challenger anymore. It is a CFX with a fancy stock and a gas ram. After a lot of tinkering it has turned out to be very accurate especially with the Airgunghandi forehand grip/rest. Trouble is the gas ram is leaking oil and has lost a lot of power. Still very accurate at 12 metres but down on power.

New gas ram maybe or perhaps a good old wire spring or maybe just park it for a while. From my limited experience I would say that a gas ram is no better than a wire spring just a little different.

I think a spring conversion just to see what it is like.

The Gamo CF range can be very good rifles. It takes a lot of mucking around so why can't Gamo do it right the first time round and produce a really good gun out of the box.

Rick Eusler says gas ram is just hype and I think he is right.

he is a pretty down to earth airgun tester without the american hyperventilating. He gets to play with a lot of different guns.

Replies:

Posted By: nunga
Date Posted: 23 May 2017 at 8:03am

You say it is leaking oil? are you sure it is from the ram? Oil is a lot thicker than air, if oil is leaking out of the ram there will be no pressure in the ram because the gas is a lot thinner. If the seals are that far gone there is no way the gun would even fire. This may sound strange but are you sure the oil is not coming from the synthetic stock? I have seen synthetic stocks leak oil from cracks in the stocks and shortly after the brake, see the technical section ( think i posted a photo of one that did the exact same thing.

I would be looking at the main piston and both the piston and breech seals before you go replacing the ram with the spring.

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2nd place HP springer - WFTF World Championships 2014

Posted By: Novagun
Date Posted: 23 May 2017 at 8:37am

yes Nunga, I take your point. I was running the rifle with a modified hydaulic seal on the piston. Just turned down to fit the bore of the cylinder. I thought I could improve on that so I turned down another Y seal, I think they call them. This time I worked a lip into the circumference so it became a parachute seal.

It was when I had the gun apart that I noticed that the volume behind the piston seal was wet. A back wetness of oil and moly. I have never put any oil in that part. Must be silicone oil because there is no dieseling but whatever it is is miscible with ordinary moly grease and I use very very little. Grease then wipe out to clean. A touch on the rear end of the . That is enough. Piston seal edge is lubricated with a little Die electric grease.

When I first dismantled the gun when I bought it there was some clear oil under the rotary breach. I cleaned all that out. The piston arm and the seal on the ram looks moist and that is what makes me think the ram is leaking.

Definitely not coming from the stock. That is hefty and of beach or similar.

I have another non leaking ram here that belongs to Davey. Might just pop it in for a few shots and see what happens.

Might try a new Gamo seal and see what that does.

Posted By: xyon
Date Posted: 23 May 2017 at 10:26am

I can think of one way you would get oil and not lose all the gas. Assuming the ram piston is facing forward and you have stored the rifle barrel down, the gas will be pressing on the oil and may have pushed a bit out the seal over time.

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My favourites
springer - Diana 52
PCP - FX Wildcat III

Posted By: Novagun
Date Posted: 23 May 2017 at 1:13pm

Yes that could happen but the rifle spends most of its time sitting on its butt. (Not like me) If it is losing gas why has it not lost it all or is that something that I to look forward to.

I really like the Gamo ICT system and the SAT triggers. The much butchered CFR that I borrowed was nice and maybe I could have got it to shoot nicely but because it belonged to someone else I could not do much to it.

Haven't come across a CAT trigger yet but maybe one day,. That might be another step up the social chain.

No rainy days in the offing to it will have to wait.

Posted By: Pauly5
Date Posted: 23 May 2017 at 2:51pm

As long as you aren't sitting around on your butt loosing gas Nova.

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Posted By: Novagun
Date Posted: 28 May 2017 at 3:23pm

Bit miserable today so I pulled the Challenger apart and put the old hydraulic seal back on the piston. Power is back to normal. The seal with the lip worked into it looked good but the actual lip was less than 1 mm across.

Jim from Airgunworld made comment that the lip needed to be substantial and he was right.

Posted By: Pauly5
Date Posted: 29 May 2017 at 3:59am

That's good. Nothing like fixing stuff.

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