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Author Topic: Gamo G Challenger  (Read 4066 times)

Offline Novagun

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Gamo G Challenger
« on: July 28, 2016, 12:34:12 PM »
Gamo G Challenger.


Mr Gamo had a selection of demonstration guns at the WAG shoot last Sunday.
Among them was the IGT G Challenger, a funny looking thing with a pale finished beach stock. I had a couple or more shots and decided I wanted one. Out came the credit card and as soon as I got home and walked in the door – “What did you buy?’ She had been sorting out the bank card on the computer and up popped the bill. She was not pleased but I am so that equals Zero.

The Challenger is really the old CF action that is a BSA but with a gas spring. The same action appears on the CF 30, the CFX the CFR and the CF Big Cat that was made exclusively for Hunting and Fishing. The metal work is not up to Theoben standard by a long shot but still very acceptable.

The Challenger has adjustable butt plate and adjustable cheek piece.  The pistol grip is of the upright style and a good comfortable handful. The forestock is quite bulky but it very quickly establishes itself as a very comfortable stock. The most comfortable of any mid range rifle I have handled and probably the best of any common production gun. It really suits tall people and the look of it grows better with time. It is obviously made on a computer controlled router but very tidy. It is noticeably heavier than the synthetic stocked CFX or CFR. (4.3 kgs with scope compared to 3.7 for the CFX) It is quite a big gun but still light enough to not be fatiguing.

The trigger is called S.A.T. Smooth Action Trigger and that exactly describes it. Silky smooth to use. Not as good as a CFX with a GRT trigger – not as good as a Hatsan Quattro or a Weihrauch Record. Nevertheless it is very good and no thoughts of rushing out to buy a GRT. This trigger is nice to use and generates confidence. There is a long very light first pressure that is good for getting your sight picture and breathing sorted out and then a firm and long second pull, almost a creep. The second stage is adjustable for travel length only and the screw is wound all the way in. Maybe a slightly longer screw would shorten up the pull but I am not rushing out to get one.The trigger is a very safe one and probably influenced by European safety considerations. Of course the standard Gamo trigger blocking safety catch and anti bear trap.

The breach is the rotary BSA type and extraordinarily robust. I can say through years of use and abuse on a CFX. It is just as good and maybe better to use than the sliding breach on an underlever Weihrauch. You have to make sure the pellet is properly seated or the rotary action will crush the skirt.

The barrel I am told is a BSA hammer forged one. WARNING: before shooting clean the barrel. The bore is coated with some rusty coloured coating. At first I thought it was rust because it took solvent and lots of patches to get it clean. Looking down the barrel it looks true with no shadows or marks and good crisp lands. Then on to the muzzle.

The muzzle must be designed by a fashion designer to comply with the latest trend. To me it looks ungainly. The plastic muzzle break is a two part thing with movement between each part with no baffles to justify it. It is a push fit over a splined tit on the end of the barrel and held by a grub screw. The whole thing moves and vibrates on discharge. On top of that the spring loaded cocking lever catch is plastic and sloppy. Not good to have things wobbling about on the muzzle when shooting. The remedy is easy – take it off. I have substituted a plastic clip that holds the cocking lever firmly with no movement at all. The same as on my CFX. The barrel end is tidied up with a plastic cover turned out of Delrin The other advantage is that it shortens the length by about 60 mms. The crown looks neat and tidy and no plans to cut the barrel.
The open sights are the ubiquitous day glow things. The best you can do with them is take the black felt tipped pen to the glowy bits and then they become useable. The open sights gave some intermittent respectable groups in between bouts of dieseling. No smoke but I could smell it. After two or three hundred pellets that is disappearing. The rifle now carries a 3 -9 Nikko Sterling non AO.

This rifle is not powerful. About six foot pounds. Although the cocking effort is light it seems to me to be a bit more than it should be for that modest power. Six foot pounds seems to be a requirement for Germany or the Netherlands so maybe it was designed for their laws. Not a lot if any of these guns are seen in NZ gun shops. Maybe the low power doesn’t appeal to young men. It is certainly not enough for  the ordinary airgun hunter or long range. The recoil is light and sharp and no spring noise, rattle or buzz.
 
The manual is a really a safety pamphlet and gives little other useful information.

Davey told me that the power is restricted because of a very small ( 1 mm) transfer port in the rotary breach so increasing the power would be a simple matter for  P&N HSS. The other CF guns have no trouble putting out good power but I have no plans for that in the near future.
 
Accuracy is excellent. Five pellets groups through one hole at 12 metres indoors. It will do this with H & N FTT as long as the shooter points it at the right spot. Easy but the shooter can err.
For someone who has been outspokenly critical of Gamo in the past I have to reconsider because this rifle appeals to me. It is a very good gun that pleases me immensely.

Photo to follow as soon as I remember how to do it.

 

    
« Last Edit: July 28, 2016, 12:38:15 PM by Novagun »

Offline slyrod

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Re: Gamo G Challenger
« Reply #1 on: July 28, 2016, 02:21:48 PM »
Great choice of words Hugh.....an enjoyable & imformal read.

At 6-7ftlbs, these would make excellent rifles for testing the correct operation of our field target 'knock-downs'

The styling of the laser rastererd graphics on the beech stock could be detracting for some. Now who of the new WAG owner's will be prepared to 'bog' fill & overspray their stock a Ferrari yellow?
« Last Edit: July 28, 2016, 02:34:45 PM by slyrod »
Respect the man with just one gun....he probably knows how to use it!

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Offline Davey

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Re: Gamo G Challenger
« Reply #2 on: July 28, 2016, 03:01:07 PM »
I'll be modding my stock, so I'll be thinking about a respray of some kind. Dunno bout yellow though...
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Offline Pauly5

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Gamo G Challenger
« Reply #3 on: July 28, 2016, 08:18:22 PM »
Instead of drilling out the port, just get another and swap them to suit. They come out easy enough.
I think his words were humbly  chosen after being "sprung" by his wife.
Good write up though.

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Offline Davey

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Re: Gamo G Challenger
« Reply #4 on: July 28, 2016, 09:12:30 PM »
Problem is the cfx port is the 3.2?mm fac power port. I think we'll need around 2.5mm to get the 10-12ftlb tune.
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Offline Pauly5

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Re: Gamo G Challenger
« Reply #5 on: July 28, 2016, 10:00:56 PM »
Fair enough. Could the transfer port be threaded to accept a hollow grub screw? That way you could have different grub screws for different power. It would make it easier to tune by having a range of port sizes. Then if you could be bothered changing it, it would give you adaptability for 10 m targets and then for something like FT, SFT, GST and KFC.

Who will be brave enough to butcher their new gun? Mind you, quite reversible with a new breech.

Does the smaller port provide an air cushion reducing recoil? Will a bigger port create more recoil?
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Offline swampy

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Gamo G Challenger
« Reply #6 on: July 28, 2016, 10:48:06 PM »
I read in Airgun World that the only things that would change recoil would be changing the weight of the piston, weight of the gun or altering the the spring. Everything else just changes noise and vibration. Don't know if that is true or not from my limited experience.
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Offline Novagun

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Re: Gamo G Challenger
« Reply #7 on: July 31, 2016, 05:09:20 PM »
Had to try it. I changed the trigger adjustment screw for a slightly longer one and it is just how I want it.
No need to even think of a GRT.
The transfer port - one day but no just yet.

The revolving breach block lends itself to drilling and taping and then having changeable brass inserts of any size that you fancy. The one certain thing that Jim from Airgun World has established is that changing the transfer port size changes more than just the airflow. Piston cushioning and piston rebound are affected and thus recoil.

Offline Pauly5

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Gamo G Challenger
« Reply #8 on: July 31, 2016, 05:17:48 PM »
I hope your trigger is safe though. Don't want a pellet travelling up through the floor from the workshop into the lounge. You'd be in more trouble.

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Offline Novagun

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Re: Gamo G Challenger
« Reply #9 on: August 08, 2016, 06:15:11 PM »
Well it didn't last long. Neither the resolve to leave alone nor the Gamo Challenger.

It started to shot erratically and when I tested it on the radiata penetration test it had lost a lot of power so it had to be  the piston seal. I pulled the gun to pieces and sure enough a sliver off the skirt.

Today I went to town and bought a new rolling breach block with a standard CFX transfer port. I forgot to measure the size of the transfer port but about 3mms. I also bought a new Gamo piston seal but in  the end I did not use it. My never humble opinion is that seals for Gamo and Hatsan are too hard. It may be so for most cheap to mid priced guns.

The exercise was a chance to give the innards a good wash out and clean up.
I reshaped a 25 mm hydraulic seal to fit the piston and the compression tube bore and put it back together.
A few pellets to foul the bore a bit and accuracy is back to normal.
It is hard to judge but I think recoil is reduced because the gun is shooting very smoothly. I think the small bore of the original transfer port was causing excess piston bounce.
According to the radiata penetration test power has doubled.

 What next on another rainy day?

Offline Novagun

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Re: Gamo G Challenger
« Reply #10 on: August 08, 2016, 09:20:09 PM »
Well maybe not double the power but it has gone up. The radiata test is renown for its varying accuracy.
What is definite is the accuracy and the now very smooth shot cycle.

The next thing is to turn up a piston seal from urethane 90A because I have a little piece and see how that goes.
« Last Edit: August 08, 2016, 09:24:50 PM by Novagun »

Offline Pauly5

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Re: Gamo G Challenger
« Reply #11 on: August 08, 2016, 11:28:15 PM »
How is the accuracy? What sized groups are you getting, and is that with a scope or open sights?
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Offline Novagun

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Re: Gamo G Challenger
« Reply #12 on: August 09, 2016, 08:36:11 AM »
Five shot groups with a hole about 7 or 8 mms. Often single shots through an existing pellet hole. Shooting standing with rest at 12 metres and a scope. The open sights are pretty ordinary and not fine enough and I can't see the single pellet holes without a scope.

I have my share of poor shots but I am certain that is because of the wobbly shooter and not the rifle.
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Offline Davey

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Re: Gamo G Challenger
« Reply #13 on: September 01, 2016, 09:31:52 PM »


Here is a photo of Novagun's G Challenger and CFX.
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Offline Mintie

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Re: Gamo G Challenger
« Reply #14 on: September 26, 2016, 01:48:54 PM »
Had a look at one of these in hunting and fishing today, while it looks nice it is horrifically over priced at $750 imo, and after being ignored for 15 mins in the shop I was out.
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