I got a Challenger (.177) with the cocking handle check balls missing and its reported to be a leaker for free. As best I can figure it was made around 2012 or so. I was going to try to mod the existing bolt assembly but I discovered that the factory bolt isn't up to much of a power increase. The air cylinder looks just like that on a Discovery so does anyone know if a Discovery receiver assembly would be a direct bolt on? How about Benjies Discovery replacement that's a repeater? Any ideas about how to up the power? Looks to have a finger adjustable hammer spring. Tighten that up, adjust the striker out and add a larger transfer port should do the job? Maybe a BStaley o ring mod to flatten the shot string. I would like to get the thing up to at least 12 foot pounds if possible. It has what looks like a Marauder trigger group. As far as fixing a leaky Benjie I have a Gen 1 Marauder which has provided me with an education on the subject. If I can get the power up I think it will make a nice close range pesting gun. Thanks for any help and advice on this project.
Adding Discovery breech assembly to a Crosman Challenger PCP target rifle?
- Thread starter Dan25
- Start date
Looks like I found a partial answer to the question of powering up question.
March 20, 2017 at 11:18 pm REPLY | QUOTE | FLAG | LINK
strikefast
Member
United States
Accuracy: +20
AJ, If you want to just go to 12 FPE, it is very simple.
Remove the barrel, take the transfer port out and put it in a vice with wood sides. Then drill it out to .080″ Put the barrel back on and you will be at 12 FPE!..However, if you intend to shoot WFTF class field target, you will need to install a Huma regulator. To install Just degasse the gun, unscrew the fill nipple cap and remove the air gauge. Then press the Huma in with a hollow tube or alum arrow so as to not change the setting. The setting should be 85 BAR, Without the reg. the rifle will go to around 13-14 FPE by the time it gets to the top of the bell curve. Too high for WFTF class. The Huma reg set at 85 BAR will keep it level at 12 FPE or a little less according to your adjustment of the pellet speed with the striker adjustment knob.
This is all I have done to my challenger and it gets 49 point of aim shots before it drops off the regulator. Best grouping is around 1500 PSI.
It is shooting 8.4 AA’s at 792 FPS for 11.70 FPE.
The Extreme spread is 8 and the standard deviation is 2….!
I did adjust the trigger pull to 7.6oz
It groups one hole with no wind at 30 yards. With no wind at 55 yards it will keep all under a dime.. The gun is amazingly accurate!
If you want to got to 18 FPE it is more complicated but doable. Hotrod62 has taken his up to 18 FPE so you can contact him for that info.
I had a disco and installed a LW Challanger barrel from Disco;s Are Us when Norm still had it. The barrel is shorter and you need to get the Challenger front sight piece to get it to equal the air tube,It will not allow a TKO to be installed If I remember right, I have an adapter that was made for the disco, that fits the barrel and is threaded 1/2′ UNF. The moderator won;t fit because of the shorter barrel.The air tube interferes… Either way, the disco was more accurate with the LW but no where near as accurate as the Challenger straight up…
Accuracy?? I made a field target stock for my Challenger, and it is the backup to my Steyr LG 110 FT…. But! it is every bit as accurate as the Steyr only at 12 FPE compared to the Steyrs nearly 20 FPE.. In fact at my practice session this morning I out shot my Styer with the Challenger. Guess I was more aware of the wind with the 12 FPE gun…!!??
Here are a pics of the gun as it is now with the new FT style stock I made for it from a curly maple blank…took the plastic knobs off and replaced them withh aluminum Paul
March 20, 2017 at 11:18 pm REPLY | QUOTE | FLAG | LINK
strikefastMember
United States
Accuracy: +20
AJ, If you want to just go to 12 FPE, it is very simple.
Remove the barrel, take the transfer port out and put it in a vice with wood sides. Then drill it out to .080″ Put the barrel back on and you will be at 12 FPE!..However, if you intend to shoot WFTF class field target, you will need to install a Huma regulator. To install Just degasse the gun, unscrew the fill nipple cap and remove the air gauge. Then press the Huma in with a hollow tube or alum arrow so as to not change the setting. The setting should be 85 BAR, Without the reg. the rifle will go to around 13-14 FPE by the time it gets to the top of the bell curve. Too high for WFTF class. The Huma reg set at 85 BAR will keep it level at 12 FPE or a little less according to your adjustment of the pellet speed with the striker adjustment knob.
This is all I have done to my challenger and it gets 49 point of aim shots before it drops off the regulator. Best grouping is around 1500 PSI.
It is shooting 8.4 AA’s at 792 FPS for 11.70 FPE.
The Extreme spread is 8 and the standard deviation is 2….!
I did adjust the trigger pull to 7.6oz
It groups one hole with no wind at 30 yards. With no wind at 55 yards it will keep all under a dime.. The gun is amazingly accurate!
If you want to got to 18 FPE it is more complicated but doable. Hotrod62 has taken his up to 18 FPE so you can contact him for that info.
I had a disco and installed a LW Challanger barrel from Disco;s Are Us when Norm still had it. The barrel is shorter and you need to get the Challenger front sight piece to get it to equal the air tube,It will not allow a TKO to be installed If I remember right, I have an adapter that was made for the disco, that fits the barrel and is threaded 1/2′ UNF. The moderator won;t fit because of the shorter barrel.The air tube interferes… Either way, the disco was more accurate with the LW but no where near as accurate as the Challenger straight up…
Accuracy?? I made a field target stock for my Challenger, and it is the backup to my Steyr LG 110 FT…. But! it is every bit as accurate as the Steyr only at 12 FPE compared to the Steyrs nearly 20 FPE.. In fact at my practice session this morning I out shot my Styer with the Challenger. Guess I was more aware of the wind with the 12 FPE gun…!!??
Here are a pics of the gun as it is now with the new FT style stock I made for it from a curly maple blank…took the plastic knobs off and replaced them withh aluminum Paul
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Looks like the disco breech will not work with the Challenger air tube. I think I would have to buy Disco air tube and receiver assembly. Going to see how many ft. lbs. the T handle will take before I explore the Disco receiver and air tube combo. Posting this to be an aid to others considering this mod.
Steel breech for Crosman Challenger? - Airguns & Guns Forum (gatewaytoairguns.org)
Steel breech for Crosman Challenger? - Airguns & Guns Forum (gatewaytoairguns.org)
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I increased my Challenger to 12 ftlb by enlarging the transfer port, and replacing the hammer spring with one from a Disco. I left the hammer adjustment screw alone.
It was then easy to achieve 12 ftlb by just adjusting the knurled hammer spring knob.
In the end, I decided to go with an Air Venturi Avenger, because I found it a PIA to single shot load the Challenger with a scope mounted. 10 shot magazines make the whole experience so much easier.
Eventually I detuned the Challenger back to about 600 fpm using wadcutters by just backing out the hammer spring adjustment knob leaving the enlarged transfer port and Discovery hammer spring installed.
By the way, you don't need to completely remove the barrel. Just loosen the barrel band, and the screw at the breech and extract the transfer port with a pair of tweezers or long nose pliers. Do pay attention to the orientation of the transfer port to get it in correctly when you reinstall it. It would also be a good idea to replace the transfer port seal with a new one, which can be purchased directly from Crosman.
If you retain the Challenger hammer spring, you will find yourself almost completely compressing the spring to obtain 12 ft. The discovery spring gives you a wide range of adjustment without compressing it.
It was then easy to achieve 12 ftlb by just adjusting the knurled hammer spring knob.
In the end, I decided to go with an Air Venturi Avenger, because I found it a PIA to single shot load the Challenger with a scope mounted. 10 shot magazines make the whole experience so much easier.
Eventually I detuned the Challenger back to about 600 fpm using wadcutters by just backing out the hammer spring adjustment knob leaving the enlarged transfer port and Discovery hammer spring installed.
By the way, you don't need to completely remove the barrel. Just loosen the barrel band, and the screw at the breech and extract the transfer port with a pair of tweezers or long nose pliers. Do pay attention to the orientation of the transfer port to get it in correctly when you reinstall it. It would also be a good idea to replace the transfer port seal with a new one, which can be purchased directly from Crosman.
If you retain the Challenger hammer spring, you will find yourself almost completely compressing the spring to obtain 12 ft. The discovery spring gives you a wide range of adjustment without compressing it.
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Thanks for taking your time to reply. I will drill out the transfer port and get a Disco spring. Since Im ordering from Crosman I will get a supply of seals for this one and my Marauder. Im going to try to push the power up as much as reasonably possible so I can give some light slugs and heavy pellets a try. Did you have any problems with the T-bolt blowing open with the higher power tune? I already have a way to add two springs connected to the bottom of the T handle and to the receiver should it become an issue. I would love to get to 16 ft. pounds if possible. This is just a fun project that fell into my lap that will be used for plinking and pesting. Agree about the single loading but I have a 25 cal Marauder, a 22 cal RWS 34 springer and need to go pick up a 22 cal used Hatsan 155 magnum springer. Thanks again.
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I never pushed the power much beyond 12 ftlb, but even then it took considerably more pull to open the bolt. The T-handle never came apart, but it was always in the back of my mind.
You can buy the balls which are 1/16 in locally at Ace hardware for almost nothing.
When ordering parts, I suggest reviewing the parts drawings and ordering an assortment of seals and fasteners along with a spare transfer port. The thin o-ring that supplies the drag inside of the T-handle is a special size only available from crosman. Get a few as you will probably need them. Using blue loctite is a must.
I assume you know about the extra spring in the trigger to allow you to lighten the trigger pull.
Good luck with your project.
You can buy the balls which are 1/16 in locally at Ace hardware for almost nothing.
When ordering parts, I suggest reviewing the parts drawings and ordering an assortment of seals and fasteners along with a spare transfer port. The thin o-ring that supplies the drag inside of the T-handle is a special size only available from crosman. Get a few as you will probably need them. Using blue loctite is a must.
I assume you know about the extra spring in the trigger to allow you to lighten the trigger pull.
Good luck with your project.
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No ACE hardware near me as I live in a small town in a rural area. I will give the one and only hardware store within sixty miles a try but have found the balls on Amazon six dollars for a hundred. Since I will be ordering from Crosman couldn't I just order a transfer port for a Discovery along with the striker spring and seals? I buy all my Marauder o rings from Industrial Rubber and Gasket in Alexandria when I travel there. What Crosman charges for simple o rings is criminal, five bucks for a ten cent ring. I will do your mods and maybe play with the valve striker on the hammer if it is adjustable like on the Marauder. I suspect this will end up just north of 12 ft. lbs. but we will see. I will post here should anyone else go down this road. Given the number of these rifles floating around ROTCs I expect some will follow with the new Challenger out now. I know this is going to kill my shot count but I have a buddy at the Fire Dept. and can get all the filtered 4500psi I need. That extra spring would be otherwise known as "the lawyer spring?" Thanks for you help.
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For others here is the owners manual with parts diagram for the Gen 2 Challenger
CH2009 Owner's Manual & EVP (2010-Present) – Crosman
CH2009 Owner's Manual & EVP (2010-Present) – Crosman
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Went to my local hardware store and they closed at six pm... Not even sure if they are open on Sunday. Life in rural deep south. The Crosman o ring you spoke of only available as a factory part is located at the rear of the bolt in the grove? The gun came with the T handle removed and steel balls missing. I checked the factory parts diagram and the o ring is listed as number six in the bolt assembly but it was left off the diagram. Im willing to bet industrial rubber and gasket in Alexandria LA will have it or one close enough. The ID of the T handle is 0.380 inches. The diameter of the grove in the bolt is 0.333 inches. Width of the grove is 0.060 inches. If I am successful I will post the o ring number for others.
Edit: Per the AS568 chart from The O Ring Store it looks like a # 011 with a ID of 5/16 inch (0.3125), thickness of 1/16 inch (0.070). Worth a try. BTW the o ring used in on the valve assembly, pressure port etc. for my Gen 1 Marauder is a #118, 70 durometer. Don't even try a 90 durometer as it is too hard and will not compress enough to work. Anybody have an idea what the o ring number is for the gauge block and valve is in the 2009 Challenger? I ass-u-me its the same as for the Discovery.
Edit: Per the AS568 chart from The O Ring Store it looks like a # 011 with a ID of 5/16 inch (0.3125), thickness of 1/16 inch (0.070). Worth a try. BTW the o ring used in on the valve assembly, pressure port etc. for my Gen 1 Marauder is a #118, 70 durometer. Don't even try a 90 durometer as it is too hard and will not compress enough to work. Anybody have an idea what the o ring number is for the gauge block and valve is in the 2009 Challenger? I ass-u-me its the same as for the Discovery.
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If I remember, the o-ring is not round, and has a rectangular cross section. It doesn't seal anything, but just adds enough drag to keep the handle or bolt from flopping around.
Yes it does fit in the groove, and is easy to cut it if you are not careful when disassembling. There is a very helpful YouTube video showing how to correctly service the assembly. do a Google Search for it.
When I was playing with mine, I had it apart so many times I felt I should equip the rifle with a zipper.
Yes it does fit in the groove, and is easy to cut it if you are not careful when disassembling. There is a very helpful YouTube video showing how to correctly service the assembly. do a Google Search for it.
When I was playing with mine, I had it apart so many times I felt I should equip the rifle with a zipper.
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d-cuttler Thanks for your reply. I thought it might be a standard O-ring. Wrong again. I will just order the factory part, a Discovery hammer spring, and a Prod transfer port as suggested by coldair in my 2018 thread. I first got into this project in Nov. 2018 but got sidelined with serious health issues and lost interest. I'm finishing old projects due to unfortunate events and is a welcome distraction. My plan for this rifle changes frequently, but for now I'm just going for a 12 pound setting with the T-handle until I can find a cheap used 17 cal. Disco. Have poured over parts diagrams and it looks like I need a lot of 17 cal. Discovery parts to push it to 18 or more foot pounds. The T-handle is a cluster F. I'm on the lookout for a used .177 Discovery to cannibalize the valve cap, tube, receiver group etc. and use the Challenger stock, trigger group and barrel to make a super accurate high powered frankin 17 cal rifle. Should be fun and I will have the only one. Cool beans as they say up north. PM me if you see one for sale in the Member Ads. I though of adding springs attached to the T-handle. I thought of adding multiple groves for the bolt o-ring but these are all half measures. Multiple groves is a no go as my machinist friend passed last month. Never take your time or time with friends for granted as there are no guarantees. Going to change out the valve retention screws to above grade 8 so I can up the fill pressure with the Disco conversion. At that point I can just copy what others have done to power tune the Discovery. The last question I have to answer is if the Challenger/Marauder trigger group will bolt up to the Discovery tube, pretty sure others have done this. If its just a matter of drilling and tapping a few holes that's not a problem. I'm going to call it the Challenger Hunter.
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Wow! That's becoming a complex project.
Order more than 1 of the bolt o-rings as they are easy to damage. I say that from experience.
My current project is breathing new life into a 116 year old Kodak folding camera that fell into my lap. It's almost ready for prime time.
Order more than 1 of the bolt o-rings as they are easy to damage. I say that from experience.
My current project is breathing new life into a 116 year old Kodak folding camera that fell into my lap. It's almost ready for prime time.
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d-cuttler I just edited my post, think your camera project is wild. Wouldn't mind seeing before and after pics if the Moderators will allow. After all this is an air gun channel. We parted out my parents house three years ago and I gave a 50's era German camera to a dear friend who wanted it. Even had the factory box and leather holster with sling.
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Made it to my hardware store and evidently they are using a different pattern of numbering O rings than the AS568 chart from The O ring store. Evidently there are numerous O ring charts. Got a couple of small O rings and both were two thick to allow the T-handle to to slide over them. Just for giggles Im going to slide the O rings over a wooden pencil and wear them down on my belt sander to see if I can get them to fit while I wait on Crosman parts.
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