Dave Dunn. Lon and other CFX'ers

Dave Dunn. Lon and other CFX'ers

Joined: December 15th, 2011, 9:40 pm

March 3rd, 2012, 5:28 pm #1

Recently obtained a new.old stock CFX in .177. Would like to make a few mods and this would be my most advanced effort and would like the advice of others before I start. In order of preference.1) Add a "gold" trigger. 2) I need to quite it down a bit, it is louder than my Benjamin Trail in .22 and that is about where I need to be at a minimum. I have a few fussy neighbors. Will a LDC be worth the effort? I've read some opinions for and against the LDC. 3)Will be doing a lube tune. I am not looking for more power as most of my shooting is paper punching. Would like to smooth the action out a bit. Again I've read for and against a nitro piston swap. Ant opinions? 4) Lastly, I thought I read a post about a mod to the loading port for easier access. Was I dreaming or is there such a mod. Any comments and help would be appreciated. Thanks in advance. Greg
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Joined: May 1st, 2009, 5:02 am

March 4th, 2012, 2:22 am #2

a .177 CFX and it doesn't seem that loud. I also own a Lightning XL with factory moderator, and I can tell a definite difference. A lot of the guys say a moderator doesn't make much difference, but I disagree. As for the gas ram, I have one that I'm going to try fitting to my CFX. I think it would be worth the effort. The CFX is very accurate and seems to be a high quality piece. It's well worth the effort, IMHO.
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Joined: August 20th, 2006, 5:36 am

March 4th, 2012, 5:17 pm #3

Recently obtained a new.old stock CFX in .177. Would like to make a few mods and this would be my most advanced effort and would like the advice of others before I start. In order of preference.1) Add a "gold" trigger. 2) I need to quite it down a bit, it is louder than my Benjamin Trail in .22 and that is about where I need to be at a minimum. I have a few fussy neighbors. Will a LDC be worth the effort? I've read some opinions for and against the LDC. 3)Will be doing a lube tune. I am not looking for more power as most of my shooting is paper punching. Would like to smooth the action out a bit. Again I've read for and against a nitro piston swap. Ant opinions? 4) Lastly, I thought I read a post about a mod to the loading port for easier access. Was I dreaming or is there such a mod. Any comments and help would be appreciated. Thanks in advance. Greg
Re: #1, do you HAVE to have a 2 stage trigger? I modded a stock trigger into a VERY nice single stage unit with the addition of a couple of nylon washers for a spacer and replacing the adjustment screw with a longer one. I think I like it better than the "gold" trigger, but then, I like a good single stage much more than a so-so or fake 2 stage.

I'm surprised yours is noisy, I always felt the CFX was one of the quieter springers out there. Of course, that's post-tune, before tuning they tend to be a typical Gamo . An LDC will make some difference in noise, but not nearly as much as a good tune, in my experience. But ANYTHING that gets rid of that ugly plastic monstrosity that Gamo sticks on the end of the barrel is a good thing!

The CFX is at it's best as a 12 fpe gun max IMO. I've gotten more out of them, but it takes more work than it's probably worth. The weakest link is the oring seal on the rotary breech, it's almost impossible to remove the rotary without damaging the seal, and only slightly less impossible to reassemble it without doing so. Be extremely meticulous about deburring. I've found that a much finer finish where the oring rides helps with longevity and sealing, I go to a near mirror polish in the last inch or so of the compression tube. You can get very fine wet/dry paper at any auto parts store, I went to 2K grit on my last one.

Don't know about the Nitro piston, I put a Theoben ram in mine. I think the higher piston velocity of the rams makes that troublesome rotary seal even more troublesome. For what you want it for, I don't think it would be worth the cost and hassle.

The only loading port mod I can think of really isn't a mod, it's a repair. Some of them over or under rotate on opening, getting the little pellet trough off center, making it more difficult to get the pellet to slide into the barrel. If it under rotates, you can simply trim the "bolt" a bit, if it over rotates, you can slip a small oring over it, maybe. They're finicky to load under the best of circumstances, especially if you have large fingers. But work with it a bit, and eventually you'll come up with a technique that works for you.

Hope that's some help, and feel free to email me direct if you need details on something. Later.

Dave
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Joined: October 21st, 2001, 3:36 am

March 4th, 2012, 5:44 pm #4

Recently obtained a new.old stock CFX in .177. Would like to make a few mods and this would be my most advanced effort and would like the advice of others before I start. In order of preference.1) Add a "gold" trigger. 2) I need to quite it down a bit, it is louder than my Benjamin Trail in .22 and that is about where I need to be at a minimum. I have a few fussy neighbors. Will a LDC be worth the effort? I've read some opinions for and against the LDC. 3)Will be doing a lube tune. I am not looking for more power as most of my shooting is paper punching. Would like to smooth the action out a bit. Again I've read for and against a nitro piston swap. Ant opinions? 4) Lastly, I thought I read a post about a mod to the loading port for easier access. Was I dreaming or is there such a mod. Any comments and help would be appreciated. Thanks in advance. Greg
I have no experience with sound suppresion on a springer. I've always been satisfied that most of the noise comes from the mechanics and pellet striking the target so I've never attempted discharge gas suppression. I just took it out and shot a few times and it's not loud and the noise seems to be mechanical noise.

No experience with gasram.

I have a soft tune w/stock spring and seal, a custom guide and 15 gram tophat from Rich in Mich.

Last edited by bigbore on March 4th, 2012, 5:47 pm, edited 1 time in total.
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Joined: December 15th, 2011, 9:40 pm

March 5th, 2012, 4:37 am #5

Recently obtained a new.old stock CFX in .177. Would like to make a few mods and this would be my most advanced effort and would like the advice of others before I start. In order of preference.1) Add a "gold" trigger. 2) I need to quite it down a bit, it is louder than my Benjamin Trail in .22 and that is about where I need to be at a minimum. I have a few fussy neighbors. Will a LDC be worth the effort? I've read some opinions for and against the LDC. 3)Will be doing a lube tune. I am not looking for more power as most of my shooting is paper punching. Would like to smooth the action out a bit. Again I've read for and against a nitro piston swap. Ant opinions? 4) Lastly, I thought I read a post about a mod to the loading port for easier access. Was I dreaming or is there such a mod. Any comments and help would be appreciated. Thanks in advance. Greg
Thanks guys. If you don't mind Griff I think I will contact you to see how your Ram conversion goes. I already installed the AoA trigger and I am working on getting the 2-stage adjustment dialed in. Sounds like I will do the Lube tune or ram conversion and then decide about the LDC. Thanks again.
Greg
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Joined: May 12th, 2010, 4:36 pm

March 11th, 2012, 5:01 pm #6

Re: #1, do you HAVE to have a 2 stage trigger? I modded a stock trigger into a VERY nice single stage unit with the addition of a couple of nylon washers for a spacer and replacing the adjustment screw with a longer one. I think I like it better than the "gold" trigger, but then, I like a good single stage much more than a so-so or fake 2 stage.

I'm surprised yours is noisy, I always felt the CFX was one of the quieter springers out there. Of course, that's post-tune, before tuning they tend to be a typical Gamo . An LDC will make some difference in noise, but not nearly as much as a good tune, in my experience. But ANYTHING that gets rid of that ugly plastic monstrosity that Gamo sticks on the end of the barrel is a good thing!

The CFX is at it's best as a 12 fpe gun max IMO. I've gotten more out of them, but it takes more work than it's probably worth. The weakest link is the oring seal on the rotary breech, it's almost impossible to remove the rotary without damaging the seal, and only slightly less impossible to reassemble it without doing so. Be extremely meticulous about deburring. I've found that a much finer finish where the oring rides helps with longevity and sealing, I go to a near mirror polish in the last inch or so of the compression tube. You can get very fine wet/dry paper at any auto parts store, I went to 2K grit on my last one.

Don't know about the Nitro piston, I put a Theoben ram in mine. I think the higher piston velocity of the rams makes that troublesome rotary seal even more troublesome. For what you want it for, I don't think it would be worth the cost and hassle.

The only loading port mod I can think of really isn't a mod, it's a repair. Some of them over or under rotate on opening, getting the little pellet trough off center, making it more difficult to get the pellet to slide into the barrel. If it under rotates, you can simply trim the "bolt" a bit, if it over rotates, you can slip a small oring over it, maybe. They're finicky to load under the best of circumstances, especially if you have large fingers. But work with it a bit, and eventually you'll come up with a technique that works for you.

Hope that's some help, and feel free to email me direct if you need details on something. Later.

Dave
Dave can you post enlarged pic of breech end of barrel and how to remove them? are they threaded to breech ?
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Joined: August 20th, 2006, 5:36 am

March 13th, 2012, 1:20 am #7

But I doubt I have any pics, I get too busy working on stuff to take any . But to answer your questions, yes, it's threaded into the compression tube, 13 X 1mm IIRC. There's a set screw to lock it, look in the bottom of one of the front stock screw holes. I still have the original barrel kicking around, I'll try to get a pic and get it posted sometime in the next day or so. I've gotten away from this rifle (again!), I've been concentrating on my HPA QB conversion, when I'm not working on restoring out old Airstream travel trailer. Later.

Dave
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Joined: October 10th, 2003, 5:24 am

April 17th, 2012, 11:36 pm #8

Recently obtained a new.old stock CFX in .177. Would like to make a few mods and this would be my most advanced effort and would like the advice of others before I start. In order of preference.1) Add a "gold" trigger. 2) I need to quite it down a bit, it is louder than my Benjamin Trail in .22 and that is about where I need to be at a minimum. I have a few fussy neighbors. Will a LDC be worth the effort? I've read some opinions for and against the LDC. 3)Will be doing a lube tune. I am not looking for more power as most of my shooting is paper punching. Would like to smooth the action out a bit. Again I've read for and against a nitro piston swap. Ant opinions? 4) Lastly, I thought I read a post about a mod to the loading port for easier access. Was I dreaming or is there such a mod. Any comments and help would be appreciated. Thanks in advance. Greg
Most of the noise is coming from the power plant at the other end of the barrel.

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mze
Joined: July 26th, 2009, 6:36 am

May 13th, 2012, 6:14 am #9

Recently obtained a new.old stock CFX in .177. Would like to make a few mods and this would be my most advanced effort and would like the advice of others before I start. In order of preference.1) Add a "gold" trigger. 2) I need to quite it down a bit, it is louder than my Benjamin Trail in .22 and that is about where I need to be at a minimum. I have a few fussy neighbors. Will a LDC be worth the effort? I've read some opinions for and against the LDC. 3)Will be doing a lube tune. I am not looking for more power as most of my shooting is paper punching. Would like to smooth the action out a bit. Again I've read for and against a nitro piston swap. Ant opinions? 4) Lastly, I thought I read a post about a mod to the loading port for easier access. Was I dreaming or is there such a mod. Any comments and help would be appreciated. Thanks in advance. Greg
Fitting one of the aluminium adjustable triggers is a must.

When a sound moderator is fitted to any air rifle, the internal noise will always be present.
I have fitted these items to many air rifles ranging in MV from 600fps to 1100 fps. The sound is almost inaudible at distances of 15m onwards.

I have 3 sizes of gas rams manufactured for me to suit most application.
Short for the smaller rifles like the smaller Gamos and BSA meteors.
Medium for the mid rage Gamos and Hatsans.
Long for the hairy 1250 magnums.
It is very important to get the ram pressures right.
For the mid range Gamos like the CFX, the pressure should be ±570-580 Newtons.

The Gamo IGT rifles have been an unmitigated disaster.
The ram installation is incorrect and the pressures are too high.
I have just completed rebuilding 600 new IGT Whispers, Shadows and Hunters for our local importer.
It was found that recoil was so high that scope rails and scopes were breaking off the rifles.

When I met with the Gamo Quality Assurance director and factory representative, I was able to have them shoot their IGT Whisper and My version for comparative purposes.
My version with a lower pressure gas ram, correctly installed, was quieter, had sweet recoil and shot faster by 40fps.

It is not commonly known that increasing ram pressure and steel spring strength reaches a point of diminishing returns.
Muzzle velocity increases with ram pressure increase or steel spring strength up to a point after which cocking simply becomes more difficult, recoil becomes unpleasant but muzzles velocity starts to decrease.
This decrease is caused by airflow through the transfer port being reduced by a venturi effect which effectively reduces the useful diameter of the port.
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Joined: December 13th, 2007, 1:01 am

June 12th, 2012, 1:46 am #10

Recently obtained a new.old stock CFX in .177. Would like to make a few mods and this would be my most advanced effort and would like the advice of others before I start. In order of preference.1) Add a "gold" trigger. 2) I need to quite it down a bit, it is louder than my Benjamin Trail in .22 and that is about where I need to be at a minimum. I have a few fussy neighbors. Will a LDC be worth the effort? I've read some opinions for and against the LDC. 3)Will be doing a lube tune. I am not looking for more power as most of my shooting is paper punching. Would like to smooth the action out a bit. Again I've read for and against a nitro piston swap. Ant opinions? 4) Lastly, I thought I read a post about a mod to the loading port for easier access. Was I dreaming or is there such a mod. Any comments and help would be appreciated. Thanks in advance. Greg
At least internally, involved filling the inside Of the stock with a spray in foam. Be careful, some foams will slightly melt the surface of the stock. Another alternative is stuffing it with a rubber type of packing foam. I also put a piece of electronic heat shrink over the spring guide.
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