On another forum, there's a thread in which the claim is made...

On another forum, there's a thread in which the claim is made...

Joined: May 12th, 2001, 1:29 pm

September 8th, 2006, 10:09 pm #1

...(by the "professional tuner" who worked on it) that a CFX that's making only 7.2fpe (i.e., low 600s with 8gr pellets) is "normal."

Can that be true? Any comment from CFX owners?

Steve
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Joined: February 4th, 2006, 8:11 pm

September 8th, 2006, 10:37 pm #2


1 The gun was a dud before.
That would explain the poor power output, but there are a few problems with that idea: Why would the tuner in question tune a gun that was so messed up. Also, if the problem could not be fixed by the tune, why would he/she charge full tune price for what is obviously a very messed up gun and should be returned or thrown away. The owner of the gun probably knew if something was wrong before sending it in b/c they knew it was only shooting 7fpe.

2 The gun was in better shape before the tune. In which case something was done incorrectly during the tune. So the tuner, in the final test, realized something was done incorrectly and should have opened it back up to see what was wrong. I'd guess this is the case b/c otherwise the owner wouldn't have thrown a big fit about the gun shooting like it did before.
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Joined: October 21st, 2001, 3:36 am

September 8th, 2006, 10:42 pm #3

...(by the "professional tuner" who worked on it) that a CFX that's making only 7.2fpe (i.e., low 600s with 8gr pellets) is "normal."

Can that be true? Any comment from CFX owners?

Steve
Using Crosman Quest parts and getting the "short" spring, then installing it without knowing it is for a 500 fps gun. Crosman sent me the Non-FAC manual with the "short" spring listed as the replacement part.

I ordered two, that is how I found out. I gave one away and returned the other.



Last edited by bigbore on September 8th, 2006, 10:43 pm, edited 1 time in total.
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Joined: May 12th, 2001, 1:29 pm

September 8th, 2006, 10:53 pm #4

...back to the customer in that condition - and then doing a song and dance about it being normal variation?

Here's (most of) the post in question:

"A couple of interesting things about the CFX and velocity and that is, not all CFX's are the same for sure. I believe the Gamo CFX is a very good gun but one of the things that seems to be unique about the CFX is there is a lot of variation in velocity from gun to gun as most of us know, especially in the .177's.

One of the main factors for this is it seems that the bore diameters do seem to be of a slightly larger diameter. (A loose fitting pellet in a bore can have a huge impact on velocity of course). This seems to be especially true of the newer CFX's but was apparent in some of the earlier ones also. I don't know why that is and has been a subject discussed at length on some of the other forums in the past.

I almost always use Gamo Hunters or Match pellets for pre-testing and post tune final testing. The reason being is that the Gamo Hunters or Match pellets seem to fit the chamber in most guns, and not just Gamo's, better than other pellets. That is not to say that it is the best pellet for the gun, it just seems to fit the chambers better. But in almost all of the CFX's, they seem to just about fall into the loading port as does just about any other pellet that I have tried. I'm sure that most of you that own CFX's are aware of that. Some pellets are so loose that they will just about fall through the bore.

Another thing that one needs to be aware of in the CFX is that after inserting a pellet into the loading port, it is very easy if the pellet is not completely inserted or the pellet skirt is distorted , to shear off tiny bits of the skirt as the port is being rotated and these particles can get between the rotating loading port cylinder and the barrel block and then gall the seal. This can also happen if there is loose lead particles on the pellet that can be transferred to the mechanism. If you are lucky, they may embed themselves into the seal and not cause a problem but that's not likely at least long term. Eventually they will cause seal damage. Also, many lubes can also damage the seal so be careful what you use in this area.

The thing that is disturbing about this is that it can possibly happen the very first time that you insert a pellet in a brand new gun or the hundredth time or possibly maybe never if you are lucky. When it does happen you will not even be aware of it until you start losing velocity.

One other very important thing to keep in mind. DO NOT ROTATE THE LOADING BLOCK UNLESS THE GUN IS COCKED. The pressure against the rotating block by the main spring can destroy or damage the seal in a heartbeat if rotated uncocked.

With all of that being said, when I finish up a CFX, I never know what to expect in velocity with any certainty."



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

September 8th, 2006, 11:12 pm #5

it sounds like it wasn't tested AFTER tuning.

Hmmmm...........where did that little spring go?

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Joined: February 4th, 2006, 8:11 pm

September 8th, 2006, 11:23 pm #6

go to gamo gate and read the string.
A post tune test was done according to the tuner.
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Joined: February 14th, 2006, 4:12 pm

September 9th, 2006, 12:05 am #7

...back to the customer in that condition - and then doing a song and dance about it being normal variation?

Here's (most of) the post in question:

"A couple of interesting things about the CFX and velocity and that is, not all CFX's are the same for sure. I believe the Gamo CFX is a very good gun but one of the things that seems to be unique about the CFX is there is a lot of variation in velocity from gun to gun as most of us know, especially in the .177's.

One of the main factors for this is it seems that the bore diameters do seem to be of a slightly larger diameter. (A loose fitting pellet in a bore can have a huge impact on velocity of course). This seems to be especially true of the newer CFX's but was apparent in some of the earlier ones also. I don't know why that is and has been a subject discussed at length on some of the other forums in the past.

I almost always use Gamo Hunters or Match pellets for pre-testing and post tune final testing. The reason being is that the Gamo Hunters or Match pellets seem to fit the chamber in most guns, and not just Gamo's, better than other pellets. That is not to say that it is the best pellet for the gun, it just seems to fit the chambers better. But in almost all of the CFX's, they seem to just about fall into the loading port as does just about any other pellet that I have tried. I'm sure that most of you that own CFX's are aware of that. Some pellets are so loose that they will just about fall through the bore.

Another thing that one needs to be aware of in the CFX is that after inserting a pellet into the loading port, it is very easy if the pellet is not completely inserted or the pellet skirt is distorted , to shear off tiny bits of the skirt as the port is being rotated and these particles can get between the rotating loading port cylinder and the barrel block and then gall the seal. This can also happen if there is loose lead particles on the pellet that can be transferred to the mechanism. If you are lucky, they may embed themselves into the seal and not cause a problem but that's not likely at least long term. Eventually they will cause seal damage. Also, many lubes can also damage the seal so be careful what you use in this area.

The thing that is disturbing about this is that it can possibly happen the very first time that you insert a pellet in a brand new gun or the hundredth time or possibly maybe never if you are lucky. When it does happen you will not even be aware of it until you start losing velocity.

One other very important thing to keep in mind. DO NOT ROTATE THE LOADING BLOCK UNLESS THE GUN IS COCKED. The pressure against the rotating block by the main spring can destroy or damage the seal in a heartbeat if rotated uncocked.

With all of that being said, when I finish up a CFX, I never know what to expect in velocity with any certainty."



Steve
exactly what I told Jock on the main many months ago about shearing off pellets with the load port. The CFX's I own (3) all do 14-17 FPE. The .22 gets 17FPE, the new one with large barrel gets 14.5 and the refurb w/ small barrel is 14FPE. Its super hard to get the loading port back in without tearing the rear O-ring, especially if you use the #30 that I now prefer. I can just about see 7FPE from a CFX thats missing that O-ring.
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Joined: October 21st, 2001, 3:36 am

September 9th, 2006, 12:08 am #8

go to gamo gate and read the string.
A post tune test was done according to the tuner.
That has to be a Euro gun, I would not have returned it to the owner without an email telling him about the anemic velocities. Springs are $6, seals are $3. You think he would have gone for it? By the tone of the post, I do.

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

September 9th, 2006, 12:10 am #9

exactly what I told Jock on the main many months ago about shearing off pellets with the load port. The CFX's I own (3) all do 14-17 FPE. The .22 gets 17FPE, the new one with large barrel gets 14.5 and the refurb w/ small barrel is 14FPE. Its super hard to get the loading port back in without tearing the rear O-ring, especially if you use the #30 that I now prefer. I can just about see 7FPE from a CFX thats missing that O-ring.
I drop in a JSB, and don't see it again until it's a hole in the paper.

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Joined: May 12th, 2001, 1:29 pm

September 9th, 2006, 12:16 am #10

That has to be a Euro gun, I would not have returned it to the owner without an email telling him about the anemic velocities. Springs are $6, seals are $3. You think he would have gone for it? By the tone of the post, I do.

...have a 7.5 Joule energy limit, but that's only 5.5fpe, much less than the CFX in question is making.

If I were to guess, I'd suspect that the gun is grossly defective (e.g., a broken mainspring) and was never even opened by the tuner.

Steve
Last edited by pneuguy on September 9th, 2006, 12:16 am, edited 1 time in total.
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