Overtravel adjustment screw for Gamos with GTX trigger?

Overtravel adjustment screw for Gamos with GTX trigger?

Joined: April 15th, 2009, 2:16 am

June 13th, 2009, 10:48 pm #1

Quite possibly! So far, testing with my Big Cat has been very positive. If you have a Gamo with a GTX trigger installed and still have the original factory trigger adjustment screw and plastic block you may be on the way there, too. First thing to check is to make sure the plastic block does not interfere with the transfer bar or trigger. This is fairly easy as the block will probably fit a little loose in the trigger housing. Move the trigger and watch the block. If it does not move you are probably OK. Next thing is the screw. The original screw worked in my BC, but I replaced it with a socket head screw the same size, 3mm X 6mm. The extra thickness of the socket head allows more threads in the block. I also used a toothpick to put a small drop of rubbery craft glue in the hole in the block to help hold adjustment(poorman's Vibratite!). A good place to start adjustment is with the screw head about 1mm or so above the trigger housing. Make sure the screw does NOT extend out the other side of the block or it could interfere with the transfer bar and thereby change your trigger adjustment. Head for your favorite shooting lane to adjust. WARNING: These adjustments are made with the AG loaded to prevent dryfire and possible internal damage so please be careful!!! Cock and load (to prevent dryfire) your AG and test trigger. If it fires, turn the screw counterclockwise 1/4 turn at a time until it does not fire. Then make 1/8 or smaller turns clockwise until it fires again. If it doesn't fire to begin with, start with 1/8 or smaller turns clockwise until it does. EDIT: Please be extra careful during this process as the sear can be in a near fire position and the slightest thing could trip the sear causing the gun to fire. After further testing, once you reach this adjustment because of the fine threads on the screw I recommend giving the screw a 1/4 turn or more clockwise to help prevent a misfire and for safety. End of edit. Test for repeatability, I did have a couple of occasions where it slipped adjustment for some reason and wouldn't fire. Easy fix, just turn the screw clockwise a little. This mod works because the back of the GTX blade is solid. Unfortunately, I didn't have very good results with the factory trigger blade. I don't know if this mod will work with the Gamo clones as the BC is the only AG I have that uses the GTX. Perhaps some of you will test that for the rest of us and let us know what you find. This may or may not work in your Gamo, but so far it is working like a charm in my BC.
Good luck & safe shooting!!

"You've come far, pilgrim."------"Feels like far."
"Were it worth the trouble?"----"Ah, what trouble?"
Last edited by jmhenrichs on June 14th, 2009, 10:36 pm, edited 1 time in total.
Jim in SWMO

"You've come far, pilgrim."-------"Feels like far."
"Were it worth the trouble?"-----"Ah, what trouble?"
Reply
Share

Joined: April 15th, 2009, 2:16 am

June 14th, 2009, 4:44 pm #2

on this mod, read the conversation between Steve in NC and myself on the main. It may help to determine if it will work for your AG.

http://www.network54.com/Forum/79537/th ... X+trigger-

"You've come far, pilgrim."------"Feels like far."
"Were it worth the trouble?"----"Ah, what trouble?"
Jim in SWMO

"You've come far, pilgrim."-------"Feels like far."
"Were it worth the trouble?"-----"Ah, what trouble?"
Reply
Share

Joined: April 15th, 2009, 2:16 am

June 17th, 2009, 6:51 pm #3

Quite possibly! So far, testing with my Big Cat has been very positive. If you have a Gamo with a GTX trigger installed and still have the original factory trigger adjustment screw and plastic block you may be on the way there, too. First thing to check is to make sure the plastic block does not interfere with the transfer bar or trigger. This is fairly easy as the block will probably fit a little loose in the trigger housing. Move the trigger and watch the block. If it does not move you are probably OK. Next thing is the screw. The original screw worked in my BC, but I replaced it with a socket head screw the same size, 3mm X 6mm. The extra thickness of the socket head allows more threads in the block. I also used a toothpick to put a small drop of rubbery craft glue in the hole in the block to help hold adjustment(poorman's Vibratite!). A good place to start adjustment is with the screw head about 1mm or so above the trigger housing. Make sure the screw does NOT extend out the other side of the block or it could interfere with the transfer bar and thereby change your trigger adjustment. Head for your favorite shooting lane to adjust. WARNING: These adjustments are made with the AG loaded to prevent dryfire and possible internal damage so please be careful!!! Cock and load (to prevent dryfire) your AG and test trigger. If it fires, turn the screw counterclockwise 1/4 turn at a time until it does not fire. Then make 1/8 or smaller turns clockwise until it fires again. If it doesn't fire to begin with, start with 1/8 or smaller turns clockwise until it does. EDIT: Please be extra careful during this process as the sear can be in a near fire position and the slightest thing could trip the sear causing the gun to fire. After further testing, once you reach this adjustment because of the fine threads on the screw I recommend giving the screw a 1/4 turn or more clockwise to help prevent a misfire and for safety. End of edit. Test for repeatability, I did have a couple of occasions where it slipped adjustment for some reason and wouldn't fire. Easy fix, just turn the screw clockwise a little. This mod works because the back of the GTX blade is solid. Unfortunately, I didn't have very good results with the factory trigger blade. I don't know if this mod will work with the Gamo clones as the BC is the only AG I have that uses the GTX. Perhaps some of you will test that for the rest of us and let us know what you find. This may or may not work in your Gamo, but so far it is working like a charm in my BC.
Good luck & safe shooting!!

"You've come far, pilgrim."------"Feels like far."
"Were it worth the trouble?"----"Ah, what trouble?"
I now have around 250 shots with this mod and so far have only had the 2 occasions where the gun failed to fire. Both of those were in the first 15-20 shots and I'm sure they were because I was trying to get the adjustment too close to the firing stage. I am really liking this setup so far. Without the extra trigger overtravel my groups are slightly tighter.

After you reach the final adjustment, if you find that your trigger now has free play while the gun is uncocked most likely the screw has extended out the other side of the block and is interfering with the sear bar. Remove the screw and cut about 1mm off the end and try again. The idea is to have as much thread as possible in the block to keep the adjustment secure, but not extend out the other side. I mention the free play with the gun uncocked because I've noticed that when I cock my gun my GTX develops a tiny amount of free play. If I try to adjust this free play out I completely lose the second stage. There is so little free play that it's not even noticeable when shooting. This tiny bit of free play was there before the mod and has nothing to do with it. Hope this extra info helps.

EDIT: I feel I should be a little more specific about the free play my trigger has when the gun is cocked. I don't want anyone to lose any sleep over it. When I say "tiny amount", I mean about 1/32" of trigger free play. Certainly not enough to worry about and I haven't lost any sleep over it. In fact, I didn't even know it was there until I actually looked for it!

"You've come far, pilgrim."------"Feels like far."
"Were it worth the trouble?"----"Ah, what trouble?"
Last edited by jmhenrichs on June 18th, 2009, 4:45 pm, edited 1 time in total.
Jim in SWMO

"You've come far, pilgrim."-------"Feels like far."
"Were it worth the trouble?"-----"Ah, what trouble?"
Reply
Share

Joined: August 16th, 2008, 6:50 am

September 9th, 2009, 3:31 pm #4

Quite possibly! So far, testing with my Big Cat has been very positive. If you have a Gamo with a GTX trigger installed and still have the original factory trigger adjustment screw and plastic block you may be on the way there, too. First thing to check is to make sure the plastic block does not interfere with the transfer bar or trigger. This is fairly easy as the block will probably fit a little loose in the trigger housing. Move the trigger and watch the block. If it does not move you are probably OK. Next thing is the screw. The original screw worked in my BC, but I replaced it with a socket head screw the same size, 3mm X 6mm. The extra thickness of the socket head allows more threads in the block. I also used a toothpick to put a small drop of rubbery craft glue in the hole in the block to help hold adjustment(poorman's Vibratite!). A good place to start adjustment is with the screw head about 1mm or so above the trigger housing. Make sure the screw does NOT extend out the other side of the block or it could interfere with the transfer bar and thereby change your trigger adjustment. Head for your favorite shooting lane to adjust. WARNING: These adjustments are made with the AG loaded to prevent dryfire and possible internal damage so please be careful!!! Cock and load (to prevent dryfire) your AG and test trigger. If it fires, turn the screw counterclockwise 1/4 turn at a time until it does not fire. Then make 1/8 or smaller turns clockwise until it fires again. If it doesn't fire to begin with, start with 1/8 or smaller turns clockwise until it does. EDIT: Please be extra careful during this process as the sear can be in a near fire position and the slightest thing could trip the sear causing the gun to fire. After further testing, once you reach this adjustment because of the fine threads on the screw I recommend giving the screw a 1/4 turn or more clockwise to help prevent a misfire and for safety. End of edit. Test for repeatability, I did have a couple of occasions where it slipped adjustment for some reason and wouldn't fire. Easy fix, just turn the screw clockwise a little. This mod works because the back of the GTX blade is solid. Unfortunately, I didn't have very good results with the factory trigger blade. I don't know if this mod will work with the Gamo clones as the BC is the only AG I have that uses the GTX. Perhaps some of you will test that for the rest of us and let us know what you find. This may or may not work in your Gamo, but so far it is working like a charm in my BC.
Good luck & safe shooting!!

"You've come far, pilgrim."------"Feels like far."
"Were it worth the trouble?"----"Ah, what trouble?"
could this also apply to the Gamo 'stutzen'underlever model?

never squat down while wearing your spurs...will rogers
Reply
Share

Joined: April 15th, 2009, 2:16 am

September 9th, 2009, 10:37 pm #5

unit it might. But it will not work with the factory trigger blade as that trigger blade uses this screw for sear adjustment. It needs the GTX-G2 trigger with the solid blade, not the hollow rolled steel like the factory blade, to work as I have described. And it may vary from gun to gun as to whether or not it works. But it does work well in mine.

"You've come far, pilgrim."------"Feels like far."
"Were it worth the trouble?"----"Ah, what trouble?"
Jim in SWMO

"You've come far, pilgrim."-------"Feels like far."
"Were it worth the trouble?"-----"Ah, what trouble?"
Reply
Share

Joined: August 16th, 2008, 6:50 am

September 10th, 2009, 10:43 pm #6

i think i found my answer...

the gen II GTX trigger.

at least that's the advertisment on AOA. they also have installation and adjustments instructions i downloaded

i guess i'll find out...i sent for one. they show the Stutzen as one of the Gamos the trigger will fit.

never squat down while wearing your spurs...will rogers
Reply
Share

Joined: April 15th, 2009, 2:16 am

September 10th, 2009, 11:03 pm #7

I thought you were asking about my overtravel limiter mod. Yes, the GTX-G2 is a very nice trigger and adjusts into an excellent true two stage trigger. It's also very easy to install. I think you will like it.

"You've come far, pilgrim."------"Feels like far."
"Were it worth the trouble?"----"Ah, what trouble?"
Jim in SWMO

"You've come far, pilgrim."-------"Feels like far."
"Were it worth the trouble?"-----"Ah, what trouble?"
Reply
Share

Joined: August 16th, 2008, 6:50 am

September 12th, 2009, 5:08 pm #8

LOL...not to worry...i am very easily confused...

i should be getting the trigger in a day or so. i'm looking forward to the process.

never squat down while wearing your spurs...will rogers
Reply
Share