Anybody like puzzles?

[pries81]

I've been having a problem with a new sti 2011 six inch "doubling" or "bouncing" or whatever. And sometimes the hammer will follow to half-cock. I've had the gun to a very capable and talented gunsmith (many times) and we're both perplexed. It seems it will run for 300-400 rnds then double or bounce occasionally. I can't however replicate the problem by manipulating the trigger in practice or by slamming the slide forward (or by hitting it with a hammer). I lessened the reset pressure and this seemed to help. I got only one hammer follow (to half-cock) in two hundred rounds or so at a match.

[RePete]

Could it be the ammo?

Try some factory.

[Resjudicata]

I've been having a problem with a new sti 2011 six inch "doubling" or "bouncing" or whatever. And sometimes the hammer will follow to half-cock. I've had the gun to a very capable and talented gunsmith (many times) and we're both perplexed. It seems it will run for 300-400 rnds then double or bounce occasionally. I can't however replicate the problem by manipulating the trigger in practice or by slamming the slide forward (or by hitting it with a hammer). I lessened the reset pressure and this seemed to help. I got only one hammer follow (to half-cock) in two hundred rounds or so at a match.

What weight recoil spring are you using? How much lightening work has been done to the 6" slide?

When I first built my 6" top end I shot it with the full profile slide to see how it acted before taking weight off. Whether I had a 10# recoil spring in there or a 14# it would double quite often. For me the slide weight was moving the gun so much that I was resetting the trigger in recoil and then the gun was dipping enough that it would bump fire. All the testing I did would not replicate the problem in dry fire. It would only happen in live fire.

If you are not inadvertently bump firing then it is a problem with the trigger parts. The hammer/sear engagement, the interaction of the slide/disconnector/sear or the physical weight of the trigger shoe and trigger bow. I worked on a friend's trigger recently and it kept following after a trigger job. It turned out that the huge aluminum trigger shoe/bow he had in the gun was so heavy that when the gun closed hard the heavy trigger shoe would bounce back and trip the sear. We installed a lightweight Wilson trigger shoe/bow and the problem was solved.

Please list more information about the gun/parts and maybe post a pic of the gun so that folks know what parts are on the gun and it might help solve the problem.

Chris

[cheers623]

I've had this problem in the past with a few of my STI pistols. It turned out to be the overtravel screw in the trigger. It would move slightly after being fired a lot and eventually, while in a match, I would squeeze the trigger really hard during a string of fire and cause it to double or fall to half-cock. I could never get this to occur on the practice range and it would ALWAYS pass the traditional safety tests. You could drop the slide over and over, pin the trigger back, etc. etc. etc. and NEVER get it to happen. BUT, occasionally during a match, it would happen. Well, I finally called Dave Dawson and he explained that he had this happen on a lot of the pistols he'd sold and found that it was this overtravel screw.

What happens is that if the overtravel screw is adjusted so that it is has very little overtravel and then backs out during recoil slightly, when you are shooting during a match and squeeze the trigger a little harder than usual you can trap the sear enough to let it double or fall to half-cock. The solution is to adjust this screw and then loc-tite the little booger in place so that it won't back out. Once I did this I never had the problem again. FYI, this happened on 3 different pistols of mine STI and SV, and 1 of my wife's pistol (STI Trojan).

Hope that makes sense and helps.

cheers623

DVC

Edited June 23, 2010 by cheers623

[G-ManBart]

Put a different grip on it and see if that changes things. I've heard of a slightly bad grip causing similar problems. R,

[calishootr]

mine was droppingto half-cock alot more often than yours and i dropped in a new leaf spring that basically fixed things for me, for you??? it may vary, tappin it with a hammer didnt do the hammer or sear any good, bestto go back into it and see if the engagment surfaces are still at a true 90 degree's...

[Merlin Orr]

I've had this problem in the past with a few of my STI pistols. It turned out to be the overtravel screw in the trigger. It would move slightly after being fired a lot and eventually, while in a match, I would squeeze the trigger really hard during a string of fire and cause it to double or fall to half-cock. I could never get this to occur on the practice range and it would ALWAYS pass the traditional safety tests. You could drop the slide over and over, pin the trigger back, etc. etc. etc. and NEVER get it to happen. BUT, occasionally during a match, it would happen. Well, I finally called Dave Dawson and he explained that he had this happen on a lot of the pistols he'd sold and found that it was this overtravel screw.

What happens is that if the overtravel screw is adjusted so that it is has very little overtravel and then backs out during recoil slightly, when you are shooting during a match and squeeze the trigger a little harder than usual you can trap the sear enough to let it double or fall to half-cock. The solution is to adjust this screw and then loc-tite the little booger in place so that it won't back out. Once I did this I never had the problem again. FYI, this happened on 3 different pistols of mine STI and SV, and 1 of my wife's pistol (STI Trojan).

Hope that makes sense and helps.

cheers623

DVC

[want2race]

I too have struggled with a few 2011's and this same type of issue. For some, the hammer follow is from riding the trigger. If you're getting finger bounce, try increasing the rebound tension. What trigger are you using? The STI's are as light as you can find, I like those. What hammer are you running? I don't like Koenigs in 2011's. Lastly, what's your trigger pull weight?

[tpcdvc]

Not really enugh info on the gun, but some possibilities I can think of in the order of obvious to less are:

Not enough pressure on the sear from the sear spring.

Hammer/sear not mated properly

Not enough reset pressure from sear spring

Trigger over travel screw needs adjusting

Pin holes in frame not square

Bad pins

Hammer strut making contact with the sear spring (usually will leave a mark on the sear spring)

Disco not fit right (sometimes people take too much off the top and it will not quite clear the sear when the slide cycles)

[pries81]

I've been having a problem with a new sti 2011 six inch "doubling" or "bouncing" or whatever. And sometimes the hammer will follow to half-cock. I've had the gun to a very capable and talented gunsmith (many times) and we're both perplexed. It seems it will run for 300-400 rnds then double or bounce occasionally. I can't however replicate the problem by manipulating the trigger in practice or by slamming the slide forward (or by hitting it with a hammer). I lessened the reset pressure and this seemed to help. I got only one hammer follow (to half-cock) in two hundred rounds or so at a match.

What weight recoil spring are you using? How much lightening work has been done to the 6" slide?

When I first built my 6" top end I shot it with the full profile slide to see how it acted before taking weight off. Whether I had a 10# recoil spring in there or a 14# it would double quite often. For me the slide weight was moving the gun so much that I was resetting the trigger in recoil and then the gun was dipping enough that it would bump fire. All the testing I did would not replicate the problem in dry fire. It would only happen in live fire.

If you are not inadvertently bump firing then it is a problem with the trigger parts. The hammer/sear engagement, the interaction of the slide/disconnector/sear or the physical weight of the trigger shoe and trigger bow. I worked on a friend's trigger recently and it kept following after a trigger job. It turned out that the huge aluminum trigger shoe/bow he had in the gun was so heavy that when the gun closed hard the heavy trigger shoe would bounce back and trip the sear. We installed a lightweight Wilson trigger shoe/bow and the problem was solved.

Please list more information about the gun/parts and maybe post a pic of the gun so that folks know what parts are on the gun and it might help solve the problem.

Chris

I'm running a new 11# recoil spring. This problem seemed to happen about the time we put the lighter spring in. I bought the six inch unique slide, tri topped, cut some tunnel out, and put in some serrations. I love the way the gun shoots with the weight up front but I think you're on the right track with the slide lightening.

[pries81]

I've had this problem in the past with a few of my STI pistols. It turned out to be the overtravel screw in the trigger. It would move slightly after being fired a lot and eventually, while in a match, I would squeeze the trigger really hard during a string of fire and cause it to double or fall to half-cock. I could never get this to occur on the practice range and it would ALWAYS pass the traditional safety tests. You could drop the slide over and over, pin the trigger back, etc. etc. etc. and NEVER get it to happen. BUT, occasionally during a match, it would happen. Well, I finally called Dave Dawson and he explained that he had this happen on a lot of the pistols he'd sold and found that it was this overtravel screw.

What happens is that if the overtravel screw is adjusted so that it is has very little overtravel and then backs out during recoil slightly, when you are shooting during a match and squeeze the trigger a little harder than usual you can trap the sear enough to let it double or fall to half-cock. The solution is to adjust this screw and then loc-tite the little booger in place so that it won't back out. Once I did this I never had the problem again. FYI, this happened on 3 different pistols of mine STI and SV, and 1 of my wife's pistol (STI Trojan).

Hope that makes sense and helps.

cheers623

DVC

This seems like an easy fix...the thing is that this problem happens so intermitenly it's hard to pin down. I think this sounds like something good to try too.

[CSEMARTIN]

What are your split times when this is happening?

[sperman]

I've had this problem in the past with a few of my STI pistols. It turned out to be the overtravel screw in the trigger. It would move slightly after being fired a lot and eventually, while in a match, I would squeeze the trigger really hard during a string of fire and cause it to double or fall to half-cock. I could never get this to occur on the practice range and it would ALWAYS pass the traditional safety tests. You could drop the slide over and over, pin the trigger back, etc. etc. etc. and NEVER get it to happen. BUT, occasionally during a match, it would happen. Well, I finally called Dave Dawson and he explained that he had this happen on a lot of the pistols he'd sold and found that it was this overtravel screw.

What happens is that if the overtravel screw is adjusted so that it is has very little overtravel and then backs out during recoil slightly, when you are shooting during a match and squeeze the trigger a little harder than usual you can trap the sear enough to let it double or fall to half-cock. The solution is to adjust this screw and then loc-tite the little booger in place so that it won't back out. Once I did this I never had the problem again. FYI, this happened on 3 different pistols of mine STI and SV, and 1 of my wife's pistol (STI Trojan).

Hope that makes sense and helps.

cheers623

DVC

+1

[anachronism]

I'd try a little more sear spring tension first. I used to have this trouble with Videcki triggers & Clark leaf springs, with the split sear spring. I ended up using a Wilson (I believe) spring.

[pries81]

Not really enugh info on the gun, but some possibilities I can think of in the order of obvious to less are:

Not enough pressure on the sear from the sear spring.

Hammer/sear not mated properly

Not enough reset pressure from sear spring

Trigger over travel screw needs adjusting

Pin holes in frame not square

Bad pins

Hammer strut making contact with the sear spring (usually will leave a mark on the sear spring)

Disco not fit right (sometimes people take too much off the top and it will not quite clear the sear when the slide cycles)

Sorry for the late response...I was at area 1. I shot this gun by the way. I had one double and a couple hammer follows.

The gun has all STI trigger parts. The trigger pull is at 2.10 oz right now. Its a heavy trigger but we had to try something. After the match I put more tension on the disconnecter. I might also try to make the reset longer if that doesn't work. What about that?

Edited June 29, 2010 by pries81

[CSEMARTIN]

Put a lightweight trigger in the gun. The heavy trigger is probably the source of your problems.

[calishootr]

if it has STI parts in it, it probably has a skeleton trigger already in it, try this...with trigger pulled back to the rear, rotate the hammer thru its full range of motion, if you 'feel' a lil bump in there, you need to back out the trigger screw, that might help things

[pries81]

if it has STI parts in it, it probably has a skeleton trigger already in it, try this...with trigger pulled back to the rear, rotate the hammer thru its full range of motion, if you 'feel' a lil bump in there, you need to back out the trigger screw, that might help things

Thanks I'll try that

[tpcdvc]

Not really enugh info on the gun, but some possibilities I can think of in the order of obvious to less are:

Not enough pressure on the sear from the sear spring.

Hammer/sear not mated properly

Not enough reset pressure from sear spring

Trigger over travel screw needs adjusting

Pin holes in frame not square

Bad pins

Hammer strut making contact with the sear spring (usually will leave a mark on the sear spring)

Disco not fit right (sometimes people take too much off the top and it will not quite clear the sear when the slide cycles)

Sorry for the late response...I was at area 1. I shot this gun by the way. I had one double and a couple hammer follows.

The gun has all STI trigger parts. The trigger pull is at 2.10 oz right now. Its a heavy trigger but we had to try something. After the match I put more tension on the disconnecter. I might also try to make the reset longer if that doesn't work. What about that?

Go to Bob's website and go to magazine articles and read his trigger tuning article.

http://www.brazoscustom.com/Home.htm

It is possible that your overtravel screw has worked its way out and you have too much overtravel. I have seen this cause hammer follow. Follow Bob's instructions just to eliminate the trigger overtravel screw as the culpret. Plus if most our your weight is on the reset it could just need a better balance between the two leafs. I like about 12-14 oz on the reset but some like more. Bob talks about that in detail.

Also, check for a mark on your sear spring for the hammer strut macking contact. I had one do this and it caused hammer follow.

If they are all STI parts then I doubt that you have the disco problem unless your smith tweaked on it.?.?

[tpcdvc]

if it has STI parts in it, it probably has a skeleton trigger already in it, try this...with trigger pulled back to the rear, rotate the hammer thru its full range of motion, if you 'feel' a lil bump in there, you need to back out the trigger screw, that might help things

Thanks I'll try that

Make sure you adjust it per Bob's directions. You will not feel any bumps if it is adjusted too far the other way. But I have seen crazy things when the OT screw is too far out.

[Seth]

Bad grip. I went thru this with an Edge a couple of years ago. It went to Matt Mclearn then to STI and around the horn and back... finally STI swapped the grip and it suddenly ran perfectly.

Apparently there can be some deviation in the polymer grips to the point of causing this very problem.

[want2race]

I must have one of "those" grips too. LOL. Great posts on this topic btw.

[Seth]

I must have one of "those" grips too. LOL. Great posts on this topic btw.

Seems absurd, doesn't it? I couldn't believe the hands that touched that gun that couldn't prevent hammer follow... each smith that touched it failed until someone had the sense to swap the grip. Thousands of rounds later it was the right fix.

[G-ManBart]

Bad grip. I went thru this with an Edge a couple of years ago. It went to Matt Mclearn then to STI and around the horn and back... finally STI swapped the grip and it suddenly ran perfectly.

Apparently there can be some deviation in the polymer grips to the point of causing this very problem.

I've been waiting for you to chime in on this one!

[tpcdvc]

I must have one of "those" grips too. LOL. Great posts on this topic btw.

Seems absurd, doesn't it? I couldn't believe the hands that touched that gun that couldn't prevent hammer follow... each smith that touched it failed until someone had the sense to swap the grip. Thousands of rounds later it was the right fix.

That is just weird. I can't figure out how the grip could do this since the sear and hammer are pinned in the frame unless the grip is shifting during recoil or something. What was actually happening????

Was anything else replaced when the grip was replaced?

Edited July 1, 2010 by tpcdvc