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Glock 17 FTF Issue


nhglyn
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I have a Gen 5 Glock 17 that I am reloading for on a Dillon 550 (reloading experience 20+ years).  Right now it has a 13# recoil spring in it (17# factory too hard for grandson to pull back).  Load right now is 3.8 grs Titegroup with Zero 115 gr. jacketed roundnose bullet.  OAL is 1.070 and they chrono at 1002.60 average.  But, every now and then I get a FTF as in attached photo.  So, what causes this?  Too short OAL?  Recoil spring weight?  Powder charge?  Suggestions appreciated.

Glock.jpg

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Not trying to be critical of the photography, but it's just off-angle enough for me to not be able to say authoritatively, but...

 

It appears that the slide is not coming back far enough to actually get BEHIND the case head to push it into the chamber.  If it doesn't, the stripper rail can actually "friction" the round out from under the magazine lips and start it towards the chamber.  Once the nose of the bullet hits the feedramp, all heck breaks loose and the base of the cartridge pushes down to go under the stripper rail.  In the military, that's called a "Bolt Over-ride". 

 

That is often caused by too much Recoil Spring, not enough power in the ammo, or not enough resistance to recoil being offered by the shooter (the infamous "limp wrist" malfunction).

 

13# sounds right for IPSC Minor loads, but your Ammo seems on the low side (actually sub-Minor at a 116 Power Factor).  Hodgdon recommends weights in the mid-4 grain range with jacketed 115s and TiteGroup.  Combine soft ammo with a 70 pound grandson and we have a perfect formula for this to occur, especially if his recoil-control skills are not perfect ("leaning back" stance, etc.)

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7 minutes ago, Braxton1 said:

Not trying to be critical of the photography, but it's just off-angle enough for me to not be able to say authoritatively, but...

 

It appears that the slide is not coming back far enough to actually get BEHIND the case head to push it into the chamber.  If it doesn't, the stripper rail can actually "friction" the round out from under the magazine lips and start it towards the chamber.  Once the nose of the bullet hits the feedramp, all heck breaks loose and the base of the cartridge pushes down to go under the stripper rail.  In the military, that's called a "Bolt Over-ride". 

 

That is often caused by too much Recoil Spring, not enough power in the ammo, or not enough resistance to recoil being offered by the shooter (the infamous "limp wrist" malfunction).

 

13# sounds right for IPSC Minor loads, but your Ammo seems on the low side (actually sub-Minor at a 116 Power Factor).  Hodgdon recommends weights in the mid-4 grain range with jacketed 115s and TiteGroup.  Combine soft ammo with a 70 pound grandson and we have a perfect formula for this to occur, especially if his recoil-control skills are not perfect ("leaning back" stance, etc.)

Thanks!  Will make adjustment and go to range tomorrow.  

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Hello: when my son was 8 we had some issues with a Glock 34 that would not cycle sub minor loads. I ended up with 136PF loads with 115's for him. I used a 13lb ISMI recoil spring in a Gen 3. On the Gen 5 G17 try a 11lb ISMI recoil spring and see how that goes. Use a lighter striker spring as well. My load was 4.1gr Tite Group, 115 plated bullets, 1.140" OAL and Federal primers. The kids can handle the recoil just fine if they grip it and rip it. Thanks, Eric

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2 hours ago, Aircooled6racer said:

Hello: when my son was 8 we had some issues with a Glock 34 that would not cycle sub minor loads. I ended up with 136PF loads with 115's for him. I used a 13lb ISMI recoil spring in a Gen 3. On the Gen 5 G17 try a 11lb ISMI recoil spring and see how that goes. Use a lighter striker spring as well. My load was 4.1gr Tite Group, 115 plated bullets, 1.140" OAL and Federal primers. The kids can handle the recoil just fine if they grip it and rip it. Thanks, Eric

My concern is, with an 11# spring, are you risking damage due to increased speed of slide?

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I’ve run thousands of rounds with oal’s from 1.060 to 1.145 on a 13lb recoil spring with a 4lb striker springs in my glocks.  So your oal should be fine.  Your power factor is only about 115. I would increase this to at least 135 and take it from there. Being that it’s a jacketed RN I would increase oal to about 1.125 to 1.135 and bump up load to make at least 135pf. There are loads of Titegroup recipes that should get you there. You need about 1150fps for a 132pf.

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Hello: You are shooting 115PF loads so the 11lb recoil spring will be fine. Winchester white box I chronoed years ago was 147PF out of a Glock 17 gen2. I shot a Glock 17 Gen 5 the other day with a 11lb recoil spring with 135Pf loads and it shot great, very flat shooting. Thanks, Eric

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Eric is very correct above.  IF you decide to go lighter on the Recoil Spring, please ensure that you use a Reduced Power Firing Pin Spring also.  There is a fine balancing act in the relationship between those to springs, as they work in opposite directions on the same plane.  If you don't change the FP Spring, then slide can be pulled out-of-battery during the trigger press or the slide's closing could be retarded to the point where the slide won't close.  Somewhere between 13# and 11 is where that really can start to show itself.

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15 hours ago, Braxton1 said:

That is often caused by too much Recoil Spring, not enough power in the ammo, or not enough resistance to recoil being offered by the shooter (the infamous "limp wrist" malfunction).

this is your answer 

you will need to "fix " one of these.    The 11 pound spring referred to above is a good option. You could possibly get by with a 12. A slight increases in powder to 4.0 would also help. Note for you information I run a 11 pound ISM spring in 3 different Glocks . 4.5 pound striker spring. Over 40k on each no wear issues.

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41 minutes ago, Braxton1 said:

Eric is very correct above.  IF you decide to go lighter on the Recoil Spring, please ensure that you use a Reduced Power Firing Pin Spring also.  There is a fine balancing act in the relationship between those to springs, as they work in opposite directions on the same plane.  If you don't change the FP Spring, then slide can be pulled out-of-battery during the trigger press or the slide's closing could be retarded to the point where the slide won't close.  Somewhere between 13# and 11 is where that really can start to show itself.

I should have mentioned that I have installed a Charlie Vanek trigger kit in it and installed the 4# firing pin spring, so I got that part covered.  Doing some testing today and, if need be, will order the 11# recoil spring.  Appreciate all the great answers.   Thanks.

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22 hours ago, Braxton1 said:

13# sounds right for IPSC Minor loads, but your Ammo seems on the low side (actually sub-Minor at a 116 Power Factor).  Hodgdon recommends weights in the mid-4 grain range with jacketed 115s and TiteGroup.  Combine soft ammo with a 70 pound grandson and we have a perfect formula for this to occur, especially if his recoil-control skills are not perfect ("leaning back" stance, etc.)

I didn't realize it was a 115 gr bullet. It's almost certainly too much recoil spring with that load. 

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2 hours ago, Jsjac said:

Does this only happen when your grandson shoots the gun ?

 Or does it happen to you also?

It has happened to me too, and I shot USPSA for 20+ years so I know it's not limp wristing.  I have bumped the fps up and am awaiting an 11# spring.  Should solve the problem.  Thanks.

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  • 3 weeks later...

Was shooting a Gen 3 G35 first as limited and later as an open gun with Carver Custom frame mounted DPP, threaded Double Diamond barrel with two slot compensator, tungsten guide rod with uncaptured factory recoil spring (17#) and a brass back strap secured magwell. Used local range reloads for several years without a problem. No data on the reloads. Shot the gun competitively for a good three years without a problem including almost two years with the reloads. I do not reload. 

 

Last year began having a similar problem with failures to feed, 2, 3 or 4 times a 250 round match. Set the gun aside after changing to lower recoil springs did not solve the problem. Photo included.

 

Have decided the range reloads that served me well for years need to be replaced since they are unknown factor/quality and I don’t have access to a chronograph. I was seduced by the price and nickel plated LAPD range brass.

 

I have the following factory ammunition in storage:

 

Armscor 180 gr, 953 FPS with predicted PF 171.5

American Eagle 165 gr, 1130 FPS with predicted PF 186

Federal Range 180 gr, 985 FPS with predicted PF 177

Federal Syntech 180 gr, 1010 FPS with predicted PF 182

 

What recoil spring should I start with, what should I look for other than the absence of the malfunction?

 

2B98BF9E-E859-4CDD-8C59-480278392386.jpeg

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I wish I could see this malfunction in-person.  It looks like the slide simply stopped right as the bullet nose made contact with the feed ramp and started upwards towards the chamber mouth.  That is an uncommon place for it to just "stop" like that.

 

Is there any chance that the Recoil Spring is simply worn-out?  Major .40's can be pretty brutal on springs.

 

If that's not the case, I might start looking at the magazine.  A few years ago, right after the Gen3 guns came to market, there was a factory change from a 10-coil Magazine Spring to an 11-coil.  This was done because the reliability of the gun suffered whenever running a light on the rail.  At my department, we found that the 11-coil springs were so tight, some female and smaller-statured shooters couldn't rack the slides.  Sometimes they'd even have a short-stroke malfunction in live-fire.  The mag wouldn't allow the stack to move downward to accommodate the stripper rail coming back.  We had to have them download the mags by one round.

 

I say all that to say this:  If the comp is bleeding off enough slide energy, the slide may be wanting to short-stroke on its own.  Add in a tightly-packed magazine and maybe a worn Recoil Spring, you could set up this malfunction pretty easily.

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On 12/14/2020 at 12:33 PM, Paul49 said:

Was shooting a Gen 3 G35 first as limited and later as an open gun with Carver Custom frame mounted DPP, threaded Double Diamond barrel with two slot compensator, tungsten guide rod with uncaptured factory recoil spring (17#) and a brass back strap secured magwell. Used local range reloads for several years without a problem. No data on the reloads. Shot the gun competitively for a good three years without a problem including almost two years with the reloads. I do not reload. 

 

Last year began having a similar problem with failures to feed, 2, 3 or 4 times a 250 round match. Set the gun aside after changing to lower recoil springs did not solve the problem. Photo included.

 

Have decided the range reloads that served me well for years need to be replaced since they are unknown factor/quality and I don’t have access to a chronograph. I was seduced by the price and nickel plated LAPD range brass.

 

I have the following factory ammunition in storage:

 

Armscor 180 gr, 953 FPS with predicted PF 171.5

American Eagle 165 gr, 1130 FPS with predicted PF 186

Federal Range 180 gr, 985 FPS with predicted PF 177

Federal Syntech 180 gr, 1010 FPS with predicted PF 182

 

What recoil spring should I start with, what should I look for other than the absence of the malfunction?

 

2B98BF9E-E859-4CDD-8C59-480278392386.jpeg

Your recoil spring should be tuned so that the empties are ejected 4-5 feet from the gun.  Too much recoil spring and the pistol won't function correctly.  Too light and you won't pick up cartridges from magazine properly, perhaps stovepipes, and can cause excessive battering on the slide/frame interface.  Keep several different weights of springs on hand and adjust as needed.  Also, springs can wear out... if a pistol is working, and then slowly begins to develop malfunctions, try replacing the spring with a new one of the same weight.

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On 11/23/2020 at 11:16 AM, nhglyn said:

I have a Gen 5 Glock 17 that I am reloading for on a Dillon 550 (reloading experience 20+ years).  Right now it has a 13# recoil spring in it (17# factory too hard for grandson to pull back).  Load right now is 3.8 grs Titegroup with Zero 115 gr. jacketed roundnose bullet.  OAL is 1.070 and they chrono at 1002.60 average.  But, every now and then I get a FTF as in attached photo.  So, what causes this?  Too short OAL?  Recoil spring weight?  Powder charge?  Suggestions appreciated.

Glock.jpg

My suggestion is that the cartridge OAL is too short.  Also, try 147 grain bullets at 130+ PF... there's a reason why that load is popular.  Light recoil.. and they function well.  I think you'll find it much better suited to the reduced recoil you're looking for than the 115 bullets.  I load blue bullets for 9mm minor in USPSA.  3.2 grains of Sport Pistol.. perfect functioning in my pistol.  I have both a G17 and a G34 and this load works perfectly with the appropriate recoil spring, which will be either 11# or 13#.  Look for ejection to be about 4-5 feet out of the pistol.

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Our Gen 5 Glock 34's will barely close the slide with a 11# recoil spring.  I think 13# is the minimum for the gen 5 34 but I am not sure about the 17.  Our Gen 3 34's run good with 11# springs but I do use 13# springs in those guns as well.  My match loads (N320 3.5 gr, PD 147 COL 1.145) are too soft for the Gen 5 guns to function with the factory recoil spring.

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On 12/15/2020 at 9:23 AM, Braxton1 said:

I wish I could see this malfunction in-person.  It looks like the slide simply stopped right as the bullet nose made contact with the feed ramp and started upwards towards the chamber mouth.  That is an uncommon place for it to just "stop" like that.

 

Is there any chance that the Recoil Spring is simply worn-out?  Major .40's can be pretty brutal on springs.

 

If that's not the case, I might start looking at the magazine.  A few years ago, right after the Gen3 guns came to market, there was a factory change from a 10-coil Magazine Spring to an 11-coil.  This was done because the reliability of the gun suffered whenever running a light on the rail.  At my department, we found that the 11-coil springs were so tight, some female and smaller-statured shooters couldn't rack the slides.  Sometimes they'd even have a short-stroke malfunction in live-fire.  The mag wouldn't allow the stack to move downward to accommodate the stripper rail coming back.  We had to have them download the mags by one round.

 

I say all that to say this:  If the comp is bleeding off enough slide energy, the slide may be wanting to short-stroke on its own.  Add in a tightly-packed magazine and maybe a worn Recoil Spring, you could set up this malfunction pretty easily.

 

The cartridge is actually cocked slightly sideways, to the left. The nose is hung up on the left edge of the chamber mouth.

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