2011 problems...

[dwalker]

Well one problem really. At the match this weekend my newly (less than 600 rounds at this point, under 200 at the beginning of the match) finished 2011 would occasionally not fire when the hammer dropped. PLEASE NOTE!!! Ammo being used was Remington UMC yelow box 115gr factory loads.

Ignition is
EGW Ultimate ignition kit
EGW titanium hammer strut
Ed Brown titanium firing pin
IIRC mainspring is the 19lb ISMI spring that comes with the EGW kit
Sear spring is EGW that came with thier kit.
Hammer spring is I believe a Wilson but could be Ed Brown.
Recoil spring is Wilson 8#, full length rod, no shok-buff or anything goofy.

NOTE: the EGW hammer/sear comes with thier "neutral" sear surface, and I have not done the final surface and polish, as I wanted to get a few rounds down it to expose any other issues before making it a super light trigger.

The specific mode of failure was pull trigger, no bang, rack slide, pull trigger, gun go bang. Gun will run fine, then randomly repeat failure.

Tore the gun back at the hotel, nothing obviously wrong. Checked firing pin safety timing, seemed fine. Firing pin is in perfect condition. Malfunction is intermittent and a serious PITA. No difference in trigger feel when there is a malfunction. I pull trigger, gun does not go bang. At least once I thumbed the hammer back, pulled trigger, still FTF. Gun did not fire until slide racked and round ejected. This happened at least 10 times over around 400 rounds from two different 250 round boxes of UMC 115gr.

Only working theories I have is the possibility that the slide is not coming completely forward on some shots due to being limp-wristed which lets the hammer fall but not actually hit the firing pin square. This seems unlikely because the hammer falling should push the slide completely into battery which would then fire when the hammer is thumbed back. Another option is the firing pin safety randomly engaging, which again seems unlikely, but??

I should also note the gun shoots super sweet otherwise, the Nowlin barrel is super accurate and it cycles nice and smooth.

[jericho89]

were you able to recover those rounds and make them fire?

[dwalker]

were you able to recover those rounds and make them fire?

No, unfortunately during the match I was not able to tell my ejected rounds from anyone elses so was not able to pick them up and even look at the primer or try to make them shoot. I was able to get the gun to malfunction once on the test range and that round fired found once cycled back through the gun. Pretty convinced it not an ammo issue, but TBH it might be hard primers have to be hit just right and when the gun is running fast the firing pin doesnt hit right. Problem with that thought is I did try thumbing the hammer back and shooting the un-ejected misfired round and it did not fire.

[cooper74]

Hows your alignment?... checking your spent cartridges, is the firing pin hitting center?

Also, I'm not following what you mean when you say firing pin safety... I keep picturing a series 80 system.. but 2011s don't have that... what am I missing?

Possibly the firing pin binding in the firing pin channel? Maybe slowing it just enough to cause light primer strikes.

[ThatFishGuy]

Likely a combination of things. If you have primers that are on the hard side, you're likely experiencing light primer strikes. You're using a titanium pin with a reduced power mainspring. That's a recipe for light strikes, especially if they're hitting off center. Springfield uses those firing pins, but paired with something like a 24lb mainspring.

[dwalker]

Hows your alignment?... checking your spent cartridges, is the firing pin hitting center?

Also, I'm not following what you mean when you say firing pin safety... I keep picturing a series 80 system.. but 2011s don't have that... what am I missing?

Possibly the firing pin binding in the firing pin channel? Maybe slowing it just enough to cause light primer strikes.

Sorry I should not post when I have been awake for more than 36 hours. I meant the grip safety, I checked the grip safety to make sure it was positively disengaging and not causing any sort of issue, which was one of those "I cant find anything wrong so maybe something weird is going on" sort of things.

[dwalker]

Likely a combination of things. If you have primers that are on the hard side, you're likely experiencing light primer strikes. You're using a titanium pin with a reduced power mainspring. That's a recipe for light strikes, especially if they're hitting off center. Springfield uses those firing pins, but paired with something like a 24lb mainspring.

Agreed the ignition combo is the likely issue, so am going to change out the mainspring and see if that changes anything. I am weirded out a bit by the fact that even after re cocking the hammer the gun did not go bang until I racked the slide.

Will check the cases next range trip again but my recollection is the primer strikes are centered. Not going to trust my memory on that though.

Probably also going to change out the plastic fantastic STI mainspring housing for a metal one. Its probably pointless, but meh, cheap to do and wont hurt anything.

[7 Sprig]

Check the bottom of the firing pin stop , the hammer could be hitting it not allowing it to fall fully with force.

I had this happen on 2 different guns causing the exact thing you are describing.

One i built the other was a new firing pin stop had been installed in a older gun.

Rounding the bottom , giving more it clearance corrected the issue in both cases. My build currently has 10k on it since the correction and no issues.

Am running a 17# mainspring so the 19# should be enough

[MosinVirus]

If the slide is all the way forward, the hammer should not strike the bottom of the FP stop. Rounding the FP stop on the bottom is usually done to reduce the resistance of the hammer when the slide is moving back and cocking the hammer in the process, because it moves the contact point between the two higher and away from the "hinge" - the hammer pin. People frequently get EGW square bottom FP stops to increase dwell time and reduce the speed of the slide coming back, but that is on .45 and 10mm.

On a 9mm you would want to have a very rounded or sloped FP Stop since 9mm factory ammo doesn't have thejuice to move a heavy slide with authority, hence the low power recoil spring.

Having said that, low power recoil springs can produce FTRB issues, and if the disconnector slot and disconnector are not timed correctly, the hammer will drop even if the slide is not fully in battery, and then the hammer will strike the FP stop incorrectly with little force delivered to the FP.

If the case here is that the slide doesn't return to battery, rounding the FP stop may not be the right fix.

I would approach it from a slide weight reduction / recoil spring weight increase perspective.

I am no authority on the matter though, but I did try very many things when trying to make my 9mm cycle properly with a heavy compensator and using factory 9mm 115 grain ammo.

One of the issues was the slide not returning to battery and hammer dropping with no bang.

[7 Sprig]

Mine was in battery and still had clearance issues . Am sure tolerances very , was just what i experienced.

[MosinVirus]

Mine was in battery and still had clearance issues . Am sure tolerances very , was just what i experienced.

Was it a production gun?

[7 Sprig]

No , i built from a limited 10 frame with a sti slide .

[dwalker]

If the slide is all the way forward, the hammer should not strike the bottom of the FP stop. Rounding the FP stop on the bottom is usually done to reduce the resistance of the hammer when the slide is moving back and cocking the hammer in the process, because it moves the contact point between the two higher and away from the "hinge" - the hammer pin. People frequently get EGW square bottom FP stops to increase dwell time and reduce the speed of the slide coming back, but that is on .45 and 10mm.

On a 9mm you would want to have a very rounded or sloped FP Stop since 9mm factory ammo doesn't have thejuice to move a heavy slide with authority, hence the low power recoil spring.

Having said that, low power recoil springs can produce FTRB issues, and if the disconnector slot and disconnector are not timed correctly, the hammer will drop even if the slide is not fully in battery, and then the hammer will strike the FP stop incorrectly with little force delivered to the FP.

If the case here is that the slide doesn't return to battery, rounding the FP stop may not be the right fix.

I would approach it from a slide weight reduction / recoil spring weight increase perspective.

I am no authority on the matter though, but I did try very many things when trying to make my 9mm cycle properly with a heavy compensator and using factory 9mm 115 grain ammo.

One of the issues was the slide not returning to battery and hammer dropping with no bang.

I think you have hit on it honestly. I think on the third or fourth fast shot in a string I may be limp wristing it slightly, which is enough to have a very slight FTRB in which the hammer will drop but no bang, and that would also explain why re-cocking the hammer produces no bang, although the hammer striking when dry fired to simulate this has returned the slide to battery with a cartridge in the chamber and the tension of a loaded mag it may not do so.
Racking the slide returns the slide back into full battery and bang goes the gun. I have a 10# recoil spring I may try, and I am considering sending the slide out for some lightening cuts as well.
Obviously I need to address the limp wristing or soft grip as well and really crush grip the gun. That alone may solve the issue.

[dwalker]

Mine was in battery and still had clearance issues . Am sure tolerances very , was just what i experienced.

My FP stop is rounded on the bottom and polished almost to a mirror shine to reduce the effort it takes to rack the slide. There may be something still to consider here, as the FP stop itself may be a little on the thick side and need to be thinned out some.

[dwalker]

Ok Correction- the recoil spring is a 10lb ISMI spring from Wilson. I may need to go to a 12lb'er but I dont have one here. All I have on hand is an 18lb spring , which is likely way too heavy.