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Discussion Starter #1
First of all...Let me say that I dearly hope I'm wrong about this. But after reading Setzer's torture test results the other day and comparing them to a similar problem with single action fire, that I recently had. I've taken a good hard look at the two piece sear on the FN FNP's...And I'm afraid there may be a design problem.

The Browning Pro's use a one piece sear. With a bar that fits into a slot on the sear actuator (Part #40 on the Browning Pro) lifting the sear and allowing the hammer to fall. The Browning sear has two holes on the bottom that the sear pin (Part #41 on the Browning Pro) fits though and tilts up on to release the hammer. This should work great, as the sear is evenly lifted in one piece and rises evenly allowing the hammer to break cleanly. One spring holds tension on the sear (Part #42 on the browning Pro.)

http://www.freespaces.com/laliqueinformation/Dump/pro940parts.pdf

The FN's on the other hand use a two piece sear arrangement



(Please forgive my camera)

The Sear Actuator has been elongated, with a notch, that a tab on the single action sear fits into. Lifting the single action sear to release the hammer in single action. Here lies the problem. It appears that the tolerance of the hole in the single action sear, that the single action sear rides the sear pin on the upswing of the release, is to wide and allows the single action sear to tilt as the sear actuator notch pushes the tab on the single action sear upward for the release.







I've posted three pics, of three different trigger pulls in single action. All of the picks were taken as the trigger was being pulled in single action and hopefully the pics are clear enough to show the tilt of the single action sear, just before hammer break. The Tilting of the sear can be visualized with the slide on as well.

The tilting single action sear causes the corner of the single action sear to retain the hammer and is the cause of the single action "pull all the way to and though the trigger stop" malfunction. It can cause a malfunction in the FNP9M (And possibly the other FNP's as well.), where one pulls the trigger all the way to the trigger stop and the pistol does not fire, unless about 20 pounds of pressure are exerted on the trigger.

I hate to be the one to bring this bit of bad news and encourage all FNP owners to examine their pistols, disassemble and look to see if this problem is as common as I suspect it is. Again I dearly hope I'm wrong about this. I've been looking at the problem for two weeks now and didn't want to post this, until I was absolutely certain that the problem was not an isolated incident, limited to my personal FNP9M.

This is in no way FN bashing, because I love FNH USA. I see it more as we the owners of FN products, acting as FN's pit crew and finding a small glitch, that is probably easily remedied to make the FNP a better pistol.

This problem could probably be solved with a .02 cent bushing for the single action sear or making the tit on the sear actuator that the trigger bar hits slightly longer.

There is no need to start an internet brushfire of criticism of the whole FNP design here. But this is a potentially serious FTF problem that we would be remiss in not bringing to FNH USA's attention.

Evo
 

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How are you getting yours to do that? Simply pulling the trigger won't make mine do it, no matter how slow. Is there a certain series of events, or certain situations that would cause this to happen?
 

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You say that this problem can't happen with the Browning Pro pistols. Can it happen with the SAO versions of the FNP or only the DA/SA versions of the FNP?

Thanks.
 

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Discussion Starter #4
I don't own a browning Pro...So I can't state with any certainty, but looking at the design of the one piece sear. I'd make a guess that it would certialy be harder for this to occur.

As far as I know...Nobody but the guys at FNH USA have seen the inside of an FNP SAO Fire Control Group yet. Though I'd be very surprised if the coming SAO FNP had a two piece sear group.

On a side note the FNP has two (Browning Pro Part #42) springs. one for the sear actuator and one for the sear itself.
 

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Discussion Starter #6
I admit we're in dangerous and uncharted waters here.

I've pulled the fire control group again and have pulled the sear pin, sear actuator and sear and am considering the problem further (Yes I know taking apart the fire control group probably voids my warranty, but its dead simple and I didn't just start taking apart guns yesterday.)

Just examining the sear on the sear pin. I observe a little slop in the tolerance of the hole in the Sear and the Sear Pin, that seems to account for the sears ability to tilt.

It almost appears that if I could find a paper thin washer that would go over the sear pin between the sear and the poly wall of the fire control group this problem might be solved.

I need to run down to Lowes and scratch my head a bit.

Evopsych...Taking one for the team.
 

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I still don't understand how you're actually getting yours to do this. Does this occur after a string of firing and it gets dirty, or what?
 

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Discussion Starter #8
Well Setzer...how do you suppose yours did it...Gunk in the action really isn't much of a technical explanation.

Something must have been going on in there to make your hammer not fall. 20 pounds against the trigger stop ain't the normal state of affairs...Something made that happen. Something caused your sear not to rise fully and release the hammer.

I'm endeavoring to figure out what that something is. If there's a single action reliability problem. I'd like to know about it and fix it now, on this board, rather than wait until somebody has to do a single action critical shot placement, in a life or death situation and have the trigger go all the way to the stop and the hammer not fall.
 

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Discussion Starter #10
Do you remember where the review was?
 

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I wish I'd bothered to wait to clean the pistol so that I could more closely examine why exactly it was doing what it was, I didn't really think about it. I could repeat the tests, but I'd really rather not. Do you think it would help crack this nut, I can make a quick trip to wally world and pick up some rounds if it'll help.
 

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Evopsych said:
As far as I know...Nobody but the guys at FNH USA have seen the inside of an FNP SAO Fire Control Group yet. Though I'd be very surprised if the coming SAO FNP had a two piece sear group.
Um, I own an FNP SAO...last time I checked, I didn't work for FNH USA. :wink:


 

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Discussion Starter #14
Thanks Galland. That was the Smoking Gun I was looking for, to confirm my diagnosis.

The relevant passage from the MadOgre article.

When I dry fired the gun, I found that the trigger was less than effective... to the point of being defective. Let me describe the defect for you... I would pull the trigger back in double action mode, pulling it all the way to the trigger stop and the gun would fire. As it should. However, in single action mode, and this is the most interesting part, the trigger would hit the frame as far back as it would go and then you had to squeeze further and harder – about 15 to 20 pounds worth – and then it would go off without any actual further trigger movement. Weird.

I was told by a fellow that knows FNP's better than I that the trigger was indeed defective. Of course it had to be. No gun company would put out a trigger like this on purpose... so I contacted FN and they arranged for the return of the pistol. I didn't hear anything back from them after that for a long number of weeks and I forgot about the pistol. I wrote two reviews since, and then all the sudden here is the very same pistol back with the same gouged up frame. I looked at it with suspicion and was hesitant to try it out. I didn't want to, but that is my job and that's what I do. I suffer so you don't have to. Your welcome.

FN repaired the gun and the trigger is about 500% better. Unfortunately it remains long and heavy and somehow awkward. Sure, it's relatively smooth. Much better than most factory guns, but not nearly as smooth as it should be. I know I have high expectations for handguns...
Golly gee whiz....Same problem.

After removing my Fire Control Group and pulling my Sear pin and removing the Sear, Sear Actuator and Springs. The problem was readily apparent. The Sear and Sear Actuator appear to be castings and either FNH USA got a batch of non spec Sears from the casting shop, or the metallurgy of the castings does not stand up to dry firing very well. (And there hasn't been THAT MUCH dry firing. I've owned this Pistol 3 months.) The Sear wobbled on the Sear pin with quite a bit of slop.

When the Sear actuator slot engages the Sear Tab, putting upward pressure in the interior side of the, either worn, or out of spec Sear...It causes... You guessed it...Sear Tilt. The exterior side of the Sear does not rise far enough to release the Hammer as the Hammer is retained by the lower exterior edge of the Sear.

It almost appears that the Two Piece Sear and Actuator were designed as an after thought, for the US Law Enforcement Market. and the mechanical relationship of the Sear and Actuator were not to well thought out.

Another bit of speculation on my part. Would be that every time the Sear actuator lifts the interior side of the sear. It puts a downward pressure on the upper inside surface of the Sear Pin Hole on the exterior side of the sear, causing belling wear, from approximately 10 o'clock to 3 o'clock on the exterior side of the Sear Pin hole and from approximately 8 o'clock to 3 o'clock on the interior side of the Sear Pin Hole. As the soft metal of the casting bells on both sides of the Sear Pin Hole, it allows the sear to tilt more and more over time. the Polymer sides of the Fire Control Group allowing enough flex, to allow the Sear to Tilt.

Again pure speculation on my part. The Sear Pin Hole may have been out of spec since I got the pistol.

Again. I am not an FN basher. Nor Am I one of those Glocks, Sig or HK Rules guys, that find a reason to bash every new pistol that comes on the market.

The guys that run this site know, that there are few poster here or on the Arfcom Pistol Forums, that have been a bigger proponent of the FNP.

The reason I'm pursuing this problem, is because I believe we may have stumbled onto a serious and potentially deadly design flaw That FNH USA needs to be made aware of. As it effects the safety of those who carry the FNP as a serious defensive weapon.

I want the FNP to be a success, but I believe there's a serious problem with the DA Fire Control Mechanism.

If you have experienced a Single Action FTF in one of the DA FNP's, such as the FTF events described here. Please post a description of the event and please give an estimate of rounds fired and dry firing practice frequency. As I am compiling data on this problem.

Thanks

Evo
 

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Discussion Starter #16
Believe me Ship...Nobody here hopes this is a couple of isolated incidents of lemon DA Fire control assemblies more than me.

I've been agonizing about posting this for a week and a half. Ever since I first noted the problem (Long before I first pulled my DA Fire Control Group to attempt to better understand what was making the Sear Tilt.)

I keep hoping that somebody will come along and call me a bone head and explain how this is a simple problem easily remedied. Because I'd rather endure internet ridicule for a couple of weeks, than be the guy that found a huge inherent design flaw and initiated a FN FS2000 Firing Pin style mass recall.

Thats why I want to gather data from other users and be absolutely certain about this, before calling FN.
 

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You said yours did it out of the box like the review that was posted earlier? Mine never did such a thing, it was only once the mechanism was gummed with nasties. I don't even know if the sear tilted or not, but I might just test it again to find out, that way we all have as much info as possible.
 

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Discussion Starter #18
Mine didn't seem to do it right out of the box.

Your malfunction could well be due to the fact that with the hammer back the Fire Control Assembly is exposed to gunk...

Gunk piled up on top of the sear could conceivably cause the problem you describe also Setz.
 

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I would think that this pistol would have been very heavily tested. I would also imagine that they know exactly what causes this problem by now.
Getting the info from them might be the hard part. If you contact them they will say send it in for repair. You would get it back fixed but I bet they would be tight lipped about exactly what was wrong. -Mike
 

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Discussion Starter #20
Can't contact FN about Getting it fixed over the weekend anyway.

I couldn't be lucky enough to talk them into just dropping a SAO Fire Control group in the thing and calling it good. That would be to much to hope for.

I'm a little disillusioned about the mechanics of the DA version at this point.
 
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