FN Herstal Firearms banner

1 - 17 of 17 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
Hi guys,
I took my 17 out to the range for it's second outing. I had shot up about 3 boxes of Federal Fusion 150 grainers to start breaking the gun in and to have some brass to reload. I have since installed a Geissele trigger group as well as a Stryker angled bolt handle. The problem.....

I loaded up some more Fusion rounds (I purchased a case) and went to work on a 120 yard gong. The first and second shot fired normally (new trigger was great), the third round was a FTF. I ejected the round and saw a primer strike dimple. The third round double fired....oh, oh. I had the gun firmly to shoulder so I discounted a possible bump fire. The fifth round fired normally, but, the sixth and seventh also had FTF. I experienced another double fire, another FTF and a couple of normal firings. I quit shooting 15 rounds into the first magazine with 4 or 5 rounds that were FTF.

I removed the bolt group and noticed that with the bolt all the way back to where the cross pin is all the way back in the groove, the firing pin is partially exposed (about 15-20 thousandth of an inch). I originally thought that I had a bad batch of ammo and that some of the rounds didn't fully chamber, but that doesn't explain the double firing incidents.
I can't imagine that Geissele trigger group is the source of the problem. If the spring was too light, I shouldn't have had the double fire incidents. Anyone have a clue?
 

·
Registered
Joined
·
465 Posts
Not sure about the firing pin portrusion but this was just covered a few days ago with same symptoms, what was diagnosed is a problem with the grip screw. You have to use the provided grip screw and not the oem version its too long.
 

·
Registered
Joined
·
6,616 Posts
I would fix that asap. "Double firing" is very bad juju with the authorities and could land you in a heap of trouble. Try the grip screw thing.
 

·
Registered
Joined
·
6,441 Posts
When I installed the Geissele in my 16s, I had to file the grip screw down. There's a channel in the trigger module where the grip screw protrudes and the trigger group sits directly above it. You need to make absolutely certain the screw does NOT extend above that channel. As Kam states, you definitely don't want to emulate a full-auto weapon for ANY reason without the proper credentials.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #5
I recognize that "double firing " can cause serious legal issues (let alone safety issues). I found the previous thread and, yes, I did install the Geissele black screw and it is not protruding into the main housing. I did notice that I don't feel a distinct second stage, however. I will contact them tomorrow and ship them the lower grip assembly for them to verify and QC. Thanks for the heads up. I hope this is the root of the problem.
 

·
Registered
Joined
·
25,418 Posts
Did you try feeding the weapon any other ammunition besides the Fusion stuff to isolate the issue to the trigger mechanism instead of the ammunition primer sensitivity being the culprit?

FTF: Failure to fire, or failure to feed? Please expand on this in detail.

-SS
 

·
Registered
Joined
·
11 Posts
Discussion Starter #7
Did you try feeding the weapon any other ammunition besides the Fusion stuff to isolate the issue to the trigger mechanism instead of the ammunition primer sensitivity being the culprit?

FTF: Failure to fire, or failure to feed? Please expand on this in detail.

-SS
Failure to fire. All five rounds show a decent primer strike. My concern is with the firing pin being exposed by 15-20 thousandth with the bolt all the way back in the bolt carrier (I am not sure what position it is when a round is chambered). If the pin was already resting or denting the primer when the bolt is closed, the hammer may not have sufficient momentum to fire the primer (which is already compressed by the bolt closing). It doesn't seem right that something is out of spec, so I might be off base here. I did not have any other brand of ammo with me at the time. Fortunately, this private range is owned by my friend who is a gunsmith. He was very concerned, but, I did not want to take too much of his time, as we were there with a couple of other guys and a dozen rifles to put through their paces.
The other threads appear to point to an issue with the trigger group installation ( even though I do not have a grip screw issue, as I can see 3-4 empty threads exposed in the plastic of the floor plate). I will ask Gissele to verify my installation, just to try to rule it out. If the lower comes back ok. I will check it out with the same brand of ammo and some others to try to get to the root of the problem.
 

·
Registered
Joined
·
25,418 Posts
Appears to be an ammunition issue.

The firing pin protrusion is normal. The only issue is if the firing pin protrusion was too short, which results in a failure to fire.

Swap out the ammunition and have another go at it. If the same issue is present, call FN USA's service department.

Knowing all FN weapons are test fired prior to shipping, a firing pin/bolt issue would have been identified prior to the weapon being packaged and shipped to the distributor.

-SS
 

·
Registered
Joined
·
602 Posts
I have had similar problems with federal soft point ammo. Try some FMJ ammo or another load and see your results. Is that ammo soft point?
 

·
Vendor
Joined
·
1,754 Posts
Usually in life, only one problem appears at a time, so all symptoms have to fit together to point to a single root cause.

In this case, it might not be true. I can think of several causes for failure to fire, from drag in the hammer, to bad ammo, and I can think of several causes for doubling, like the grip screw or a bad/missing spring in the disconnector. But I can't think of any single issue that would cause both - unless your cat is sneaking into your gun collection at night and intentionally messing with stuff.

If you continue to have issues with failure to ignite, I do sell a higher energy hammer spring, however that does not address the issue that it 'ought' to work with the regular hammer spring.

Actually, I can think of one thing - a long shot. If your hammer is binding on the pin somehow, it might not swing back freely to engage the disconnector properly, and it might be dragging going forward so it is losing energy. It's a long shot, but I'd pull the hammer spring, and just work it back/forth to make sure it is moving freely.
 

·
Registered
Joined
·
77 Posts
When I put a geis trigger on my 17s it did the same thing. Sent it to geis and they sent it back the next day. That fixed it
 

·
Registered
Joined
·
11 Posts
Discussion Starter #12
When I put a geis trigger on my 17s it did the same thing. Sent it to geis and they sent it back the next day. That fixed it
Thanks guys,
I had a very enjoyable talk with the nice people at Geissele this morning. I will be shipping them the lower unit tomorrow for them to inspect/repair if necessary. Once we rule that out, I will try to shoot the remainder of the case to see if there are any more hiccups. I will also shoot a few boxes of other brands of ammunition to try to rule out Federal as being the issue as well. Lastly, if both approaches prove inconclusive ( and I am leaning on the trigger/my installation as the culprit for now), I will ship the entire rifle back to FN ( they will probably expect the stock trigger group reinstalled).
Stay tuned and I will report my findings.
 

·
Registered
Joined
·
230 Posts
Lastly, if both approaches prove inconclusive ( and I am leaning on the trigger/my installation as the culprit for now), I will ship the entire rifle back to FN ( they will probably expect the stock trigger group reinstalled).
Stay tuned and I will report my findings.
Hopefully the guys at Geissele will find and correct the issue for you. If, that does not correct the problem and you are left with having to resort shipping the rifle back to FN, I would first recommend placing the stock trigger back in the housing and shooting again to see if the problem is gone or still persists. In fact, if you have the time before shipping the lower, you can try switching the trigger back to stock to see if the Geissele install is the culprit or the ammo.

Good Luck and hope it all works out
 

·
Registered
Joined
·
1,861 Posts
I'm getting anxious for the shooting sight trigger. I had a couple of other purchases I've recently done because of short windows of opportunity for the items/price. But yes, I'm definitely going Shooting Sight..support a forum vendor, and that new higher energy spring has got my attention. And I'm not knocking Geissele, I've heard great things about them...but I can spell Shooting Sight so much easier lol. Looking forward to updates on this thread...sometimes curiosity just peaks with some topics ya know.
 

·
Registered
Joined
·
28 Posts
Interesting… So aside from the T and G triggers, there’s an adjustable 3rd S trigger.
A double-strike is unacceptable, I’d retain the stock FN trigger first.
 
1 - 17 of 17 Posts
Top