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M4 Disconnector Problem?


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I just bought an M4. Installed a Hammer, Trigger, Disconnector from FFT. Seems to function (dry fire) fine. When I try to float a (dummy) round the hammer won't drop. It seems by pulling the bolt back just enough for the chambered round to be able to be manipulated down to clear the bolt resets the disconnector. No matter how careful I am not bringing the bolt too far back. Is this normal or could I have screwed up something in the trigger group install?

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The pictures helped a lot. The hammer is hanging up on the disconnector. When the trigger is let go, the hammer hook should come off the disconnector and engage the trigger hook. So either;   1. Th

Update: A&S trigger guard ordered 😃 Thanks for helping me “pull the trigger” on that 👍🏼

I had the same issue with the Polymer trigger housing and switched to the aluminum one and the FFT trigger worked fine. 

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Can you take pictures of the trigger pack? I'm not sure what you mean by saying you were having issues with floating a round. You mean having a round chambered, and another round on top of the elevator?

 

You could try dropping the stock parts back in one at a time and performing the function check. I'd start with the hammer. Then do the disconnector. Then the trigger. If it still doesn't work, try it with the stock parts. If it still does not work, something may be reassembled incorrectly.

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Can you take pictures of the trigger pack? I'm not sure what you mean by saying you were having issues with floating a round. You mean having a round chambered, and another round on top of the elevator?

 

You could try dropping the stock parts back in one at a time and performing the function check. I'd start with the hammer. Then do the disconnector. Then the trigger. If it still doesn't work, try it with the stock parts. If it still does not work, something may be reassembled incorrectly.

 

Yes, I do mean a round in the chamber and another on top of the elevator, this "seams" to be engaging the disconnector. When this happens, I cycle the bolt, it ejects the chambered round and loads the round that was on top of the elevator and the hammer still won't drop...then, only when the magazine is empty and the bolt is locked to the rear, I can push the bolt release and the hammer will drop. Here are pictures with the hammer cocked, disconnector engaged, hammer forward.

[ATTACH=CONFIG]1378[/ATTACH]

 

[ATTACH=CONFIG]1379[/ATTACH]

 

[ATTACH=CONFIG]1380[/ATTACH]

 

I just noticed something...I lock the bolt back, drop a shell in, drop the bolt closed, load dummy rounds in the magazine, press the trigger and the hammer falls, manually cycle, ejects chambered round and loads a round in the chamber, hammer will not fall, press cartridge drop lever, cycle again, ejects and loads another round, hammer will not fall, cycle bolt and cartridge drop lever until magazine is empty and bolt locks to the rear, press bolt release and hammer drops. This sounds like "operator error" (Meaning I did something wrong replacing the hammer, trigger, disconnector. It seamed pretty straight forward and pretty easy). Or is this how the gun is supposed to function dry firing and manually cycling using dummy rounds?

 

If the pictures don't offer any clues, I will post of video. This is my first Benelli so, I (obviously) am a newbie. I'm learning as much as I can, this forum is certainly a big help. Thanks!

Edited by Stevejg16
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The pictures helped a lot. The hammer is hanging up on the disconnector. When the trigger is let go, the hammer hook should come off the disconnector and engage the trigger hook. So either;

 

1. The hammer is out of spec (possible but unlikely)

2. The Disconnector is out of spec (Unlikely)

3. The trigger is out of spec. Or, it is possible that the trigger spring is not installed correctly.

 

I would install the factory hammer and see if the issue still exists. If the problem is still present, pull the trigger pack out and verrify that the spring is seated correctly and functioning. The spring should be returning the trigger to its forward position. If you can manually pull the trigger forward, there is something wrong. Listen to hear if the disconnector is disengaging and allowing you to pull the trigger normally.

 

If the spring seems fine, swap to the stock disconnector on the FFT trigger and try again. If the problem still exists, swap back to the stock trigger.

 

The goal is to determine which part is causing the problem.

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The pictures helped a lot. The hammer is hanging up on the disconnector. When the trigger is let go, the hammer hook should come off the disconnector and engage the trigger hook. So either;

 

1. The hammer is out of spec (possible but unlikely)

2. The Disconnector is out of spec (Unlikely)

3. The trigger is out of spec. Or, it is possible that the trigger spring is not installed correctly.

 

I would install the factory hammer and see if the issue still exists. If the problem is still present, pull the trigger pack out and verrify that the spring is seated correctly and functioning. The spring should be returning the trigger to its forward position. If you can manually pull the trigger forward, there is something wrong. Listen to hear if the disconnector is disengaging and allowing you to pull the trigger normally.

 

If the spring seems fine, swap to the stock disconnector on the FFT trigger and try again. If the problem still exists, swap back to the stock trigger.

 

The goal is to determine which part is causing the problem.

 

 

Before I even get home and check the info you gave me, I'm thinking it's going to be the trigger spring. I thought it went into the "hole" just forward of the "trigger". I can't tell from the schematic, can you please explain the positioning of the trigger spring in reference to where it lies against the trigger and inside the trigger guard? Thank you for your time!

 

UPDATE...... The FFT Trigger Group didn't work for me. Changed back to factory Parts, no problem. I'll let everyone know how the customer service is at FFT. i'm just disappointed parts would get sent to a customer like this.

 

Just talked to Todd from FFT, called me back in two minutes after I sent him an email. He is sending another trigger group to

me immediately. He's confident that his parts are spec, this is the first problem he has heard about. Great customer service.

Edited by Stevejg16
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The trigger spring does go in that hole in the base of the trigger. If you pushed the trigger all the way forward, would the disconnector disengage?

 

Since the factory FCG works, this alludes to the fact that nothing else is wrong with the weapon.

 

Good to hear that FFT is sending you a new set to try.

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The trigger spring does go in that hole in the base of the trigger. If you pushed the trigger all the way forward, would the disconnector disengage?

 

Since the factory FCG works, this alludes to the fact that nothing else is wrong with the weapon.

 

Good to hear that FFT is sending you a new set to try.

 

There was no forward play in the trigger at all. I've learned so much in a few days. If the new FFT trigger group gives me the same problem I'll have to look for another supplier. But, will always appreciate the customer service he gave me.

 

"StrangerDanger", thanks for your input. I would still be wondering WTF. I'll post my results. Still waiting for my Titanium one piece extended magazine from FFT so, I do have some time to comply with 922r.

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Have you tried installing say just the hammer and testing it to see if the failures happen? Also, you'll want to apply a small amount of grease to the sear contacts for optimal performance.

 

Basically, when the weapon fires and you hold the trigger to the rear, the hammer is cocked by the cycling bolt carrier. The discconnector then engages because the hammer is still pulled to the rear. This prevents the hammer from just falling again aas the bolt carrier cycles forward since the trigger is still pulled. As you let off of the trigger, the hammer hook disconnects from the disconnector and engages the trigger hook. The hammer is then ready to fall when the trigger is pulled again.

 

Your hammer should never be held by the disconnector when the trigger isn't pulled to the rear. This is where your problem resides.

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Have you tried installing say just the hammer and testing it to see if the failures happen? Also, you'll want to apply a small amount of grease to the sear contacts for optimal performance.

 

Basically, when the weapon fires and you hold the trigger to the rear, the hammer is cocked by the cycling bolt carrier. The discconnector then engages because the hammer is still pulled to the rear. This prevents the hammer from just falling again aas the bolt carrier cycles forward since the trigger is still pulled. As you let off of the trigger, the hammer hook disconnects from the disconnector and engages the trigger hook. The hammer is then ready to fall when the trigger is pulled again.

 

Your hammer should never be held by the disconnector when the trigger isn't pulled to the rear. This is where your problem resides.

 

I did try just installing the factory hammer, same problem. These parts layed on top of each other look identical but, something has to be off somewhere by a few thousandths. Todd at FFT is baffled by this since all his parts are CNC'd (terminology?). We'll see if the trigger group he is shipping will do the trick. I hope so, I need those three parts for compliance.

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I'm sure this will get straightened out. The disconnector appears to be barely hanging on your hammer hook. The finish was probably a little heavy on it which is causing it to hang up. Since the hammer isn't the issue, it'll be on either the disconnector or the trigger itself as being out of spec.

 

When the hammer hook pushes down, it hits the disconnector. This is why it has the spring loaded detent. This allows the disconnnector to be pushed back slightly to allow the hammer to pass by, then engage the disconnector hook as long as the triggger is pulled to the rear. It appears to be catching on the disconnector even with the trigger released.

 

If you pull the trigger pack out, and cycle the hammer by hand, did it hang up on the disconnector?

 

There are always what are called tollerance stacking events for any mechanical device. No matter how precisely made. It is difficcult to control the tollerances on a finish.

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I'm sure this will get straightened out. The disconnector appears to be barely hanging on your hammer hook. The finish was probably a little heavy on it which is causing it to hang up. Since the hammer isn't the issue, it'll be on either the disconnector or the trigger itself as being out of spec.

 

When the hammer hook pushes down, it hits the disconnector. This is why it has the spring loaded detent. This allows the disconnnector to be pushed back slightly to allow the hammer to pass by, then engage the disconnector hook as long as the triggger is pulled to the rear. It appears to be catching on the disconnector even with the trigger released.

 

If you pull the trigger pack out, and cycle the hammer by hand, did it hang up on the disconnector?

 

There are always what are called tollerance stacking events for any mechanical device. No matter how precisely made. It is difficcult to control the tollerances on a finish.

 

 

Yes, the trigger does hang up on the disconnector with the trigger pack out.

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Great to hear. Function test the **** out of it. I'd even jolt it on the rubber butt pad on the ground. So do you have to mail the defective ones back?

 

I will do that. I did mail back the other parts and inavertantly sent him the Factory Trigger, we'll swap the parts in the mail. He is still not sure anything is wrong. After becoming an expert in changing the trigger group out (about 10 times) I think the disconnector was sitting forward just enough to catch.

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  • 7 years later...

Hey everyone. I’ve been reading a lot on this forum for awhile now (lots of old but useful info here so thanks!) and this is my first post.

So here I am, reviving an old post but I’m having almost the exact same issue with the disconnector. I sent an email to FFT (below).

“Hello. I recently ordered the trigger kit for my Benelli M4. After installing and performing numerous function checks, I noticed that there was no audible click when slowly releasing the trigger after dry firing and holding the trigger to the rear. After visually inspecting what was going on, it seemed that the hammer would go past the disconnector and get hung up (beyond the disconnector “lip”). If I didn’t push the hammer too far (just enough to clear the disconnector), the hammer would catch the disconnector but after releasing the trigger it would still be slightly caught on the disconnector. I then replaced the disconnector with the factory one and had no issues. I took a few photos/videos comparing how each disconnector sits in the FFT trigger and it seems that the FFT disconnector sits too far forward causing the hammer to get hung up. Can I exchange the disconnector for another one? Thank you”

And this is their reply:

“There won't be any difference between one disconnector and another - they're all cut on highly precise EDM machines and for all intents and purposes all disconnectors are mirror images of each other.  Additionally, I don't have another disconnector to give you - we're out completely - even if I thought that would make a difference.

But just because your disconnector seems to be sitting too forward doesn't mean it isn't an issue with the trigger, the plunger, one of the springs, or the trigger housing.  If the trigger is sitting a hair forward it could cause that issue.  I get that with the OEM seems to be working but then the OEM could be milled slightly out of spec to compensate.

We've found over near 10 years of doing Benelli trigger kits that the OEM components over the years vary and we see a lot of components out of spec.  

Really the only thing I could do is take the trigger kit back for a refund.  We don't sell any of the three components individually, so if you'd like to return the kit it would need to be the kit in its entirety.  

Please let me know if that's what you'd like to do and we can arrange a return.  You can call call me at the number on the website to discuss if you'd like.”

So now what do I do? I’m trying to keep the gun compliant and would like to have a couple extra “compliant parts” installed AND still use all 3 parts that I paid for.

AD0FC2B4-EA04-41C9-BBEE-886C58331D58.jpeg

78D41F1C-8D9D-4FA1-9444-96487D7F78C0.jpeg

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I can confirm that often times it is the Benelli trigger frame that is out of spec. Either the trigger pins or the hammer bushing pin isn’t located perfectly where it needs to be. Giving more fore or aft positioning for the trigger/disconnector. 
 

What you could try is to buy the A&S trigger frame and drop these components into it. These are better made than the OEM and it would get you another US made part. 

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22 minutes ago, StrangerDanger said:

I can confirm that often times it is the Benelli trigger frame that is out of spec. Either the trigger pins or the hammer bushing pin isn’t located perfectly where it needs to be. Giving more fore or aft positioning for the trigger/disconnector. 
 

What you could try is to buy the A&S trigger frame and drop these components into it. These are better made than the OEM and it would get you another US made part. 

That does make sense seeing as my trigger assembly is the polymer one. The A&S trigger guard was on my shopping list but was going to do a couple other things first. I may have to move that up now.

Thanks for the reply SD!
 

 

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Interesting. Most of the issues I’ve seen were on the old cast aluminum frames. 
 

If the issue is still present, I’d gladly take a look at it for you. I have enough new parts for the trigger pack to identify exactly where the out of spec part is. 
 

It is possible that the FFT part is out of spec. Either way you’ll be happy to have the A&S frame. 

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1 minute ago, StrangerDanger said:

Interesting. Most of the issues I’ve seen were on the old cast aluminum frames. 
 

If the issue is still present, I’d gladly take a look at it for you. I have enough new parts for the trigger pack to identify exactly where the out of spec part is. 
 

It is possible that the FFT part is out of spec. Either way you’ll be happy to have the A&S frame. 

We'll see what happens after I transfer over all the guts to the A&S.  The biggest thing I noticed when changing out the OEM parts for the FFT kit multiple times to test what was going on and narrow it down was it was a real PITA to install the disconnector pin through the FFT disconnector (the process w/ that part is already hard but I mean physically getting the pin through the disconnector hole).  Went in pretty easy on the OEM disconnector (didn't really even need a punch to get it all the way through).  I also stacked the 2 disconnectors and the holes didn't seem to line up perfectly (just by visual inspection, tried to get them perfectly stacked to take a look through).  Other than that, everything else was pretty straight forward swapping out the parts.

Come to think of it, Todd did mention spring tension, so I may try to swap disconnector spring to the OEM one when I get home just to rule that out for now to see if that helps. But maybe since the holes are either not aligned the same, the OEM spring might help bring the FFT disconnector back some, giving the hammer a hair more clearance.

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Maybe run a punch down the hole of the trigger to make sure there is no burs or weird seat depth for the spring. Double check the position of your trigger spring too. Are you using OEM springs or some aftermarket kit?

The OEM and FFT disconnector will look slightly different. The OEM has softer edges which can make lining the parts up difficult. The best way to align them for comparison is to run a proper sized punch or drill bit through the bottom pin holes of both.

 

That disconnector pin is a pain to get in due to how small it is. The recent FFT pins have very very tight. You’re right about OEM just pushing in with your finger. 
 

Check your trigger pins to make sure you have the shell release spring seated right on the front pin and the rear pin is installed correctly to permit the trigger to rock back and forth as intended. 
 

I’d put a small drop of grease on the sear contact points as well. 

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4 minutes ago, StrangerDanger said:

Maybe run a punch down the hole of the trigger to make sure there is no burs or weird seat depth for the spring. Double check the position of your trigger spring too. Are you using OEM springs or some aftermarket kit?

The OEM and FFT disconnector will look slightly different. The OEM has softer edges which can make lining the parts up difficult. The best way to align them for comparison is to run a proper sized punch or drill bit through the bottom pin holes of both.

 

That disconnector pin is a pain to get in due to how small it is. The recent FFT pins have very very tight. You’re right about OEM just pushing in with your finger. 
 

Check your trigger pins to make sure you have the shell release spring seated right on the front pin and the rear pin is installed correctly to permit the trigger to rock back and forth as intended. 
 

I’d put a small drop of grease on the sear contact points as well. 

Yeah, I'm probably going to tear it down again and check the spring holes (I'm pretty sure everything was good).  I'm using the springs that came with the FFT trigger kit. Going to try switching the disconnector spring back to the OEM spring and see what happens.  Not sure if the FFT trigger kit was supposed to come with another disconnector pin but mine didn't so I don't know if that would make a difference.

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