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Benelli M4 -- Trigger, Disconnector and Hammer Disassembly


StrangerDanger

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I have about 800 - 1,000 rounds through the FTT Trigger and Disconnector. Around 1,500 - 1,800 on the Geiselle Hammer. The trigger is certainly an improvement over stock. The parts are pretty inexpensive too. The trigger break is much more crisp and certainly lighter -- for what that matters on a shotgun.

 

The Starrett punches are nice, I wish they made a set that was about 50% longer though. It seems almost every job I run into runs the punch right up to the taper.

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If you need longer punches, parallel, roll pin, or roll pin holders........you can easily fabricate your own.....use the desired size drill rod stock, and simply modify a brass punch to insert the drill rod into......here's an example of such a good looking punch. This one I use for removing AR bolt latch pins, as I really don't care for the 1/2 diameter variant that is often recommended. This particular punch is also handy to remove the carrier latch button roll pin on the Benelli's which require a long reach to prevent scratching the receiver with the shoulder of shorter punches.

eee6ea48.pnge0bf7128.png

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  • 3 weeks later...
  • 3 months later...
  • 1 month later...

This deserves a bump, it is an excellent step-by-step tutorial. Far more detailed than I needed, but these instructions are so thorough, they should allow nearly anyone to do this job with just a few simple tools. Thanks Stranger Danger.

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Thanks.

I have been thinking about expanding this tutorial so it goes through tearing down the trigger group completely. The rest isn't that difficult once you've been through it once.

 

I tore my M4 completely down for refinishing about two or three weeks ago. I think I disassembled the entire trigger pack in about five minutes.

 

I added a few tools to my stable recently. I bought a set of extra long Starrett drive punches. These have pretty limited value though since they're 1/8", 3/16", 1/4", 5/16", and 3/8". That seems small, but most of the pins you encounter on firearms are below 1/8".

 

It's really easy to snap the smaller punches. Longer length models are even more prone to this. I looked up Wiha, but didn't really see any that seemed significantly longer. The metric set does look nice, but I'd like to get something with a longer shank size than the Starrett set. On my DDLES AR15 Glock lower, there are several deep seated pins that I ended up having to tap out with an old drill bit. 'Bubba Smithing' and OCD don't get along well.

 

I did add a set of long shank Bondhus allen wrenches in both metric and standard sizing. I foresee them getting used a lot on these firearms. Typically any bit that requires you to remove the wrench and reposition 180 degrees is eliminated. Once you get it tight, you can move in with a shorter bit for more torque control.

 

I bought a set of Channellock snap ring pliers, the 8" 927 model. Not sure if I like them or not. The tips come together at an angle, so when you're picking up the snap ring, the ring wants to slide off the end of the tips. The 90 Degree angled tips are less pronounced in this.

 

I have my eye on a Seekonk dial indicator torque wrench this week. I want one in the 1 - 100 foot pound range. I have one of their smaller units that is rated at 1 - 75 inch pounds. It adapts to all the Magnabits I have. Love it. I hate the clicker torque wrench I have. I have a yard time trusting it.

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SD,

 

You can fabricate the length and diameter punches you need very easily. Still will need to use starter punches etc. with the longer pins so you don't bend / break them as you mentioned......sometimes you need to use a series of punches of slightly different lengths to remove a long pin from a tight host hole, otherwise the punches will fail.

 

Screenshot2013-03-07at110425AM_zps655ee529.png

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Seems those Wiha's are a little longer. Might have to get a set of those.

 

How exactly are you making the handles? Are you just putting the brass punch in a drill press vice, and boring the appropriate size hole for the desired diameter drill bit? How did you put that nipple on the end of the drill bit? I assume that was done with a lathe? Did you bore down a specific depth? It seems the deeper the better, so long as you don't get close to the bottom.

 

Looks like you cut the drill bit with a lathe too?

 

I'm really surprised that someone doesn't sell a set of long drive punches. Brownells sells a Grace punch that is 5/16" diameter. It seems like it would be a decent host for the rods. Here are the rod's I assume you used?

 

http://www.brownells.com/gunsmith-tools-supplies/small-hardware/metal-stock/water-hardening-drill-rod-prod585.aspx

 

This is a pretty good deal. You could get 18 drive punches at small incremental size bumps. Since the rod is 18" long, you'd have plenty of spares, or the capacity to make various lengths.

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Seems those Wiha's are a little longer. Might have to get a set of those.

 

How exactly are you making the handles? Are you just putting the brass punch in a drill press vice, and boring the appropriate size hole for the desired diameter drill bit? How did you put that nipple on the end of the drill bit? I assume that was done with a lathe? Did you bore down a specific depth? It seems the deeper the better, so long as you don't get close to the bottom.

 

Looks like you cut the drill bit with a lathe too?

 

I'm really surprised that someone doesn't sell a set of long drive punches. Brownells sells a Grace punch that is 5/16" diameter. It seems like it would be a decent host for the rods. Here are the rod's I assume you used?

 

http://www.brownells.com/gunsmith-tools-supplies/small-hardware/metal-stock/water-hardening-drill-rod-prod585.aspx

 

This is a pretty good deal. You could get 18 drive punches at small incremental size bumps. Since the rod is 18" long, you'd have plenty of spares, or the capacity to make various lengths.

 

I have some of the same questions and thoughts.

 

I'd be more than willing to chip in some money to fabricate a set of useful long punches if someone wants to head up the effort (hint, hint). I'd pay in advance to fund the materials/effort.

 

I might still buy the Wiha metric set (I like Wiha and their punches appear to be nice and a little longer but nothing smaller than 2mm)

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Guys,

 

I use a dremel cut-off wheel to reduce the brass punch; mount the punch in vise and slightly under drill the desired drill rod diameter into the brass punch handle; that usually is snug enough when the punch is gently tapped onto the drill rod. On occasion I use some JB Weld 2-part epoxy to bond the drill rod with the brass punch.

 

For the drill rod I use the water-hardened type:WATER HARDENING DRILL ROD | Brownells

not the oil-hardened rod.

 

I don't need a lathe to turn the tip of the drill rod for the roll pin punch tip; I chuck the drill rod into a drill press (before installing in the brass punch handle) and rotate it at slow speed and use nice gunsmith file to turn the tip down to the size you desire; there isn't much force on the nipple geometry of a roll pin punch, but if you wanted to re-heat the rod tip to temper / harden and quench it in water.

 

The working diameter of the Wiha punches are ~ 30% longer than the Starrett's.

Edited by benelliwerkes
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I might take one this task. I've always wanted a basic small lathe. A lathe would be the proper tool to do this. Using the brass handles is a smart method of getting to avoid doing knurling detail.

 

I have limited experience with a lathe, but I know the basics. Roll the carriage up to the brass handle and taper the end some and make sure the face is concentric and set to a uniform length. With the cut off brass handle in the chuck, and a drill bit in the tailstock, this would drill a hole perfectly in the center.

 

Maybe stamp the side with the rod's size. That would be pretty easy on the brass. Maybe get a derlin board and bore some holes evenly spaced out for the brass base to fit in.

 

I bet a few would be willing to buy such tools.

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  • 2 weeks later...

Hello, new to the forum. Could you do me a favor? I just installed the FFT disconnector and hammer in my M2. What I am noticing is that the new hammer when not cocked is loose - flopping back and forth. Is this the same as in a stock M2? I don't remember how the hammer was before I changed it out. Maybe I installed something wrong?

 

So the short question is: Does your un-cocked hammer flop front to rear about 1/4 inch?

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I've never had a M2 to disassemble. However, I looked at the Freedom Fighter Tactical website and it does not say if the trigger components will work with the M2 or not. What I would do is, I would pull out the FFT hammer, and install the OEM unit. Compare the movement between the two to see if there is any change in operation.

 

The trigger and disconnector should have no effect on the hammer when the hammer is forward.

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I've never had a M2 to disassemble. However, I looked at the Freedom Fighter Tactical website and it does not say if the trigger components will work with the M2 or not. What I would do is, I would pull out the FFT hammer, and install the OEM unit. Compare the movement between the two to see if there is any change in operation.

 

The trigger and disconnector should have no effect on the hammer when the hammer is forward.

 

Thanks for the reply. I bought the FFT components for the M2. I will replace the OEM hammer and check function. The tutorial for the M4 as compared to an M2 is almost identical except the snap ring is different and the M4 trigger is 'open' as the M2 has sides (more plastic) around the disconnector parts.

 

Thanks

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