Benelli M4 -- Rear Sling Plate Removal

[StrangerDanger]

This tutorial will focus on the removal of the Benelli M4 field and pistol grip stock’s sling plate. A big thanks goes out to Benelliwerks to advising me how to get the assembly apart a few years back. I just finally figured out how to actually do it.

As you can see by the Benelli diagram above, both the field and the pistol grip stock are assembled the same way with the same components when it comes to the rear sling mount.

 

Remove the Recoil Pad (061C) from the stock by unscrewing the two self-tapping screws (062J) that are accessed from the two small holes at the rear of the Recoil Pad (061C).

Note: You’ll want to use a fixed blade Philips screw driver. Use a little oil or spit on the small opening at the bottom of the recoil pad. Press the screw driver into the hole until you feel it engage the screw bit.

Edited December 14, 2015 by StrangerDanger

[StrangerDanger]

 

You can see here that the screws are the self-threading type. Be careful with these on the pistol grip and field stocks. It is easy to strip out the holes in the stock.

 

Next, look down inside the bottom of the stock and note the 13mm Stock Retaining Nut (053J). I personally prefer to put the stock in a padded vice. Having it in a vice will give you more hands to work with. Naturally you do not want to crush your stock with the vice, so use your best judgment.

 

 

Note: I’ve shown how the hardware is assembled in the bottom right corner to give you a visual reference to what you’re working on.

 

You're going to need a heat gun, because those evil Italians locktited the crap out of the threaded portions of the Stock Retaining Pin (280J). You're going to want to focus your heat through the bottom end of the butt stock on the 13mm Stock Retaining Nut (053J). Apply enough heat to let the locktite give way and remove the 13mm nut. I run the heat gun for approximately thirty seconds, and try to unscrew it. You do not want to use retard strength on this. If you try to force it, you’ll see that you’re jamming the wing of the Stock Retaining Piece (278J) into the inner body of the stock. Once the Stock Retaining Nut (053J) begins to move, the battle has been won. Remove it completely from the stock. Be careful with it though, it will likely be hot.

[StrangerDanger]

 

Note: Application of heat.

 

[StrangerDanger]

 

Note: I’ve shown the orientation of the Stock Retaining Pin (280J in the bottom right corner of the image.

 

 

Note: The removed 13mm Stock Retaining Nut (053J).

Edited December 14, 2015 by StrangerDanger

[StrangerDanger]

At this point, I like to move the stock to nearly a horizontal position in the vice. It will help with putting the nut in place.

 

 

 

Insert your 13mm nut into a 13mm deep socket with a 10 inch extension.

[StrangerDanger]

Next, look down the front end of the stock with a small flash light. Notice the threaded portion in the center of the stock. This is what the stock screws into the receiver extension by.

 

 

Next, tighten the 13mm Stock Retaining Nut over this end of the Stock Retaining Pin (280J). You want to tighten this firmly.

 

 

Note: Here is the nut tightened. The purpose for this is to use this nut to give you leverage on the Stock Retaining Pin (280J) so that you can unscrew it.

[StrangerDanger]

 

More heat is needed on the Stock Retaining Piece (278J). Every 20 or 30 seconds, attempt to unscrew the Stock Retaining Nut (053J) slowly while looking through the end of the butt-stock. You want to see if the Stock Retaining Pin (280J) is unscrewing from the Stock Retaining Piece (278J). If the Stock Retaining Nut (053J) simply loosens and begins to unscrew off of the Stock Retaining Pin (280J), re-tighten it and apply more heat to the Stock Retaining Piece (278J). Repeat this process until you can see the Stock Retaining Pin (280J) is unscrewing.

 

 

The Stock Retaining Piece (278J) and the eight Field Stock Retaining Springs (279J) will fall out the end of the butt stock as the Stock Retaining Pin (280J) is removed.

[StrangerDanger]

 

Next, tip the stock forward and allow the Stock Retaining Pin (280J) and the Stock Retaining Nut (053J) to fall out the front. The Stock Retaining Nut (053J) will still be attached to the Stock Retaining Pin (280.)

 

 

At this point, the Sling Plate (063J) will simply pull out either side of the stock.

[StrangerDanger]

 

Sling Plate (063J) Removed.

 

 

I recommend that you remove the Stock Retaining Nut from the Stock Retaining Pin since you don’t want to have the nut stuck on the pin. At this point, you probably have the nut jammed on pretty tight.

[StrangerDanger]

 

Put the Stock Retaining Pin and the Stock Retaining Nut combo into the vice carefully. Try not to mar up your work. I find an angled approach in the vice works best to avoid the raised surfaces on the Stock Retaining Pin. Apply heat to the Stock Retaining Nut and unscrew it from the Stock Retaining Pin.

 

 

At this point, your Stock Retaining Pin free to be cleaned up with a wire brush to remove all of the factory thread locker.

Edited December 14, 2015 by StrangerDanger

[StrangerDanger]

 

Here is a photo showing the sling mount assembly overlaid on the stock.

 

Now for reassembly, most of the reverse installation is pretty self-explanatory. There is one area that can cause grief though. You need to screw the Stock Retaining Pin in through the assembly and into the Stock Retaining Piece. The problem is, there is nothing to hold the Stock Retaining Pin by as you thread it in deep inside of the stock. This is how I do it. I have two of the Stock Retaining Nuts on hand. I screw the first Stock Retaining Nut onto the Stock Retaining Pin as shown below.

 

 

You want to gently screw the Stock Retaining Pin into the Stock Retaining Piece with the aid of the Stock Retaining Nut and your 13mm deep socket driver. You don’t want to crank on this, because you’re going to need to get that nut back off. Once you’ve seated the Stock Retaining Pin all the way, install the second Stock Retaining Nut onto the recoil pad side of the Stock Retaining Pin. Tighten this nut firmly in place. At this point, you should be able to unscrew the first Stock Retaining Nut without risk of the Stock Retaining Pin moving.

 

I would apply Locktite primer and blue Locktite to the threaded portion of the Stock Retaining Pin that the Stock Retaining Piece and permanent Stock Retaining Nut attach to. Do not put Locktite on the portion that screw into the receiver extension.

The Stock Retaining Pin is 8mm in diameter x 1mm thread pitch. A nylon lock nut is ideal for using as a slave nut.

[StrangerDanger]

I started working on this before Benelliwerkes was nice enough to post his tutorial from his manual. Anyone notice I got a new camera? Eyephone 6S takes decent pictures!

Edited December 14, 2015 by StrangerDanger

[benelliwerkes]

....You don’t want to crank on this, because you’re going to need to get that nut back off. Once you’ve seated the Stock Retaining Pin all the way, install the second Stock Retaining Nut onto the recoil pad side of the Stock Retaining Pin. Tighten this nut firmly in place. At this point, you should be able to unscrew the first Stock Retaining Nut without risk of the Stock Retaining Pin moving.

 

 

Once the stock retaining nut is secured to compress the springs against the threaded stock retaining plate, the threaded bolt cannot turn anymore as in order for it to happen, the stock retaining nut would have to be ripped off the other end of the bolt; it is this configuration that allows the slave nut to be unscrewed without fear of the bolt turning during the process.

 

Same principle as using a double-fisherman's knot to secure to mountaineering ropes together; opposing knots cannot pull thru each other.

 

Photo by permission: Anatomy Series Manuals

Edited December 14, 2015 by benelliwerkes

[madisonapahe]

Thank you for the instructions and pics Stranger. Other sites said the plate was welded to the bolt and not to try it or you will damage the stock. I followed your directions and it was very easy. Hats off to you sir

[StrangerDanger]

Glad it helped!

[benelliwerkes]

........Other sites said the plate was welded to the bolt and not to try it or you will damage the stock........

 

They are idiots promulgating stupidity.

[StrangerDanger]

I heard that same wives' tale about removing the receiver extensions.

[DingleBerry]

I removed my original end plate using this similar method and installed a Noveski QD end plate.

The only thing different I did was I double nutted the the pistol grip side and then locking the two 8 mm nuts together

I was able to use a ratchet, extension &  (13MM) socket to back the stud out from the pistol grip side of the stock.

These pictures and diagrams were very helpful in figuring out how to dissasemble.

Thanks so much! 

[DingleBerry]

I also did not need a vise, or a heat gun.  My aircraft plastic nut was not that difficult to remove.  It did have some locktite on the stud threads

I cleaned off the old loctite and I will not locktite a plastic nut for reassembly. I feel this is not necessary for an aircraft plastic nut.

I am going to install a Limb saver new butt stock pad and call it good.

Noveski QD end plates are a little difficult to find. I bought mine from Freedom Fighter Tactical.  I mounted the QD side

of the end plate on the right side of the stock.  I think Todd from FFT are now making these plates themselves. They go for around $ 72.00

 

[StrangerDanger]

Nice work!

I think those Noveske plates used to go for around 25 dollars.

[HalG]

Ran across this as I was looking to change out my rear sling attachments.  Good stuff.  I made a small mod that might interest you guys. One of my M4's was a real PIA to get apart.  The pin was short threaded and the retainer plate was force threaded down.  I wound up having to red locktite a nut on the other end to get enough grip to break it loose.  Anyway I came up with this idea so I wouldn't have to mess with a recessed nut on the opposite end.  I put a slot in the end so it can be tightened up with a screwdriver during a reinstall.  I was able to get a good tight fit with a screwdriver.  If I reassemble with blue locktite the plate (278J) can simply be unscrewed after the locking nut is removed.  

My setup.  A bit of paper towel to hold the pin for insertion into the stock.  The screw slot from above.

[Freelancer99]

Just replaced my stock Sling Plate with the Noveske plate. Could not have been easier, thanks to SD and everyone who's contributed over the years. Encountered a lot of factory Loctite on both ends of the Stock Retaining Pin, the heat gun did the trick, don't use a torch of any kind as it will melt the nyloc portion of the Stock retaining Nut. The best tip was from HalG, definitely cut that screwdriver slot in the butt end of that pin, really speeds up reassembly, and a huge help if you ever need to get back in there! 

My only question for SD is regarding the spring washers. Can you add some detail describing the proper order that these should be installed. I assumed that they should go together to create four separate springs. Seemed to work pretty well.

Thanks again SD, all of your tutorials are really well done and really should be collected together and pinned for future reference.

[StrangerDanger]

Cool solution to adding the notch for a driver. That’s one of those things that Benelli should have developed into the part. 
 

You’re correct about the spring washer orientation. You build four compression springs when assembling them. So they look like this stacked:

 

( ) ( ) ( ) ( )

[benelliwerkes]

What SD said.

[Freelancer99]

Thanks Guys, 

Great update to an already excellent thread!

Note; thanks for pointing out the wear marks on your Stock Retaining bolt. On mine the threads were so beat up that I had to clean them up with an 8x1.00 die before reassembly. Maybe Benelli should cut a slot in the butt end, I sure made things easier for me!

Thanks again Guys