A 7 Round tube does NOT always fit 7 rounds in the M4

[nealc104 0]

For anyone else who couldn't find the answer to why a 7 round magazine tube on an M4, and probably the other products as well, couldn't fit 7 rounds -

I could not understand why my new M4 LE model with a 7 round tube would not hold 7 rounds of my Federal 00 Buck or Slug rounds - I checked for a limiter (which there shouldn't be one as it is a LE model, or any other blockage or obvious cause.  With a well-hidden reference on the internet about 2 3/4 inch shells being slightly different lengths, depending upon shot / manufacturer, I tried bird shot - and voila, I could fit 7 rounds.

What baffles me is that there is no information by Benelli about this fact, nor did CMC Government Supply, where I purchased the shotgun, offer this as a possible cause.  Perhaps I am the only one that did not know that some shells are a touch shorter...if there is one person, check out this "solution."  Of course it's not really a solution, as bird shot is not a tactical load (at least not in my book), and therefore to advertise a tactical shotgun as having a 7 round mag when you can't fit 7 tactical rounds, is deceptive. 

[Jolly Roger 22]

Thats because everybody is doing or has done a "mag cap modification"......after that, 7 rounds of any brand shell will fit in the tube.

[Jolly Roger 22]

........but of course,...Im just messing with you...welcome to the forum nealc104!  😀

[Evolution 22]

5 hours ago, nealc104 said:

For anyone else who couldn't find the answer to why a 7 round magazine tube on an M4, and probably the other products as well, couldn't fit 7 rounds -

I could not understand why my new M4 LE model with a 7 round tube would not hold 7 rounds of my Federal 00 Buck or Slug rounds - I checked for a limiter (which there shouldn't be one as it is a LE model, or any other blockage or obvious cause.  With a well-hidden reference on the internet about 2 3/4 inch shells being slightly different lengths, depending upon shot / manufacturer, I tried bird shot - and voila, I could fit 7 rounds.

What baffles me is that there is no information by Benelli about this fact, nor did CMC Government Supply, where I purchased the shotgun, offer this as a possible cause.  Perhaps I am the only one that did not know that some shells are a touch shorter...if there is one person, check out this "solution."  Of course it's not really a solution, as bird shot is not a tactical load (at least not in my book), and therefore to advertise a tactical shotgun as having a 7 round mag when you can't fit 7 tactical rounds, is deceptive. 

Birdshot? Iv'e never used anything but 00 buck and Federal slugs in my gun and it's always loaded 7 shells without any issue. Don't know what's going on there with your gun.

Let us know if you are able to resolve it.

[PremiumOctane 0]

I noticed a size difference between 2 3/4 brands. I had this one ammo "Law Enforcement" buckshot (I'm not even sure of the brand thats all it said) cycled fine, but couldn't hold 7... It appears the Federal Personal Defense ammo is longer than a lot of other rounds I have, I'm going to test this weekend if mine will hold 7.

[artES 10]

I had the same problem with an aftermarket +2 extension. Ended buying the orinigal mag extension from Benelliparts with a new spring and now I shoot 9 rounds of whatever I want from my M4

Edited February 19 by artES

[PremiumOctane 0]

13 hours ago, artES said:

I had the same problem with an aftermarket +2 extension. Ended buying the orinigal mag extension from Benelliparts with a new spring and now I shoot 9 rounds of whatever I want from my M4

Mine is a LE model, so it came from the factory with the +2 OEM extension.

[les_garten 11]

On 2/17/2019 at 8:35 PM, Jolly Roger said:

Thats because everybody is doing or has done a "mag cap modification"......after that, 7 rounds of any brand shell will fit in the tube.

I looked for that thread and can't find it.  

[Jolly Roger 22]

3 hours ago, les_garten said:

I looked for that thread and can't find it.  

..snicker...

[PremiumOctane 0]

7 of the Federal PD 2 3/4 fit in my Benelli LE M4 with the +2 extension on from the factory.

[nealc104 0]

Jolly Roger, thanks bud, lol.  I somehow have to threads going on this.  Just to be clear, it's a stock LE model that is supposed to hold 7 from the get go.  Don't want to mess up a $1700 piece of machinery.  I'm using LE rounds of slugs and 00 buck, but that shouldn't matter.  Also Winchester Super X slugs.  The mag should account for the size differences, or not advertise it as a 7 rounder.  Thanks again.

[DC DOG 14]

Hi OP:

Like you, I encountered the same problem after replacing the stock 5 round mag with a 7 round Freedom Fighter Tactical mag. It really is ammunition manufacture dependent, because not all shot shells are the same “exact” length. Even individual shells (by the same manufacturer) can vary. 

So, here’s how I fixed it (there is no “replacement” mag cap “modification” that I know of, BTW). There are essentially 2 springs for the Benelli, “long” and “short” (count the coils, don’t measure how long it is). The long spring takes up more room in the tube. The “short” spring (which comes with the 5 round) takes up less. I use the “short” spring.

Then, if you remove the srew-on mag cap, you will see a snap ring “cap” or “seat” (don’t remember the part name) that retains the mag spring in the tube. This “seat” is NOT indexed to the tube, meaning it can be seated deeply or at the very end of the tube and can be moved in or out. Using snap ring pliers, you can “back” this seat out some (it’s about 3/4 of an inch long). You DON’T need to back it out much, just enough so you see the end of it outside the tube (about 1/16 to 1/8 of an inch, if necessary). BE WARNED, backing it out too much will cause it to violently fly out of the end of the tube when you release compression, then you need to go looking for it (good luck with that, BTW). My seat is about 1/16 of an inch outside the tube.

Those two together “fixed” the 7 round “problem” for me. I use Hornaday “Critical Defense” 00-BUCK (2 3/4). Last thing - and this is also important - if you shoot your gun at the range, MAKE SURE you occasionally crank down on the mag cap until it clicks. The cap has a tendency to loosen when shooting many rounds. I’m not sure if the cap actually retains the end of the “seat,” but I don’t chance it. 

Hope this helps. Good luck!

[Jolly Roger 22]

Great post DC DOG! 

A few thoughts. Ive extended 4 m4's with the short tube by adding Freedom Fighter or Daves 7rd extension tubes. I had to go back and install Wolf springs to all of them because sooner or later they experienced failure to feed issues because the stock 5rd spring was to week. While adjusting the elevator down a bit seemed to be a temporary fix, installing the Wolf spring was the only real "cure". 

Adding anything aftermarket requires fine tuning and vigorous safety checks. (especially in the trigger mechanism) 

Moving the magazine spring retainer to its furthest outward position is a given when installing any spring, this insures the spring has full usage of the mag tube length. Aftermarket followers are another thing to keep in mind when trying to utilize the full potential of your tube. Oversize followers take away from your inner mag capacity. Many springs are tapered on the end because they were designed to fit inside the follower and not just rest behind it. This eliminates any sharp spring end from scraping the inner wall of your mag tube. Keep in mind when trimming a spring/fine tuning it, be sure to bend the cut inward with a pair of needle nose pliers. This goes for both ends of the spring, tapered or not.

When trying to fit 7 rnds into your new 7rnd tube, the differences in length per ammunition brands do vary. Dont let this train of thought limit your rnd cnt in your tube! I made that mistake. I found out that after installing the Wolf spring that 6 rnds of anything was the most I could squeeze into my tube, and I shot it that way for along time assuming it was just the brand or length of ammo. After realizing that the 7th rnd always was just about 5/8ths of an inch from going in the tube, a simple removal of 2 1/2 coils was the ultimate fix for me.

 

[les_garten 11]

I have the factory 7 round spring that came in my LE model.  I also have the spring that came with the carrierComp magazine.

Do I need to buy a Wolf spring? 

It would increase the impressiveness of my spring collection...

I am using the Facto 7 rd spring cause I figured it was factory and should be the best... 

[Jolly Roger 22]

You would be in the Wolf Spring club,....mine came with a whiskey decanter and shot glass.....

[L84Cabo 10]

Correct.  Not all 2 3/4" shells are the same size.  I've notice that the Federal LE Tactical w/Flight Control in the 9 pellet load is just ever so slightly longer than their 8 pellet load.  This makes a difference in my m4 as I can only get 6 rounds in instead of 7.  But it's not a problem in my Remington 870.  

My solution was to just use the 8 pellet rounds.  😎

[jimbo45 11]

I've always found the rio shells to be a bit longer than they should be.

[amccray70 0]

On 2/19/2019 at 3:50 PM, artES said:

I had the same problem with an aftermarket +2 extension. Ended buying the orinigal mag extension from Benelliparts with a new spring and now I shoot 9 rounds of whatever I want from my M4

I recently purchased an OEM 7-round magazine extension from Benelli parts and a new spring and it will only hold 6 rounds.

[Birdog19 18]

On 3/3/2019 at 12:47 PM, les_garten said:

I have the factory 7 round spring that came in my LE model.  I also have the spring that came with the Carrier Comp magazine.

Do I need to buy a Wolf spring? 

It would increase the impressiveness of my spring collection...

I am using the Facto 7 rd spring cause I figured it was factory and should be the best... 

Yup, you would be in the "Wolff Spring Club" as Carrier Comp's titanium mag tubes come with a wolff spring and a US made follower.

Follow the suggestions from DC and Jolly and DON'T be afraid to cut your spring a little shorter to gain full capacity.  As has been mentioned before on this forum, Benelli ships a spring meant for the full 7-round mag tube even though it also ships with the 5-round limiter mag tube, so straight out of the box it will be a little too long and may inhibit 5-round capacity with certain shells.

As for the mag tube seal ring, I don't have mine installed.  When I unscrew the mag tube nut the spring is not captured, but I know this and am ready to keep the spring from flying across the room.  Yes, safety glasses!

Trim your springs!

[sonyman74 8]

I once had a picture of 4 different 2-3/4" buck shot loads from different companies.  Depending on how it was crimped at the end the lengths were all different.  The difference in the longest to the shortest was a quarter of an inch.  I could only fit 6 in my mag of the longer brand.  The seventh round was about a half inch from going into the mag tube.  This was several years ago and I don't remember what loads it was exactly.