Miami_M4

STA - The gas pistons as well as the rest of the gun is fine. Look, the situation is as we have all come to see, 4-Port "Low Recoil Rounds" barrels are for that type of ammo ONLY, no matter what Benelli says or states in thier manual. It's just a shame that we have to do this type of research ourselves! I would love to get a 2-Port barrel for my M4 11707, but we will have to see what Benelli Customer Service does with my repair. And after reading some other threads, I do not think that is going to happen. Maybe a letter from an Attorney might help...hmmm

My friend is selling his M4 11707 w/ Side Saddle and 2 Shot Extension. Less than 300 rounds thru it. It has the "Low Recoil Rounds" barrel" as well. PM me and I will give you his info, if you want to get the details.

I shoot a lot of 3-Gun Matches with heavy steel poppers, and paper targets out to 30 yards. I know "Tactical" ammo is available, but cost can be an issue for general "plinking". I need suggestions on what Brands of Low Recoil Ammo that works and will not "batter" these 4-Port Barrels: #6 Shot "Low Recoil"? Slug "Low Recoil"? 00 Buck "Low Recoil"? Your feedback would be helpfull, so I do not "Break" my bolt carrier or gas pistons.

Thanks for all the feedback, and I am beginning to see what I am going to have to do. For all of us that have 4-Port "Low Recoil Rounds" Barrels on our M4's, we are going to be limited to just that, Low Recoil Rounds. I am just starting to work with Customer Service, since they are short staffed this week. I will keep you posted on what I find out.

Well, it happened to me again! My M4 11707 LE broke over the weekend and this time it is in a different spot. I have less than 350 rounds thru it since I got it back after Benelli replaced the bolt carrier and barrel when it broke the first time. During a routine cleaning and inspection after the shoot, I noticed that the bolt carrier had cracked. The crack is on the left side of the bolt carrier and is just below the bolt head pin cam channel. See Photos: Benelli M4 Cracked Bolt Carrier Pictures I use Remington Game Load #6 2 ¾ inch shells exclusively for the 3-Gun matches I shoot in, and occasionally Remington Slugger Slugs for paper targets in certain stages. It is equipped with the 4-Port “Low Recoil Rounds” barrel that has been the subject of recent threads on this board. After reading a thread “M4 Barrel Markings” posted by STA on 6-11-2005, and analysis by STA and others, I am beginning to believe that you CANNOT shoot “standard load” 2 ¾ shells or 3” shells in a M4 equipped with a 4-Port “Low Recoil Round” barrel. If you do, it will cause “battering” of the gas pistons, and bolt carrier, which in turn will lead to failure. But, if you read the “M4 SUPER 90” Manual (G0093602 – 01/2003) it states on page 72, “Choice of Ammunition” - “The M4 can use 12ga. Shells with 70mm (2” ¾) or 76mm (3”) cases.” So, now what do we do? I certainly do not want to be limited to “low recoil” rounds in my super duper, hardcore, military approved M4! And, for those of you who will say; “if it breaks Benelli will buy me a new one”, what do we tell the family members of the person who was relying on an M4 as a home defense gun, and it broke during an incident that cost them their lives?

Guess What? Another M4 LE / 11707 with Serial # Y0074xx suffered a catastrophic failure during an IDPA 3 Gun Match! The failure was exactly the same type that I had, but much worse! During a buckshot stage, the shooter was firing OO Buckshot when the bolt “froze” while it was trying to eject the spent shell, immediately rendering the shotgun useless. The failure was so severe that the bolt remains “frozen” just about a ½ inch back from the “closed locked” position with the spent shell still attached by the extractor. Again, the cause of this failure is a failure of the metal rail on the left side of the bolt carrier. The metal is just too soft! The gas piston actually “punched” out a piece of the bolt carrier and wedged it between the receiver and the bolt! We can see this by looking through the gap between the spent shell and receiver. I whish we could get a picture of this, but it is in such a tight place that only a fiber optic camera could do the shot. I am telling all of you M4 LE / 11707 owners, that there is a serious problem with these bolts, and if you have not fired at least 200 rounds of “Bird” and 50 rounds of “Slugs” then you’re just asking for trouble at the wrong time. Again, the serial # of both guns that failed are in the range of Y0074xx, if you own one near these I would check them out, and do it soon!

To answer your questions regarding the rest of the ARGO System on my M4: Gas Pistons: They look fine, and travel smoothly in their tubes. Gas Piston Stops in the Reciever: No damage or signs of overtravel impacts Reciever Rails: Again no damage or signs of "excessive" wear. That is why I think the issue is related to the manufacture of the bolt carrier. I sent the whole gun back, at thier request. They felt that due to product liability issues, a simple replacement of the bolt carrier would be risky. That indicates to me that there may be "other" issues with the M4s that we do not know about, and they want to see if this one has any of the "other" issues. I requested a complete replacement, just for "peace of mind", since this too is not a range weapon, but my home defense weapon.

Here is the detailed summary of the failure with supporting pictures and documentation. The link is to a PDF file: M4 LE 11707 Failure Summary

I purchased my M4 LE / 11707 on October 6th 2004 under the impression that the Benelli M4 LE / 11707 is the most reliable, heavily tested and respected tactical shotgun on the market. I was willing to pay the premium associated with owning a Benelli and did. I am very disappointed with product I had purchased since it “broke” after less than 200 rounds! Background History: October 6th 2004 – Purchased New in Box at an Authorized Dealer October 7th 2004 – Lubed and Assembled for Shooting October 9th 2004 – Went to the Range and fired: (75) Rounds Winchester SuperX Game Loads, 12GA, 2 ¾, 3 ¼ DR EQ, 1 OZ, #7½ Lead Shot (25) Rounds Remington Game Load, 12GA, 2 ¾ , 3 ¼ DR EQ, 1 OZ, #6 Shot (10) Rounds Remington Slugger High Velocity, 12GA, 2 ¾ , 1800 FPS, 7/8 OZ Slug Note* Fired all rounds with out any malfunctions October 26th 2004 – Tactical Shotgun Class Was able to fire the following prior to failure: (10) Rounds Remington Slugger High Velocity, 12GA, 2 ¾ , 1800 FPS, 7/8 OZ Slug (15) Rounds Winchester SuperX Game Loads, 12GA, 2 ¾, 3 ¼ DR EQ, 1 OZ, #7½ Lead Shot Note* I fired the (10) rounds of Slugs in the first half of the class for sighting in purposes with out any malfunctions. I then began to fire the Winchester SuperX Game Loads in various drills we were doing when after (12) rounds the bolt began to “lock” back after each shot. I would try to use the bolt release, but that would not release the bolt. I had to actually “push” the bolt forward to close it. I did this (3) times, at which point I felt that it was unsafe to continue the class. October 26th 2004 – Field Stripped and inspected why the shotgun malfunctioned. I found that the Gas Piston on the left side of the barrel had impacted the Bolt Carrier with enough force to cause an indentation in the Bolt Carriers metal rail. This indentation then caused the rail on the bolt carrier to swell enough to prevent smooth operation in the receivers’ rail grooves. After further inspection, the right side rail has some indentation, with a slight deformation of the metal. Summary: I was not and do not use reloads in any of my shotguns! “Standard, Off the Self” Remington Slugs and Winchester Bird Shot do not contain any “super powerful” charges that would cause this type of damage. It appears that the metal on the rails of this bolt carrier is “too soft”! I am very disappointed with quality of the product I paid “good money” for. It is also embarrassing for you as well when your newest product “breaks” in front of a class of 24 law enforcement professionals who were all in awe of the Benelli M4. The comments after the class, were “I will stick with my 870!” Not good! I am in the process of dealing with customer service, so I will keep you all posted. I have detailed pictures of the bolt carrier and would like to post them but could not figure it out. So, let me know how to post images or I can post the PDF of the document I prepared for Benelli Warranty Service that includes detailed pictures and explanations.