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M4 Fore-end do's and don'ts


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Apologies if this has been covered before but I'm wondering if anyone has had any issues running aftermarket fore-end's and light/rail mounts. I have seen a number of posts but none specifically addressing what I experienced.

I recently broke the barrel guide ring on my M4 which was less than a year old and had less than 750 rounds in it. I was running a B&T fore-end with a CDM Gear rail mount (which happens to clamp to the barrel and mag tube). Benelli fixed the guide ring free of charge (minus $40 to ship it to them) but said I shouldn't run any aftermarket fore-end on it.

Has anyone else had any problems with the B&T rail? I'm thinking the culprit was more likely the CDM rail mount.

 

Many thanks.

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Can you post any pictures of the damage done, if you have any ?

Unfortunately I didn't get a picture but it basically sheared the weld right at the bottom of the barrel. It was my understanding that the Benelli gunsmith just re-welded it.

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The original weld on the Benelli might not have been sufficient. Companies like to blame aftermarket parts for problems. Sometimes it is true, sometimes it's just BS to cover for their own products failures. The only way I could see this happening is if the rail allowed for movement of the barrel during recoil. Eventually the barrel ring was hammered off.

 

Any odd wear around the magazine tube threads?

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These are pictures of what I was running on my M4 when I broke the barrel guide ring. I've pulled these off the web as I'm not running this config right now. The Benelli gunsmith mentioned that he thought the quad rail was preventing the barrel and mag tube from moving independently. I don't believe the fore-end would do this at all as it does not actually touch the barrel. The CDM mount (which I forgot to mention to the Benelli gunsmith) most definitely clamps the barrel and mag tube together which in my mind would explain the problem. I'm just trying to find out if anyone else is running the B&T fore-end without any issues as I'd really like to put that back on.

No damage on the mag tube that I see.

Thanks again for the responses.

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I wouldn't worry about the light clamp, they simply don't clamp that tight. And I don't think that is the issue anyway.

 

OP needs to check if the barrel ring is flush with the receiver. Not the ring around the mag tube, but the one back by the chamber. Early M1014s did not have this ring, and it was added for the sole purpose of visually checking to see if the barrel is fully seated in the receiver.

 

We have one well-known vendor who supplies forends that are a little long and the barrel will not fully seat. Upon firing the barrel (and mag tube ring) pushes back into receiver. If the barrel is not fully seated I am guessing that most of the stress is on the mag tube ring. Perhaps there is enough force to shear it off.

 

As stated OP needs to check if the barrel is seated, and that goes for the rest of us as well.

 

15417376109_76a1de577e_c.jpg

 

15580421106_51103124c5_o.jpg

Edited by BLACK
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attachment.php?attachmentid=2756&stc=1

Some barrels still come with or without the ring pictured above, i seen this recently with the 14'' M4 sbs barrels !

 

(Brügger & Thomet hand guard,Supernova collapsible stock with 5 position adjustment tube and factory muzzle brake)

attachment.php?attachmentid=2757&stc=1

RTG Parts is now carrying Brügger & Thomet parts for the Benelli.

http://www.robertrtg.com/store/pc/showsearchresults.asp?pageStyle=H&resultCnt=32&keyword=Benelli

Edited by heckler&kochp2000
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What about putting a new set of 11707 oem forend on older m1014s? I read a thread somewhere that earlier M4/M1014 forends wouldn`t be compatible on the newer 11707s, but in reverse new forends will fit on older M4/M1014. My 2003 M4S90 has no barrel ring, but does the barrel extension anyway seat properly against the receiver with new factory 11707 forends? By inspection through the ejection port I cannot see any gap between on my weapon, but can there be a little misfit that could rattle up the gun by time?

Edited by jaegerbataillon511
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Whoops should've looked a bit closer. I have the FFT handguards and they're just slightly too long on my gun.

 

Once again.......my apologies about that. They were used on my M4 for a few months until I got the FCG parts installed.

It looks as if manufacturing variances are to blame. They for some, but not all M4s.

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Once again.......my apologies about that. They were used on my M4 for a few months until I got the FCG parts installed.

It looks as if manufacturing variances are to blame. They for some, but not all M4s.

 

Nah no worries, I wanted to see if they would fit on my gun or not and they just happened to be slightly long. Definitely not sore over the trade, so hopefully I'm not giving that impression.

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Sorry for the delayed response.

Regarding the barrel clamp, I really had it cranked down after moved quite a bit the first few times I shot with it. Having said that, I had look at the point where the barrel joins the receiver. It does appear flush (as near as I can tell) but I realized that I may have another potential issue. I'm also running a Side Armor replacement top rail with removable shell carrier on the left side. It fits fine with the OEM hand guards but it's very tight where the shell carrier meets the left rail of the B&T forend. Pictures attached but wondering if it's worth filing that shell carrier down a millimeter or two.

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