Surefire M80 Issue

[jyp1911]

I just bought a new Surefire M80 rail for my Benelli M4 and I have the same gap between the barrel collar and receiver that other people have had once the rail is installed. The barrel is not fully seated inside the receiver so this can't be right or good. I thought Surefire had fixed this problem which is why I bought the rail. I have seen this rail being used by other people on the internet so do they just live with the gap and run their guns like that or do I have a defective rail? I emailed Surefire Tech Support and am waiting for an answer but I wanted some unbiased opinions. I have read the other threads reguarding this problem but does anyone have any other info?

[Hookster]

Hi jyp

 

Check out post #41 of this thread. (also #s 23 & 35)

 

http://www.benelliusa.com/forum/showthread.php?t=19590&highlight=kz+review&page=5

 

 

It turned out the problem was with a slight distortion on a OEM part.

 

My M80 has no fit issues

 

Later,

 

Hookster

Edited October 5, 2010 by Hookster
added info

[jyp1911]

Thanks for the help Hookster. I didn't even think about the problem being with the OEM magazine tube barrel bracket and not the handguard. I guess the specs on the magazine tube bracket under the barrel varies since some people say they have fitting issues and some don't. Benelli probably doesn't see it as a problem since the factory handguards are unaffected by this slight size variation since they push against the spring washers inside the bracket and not the bracket itself. I bet most people don't always notice when the barrel isn't fully seated since it is such a small gap. The only reason I noticed is because the receiver area below the feedramp started to get worn and damaged from the shells hitting it instead of the feedramp. This only started happening after I installed the Surefire rail so upon closer inspection, I realized the barrel wasn't fully seated.

 

I need the Surefire rail for 922r compliance with my US made full length magazine tube and US made follower, so I took a file to the face of the under barrel magazine tube bracket. I slowly removed material from the face of the bracket constantly checking the fit to be sure I wouldn't remove too much and end up with a loose fitting Surefire rail. In the end, I probably removed about 1/32" of material and the barrel is now fully seated with the Surefire rail installed. I finished the bare steel with some cold blue and with the rail installed you can't even tell I filed the bracket. The factory handguards also still fit fine after all the filing.

 

To the people looking to install a Surefire or other rail system, I'm going to guess that if your Benelli M4 has about a 1/16" gap between the handguard lip and under barrel magazine tube bracket, at the bottom, then you shouldn't have any problems with installing a rail system. However, if the bottom hanguard lip edge is almost right up against the face of the under barrel magazine tube bracket, then you will probably need to do some filing to get a proper fit. If anyone with a Benelli M4 that didn't require modification to install their rail could confirm this by checking the gap between the factory handguards and face of the under barrel magazine tube bracket, let me know what you find.

Edited October 7, 2010 by jyp1911

[Hookster]

Hey JYP,

 

I'm glad all worked out well

 

Later,

 

Hookster

[ROCKETW19]

Thanks for the help Hookster. I didn't even think about the problem being with the OEM magazine tube barrel bracket and not the handguard. I guess the specs on the magazine tube bracket under the barrel varies since some people say they have fitting issues and some don't. Benelli probably doesn't see it as a problem since the factory handguards are unaffected by this slight size variation since they push against the spring washers inside the bracket and not the bracket itself. I bet most people don't always notice when the barrel isn't fully seated since it is such a small gap. The only reason I noticed is because the receiver area below the feedramp started to get worn and damaged from the shells hitting it instead of the feedramp. This only started happening after I installed the Surefire rail so upon closer inspection, I realized the barrel wasn't fully seated.

 

I need the Surefire rail for 922r compliance with my US made full length magazine tube and US made follower, so I took a file to the face of the under barrel magazine tube bracket. I slowly removed material from the face of the bracket constantly checking the fit to be sure I wouldn't remove too much and end up with a loose fitting Surefire rail. In the end, I probably removed about 1/32" of material and the barrel is now fully seated with the Surefire rail installed. I finished the bare steel with some cold blue and with the rail installed you can't even tell I filed the bracket. The factory handguards also still fit fine after all the filing.

 

To the people looking to install a Surefire or other rail system, I'm going to guess that if your Benelli M4 has about a 1/16" gap between the handguard lip and under barrel magazine tube bracket, at the bottom, then you shouldn't have any problems with installing a rail system. However, if the bottom hanguard lip edge is almost right up against the face of the under barrel magazine tube bracket, then you will probably need to do some filing to get a proper fit. If anyone with a Benelli M4 that didn't require modification to install their rail could confirm this by checking the gap between the factory handguards and face of the under barrel magazine tube bracket, let me know what you find.

Can you post a picture of what you are talking about and where you trimmed it please? I wish you would of did a before and after but oh well a after is good.

[AggiePhil]

Can you post a picture of what you are talking about and where you trimmed it please? I wish you would of did a before and after but oh well a after is good.

 

Bump to the top for photos. This is a case where a picture would be worth a thousand words.

[Flascot007]

I know on my surefire fore grip, I had to remove about a 1/16" notch where the back of the fore grip seats against the stop ring on the barrel near the chamber. The grip would flare over the top of the ring and then not fit tightly against the barrel. so a sharp razor and some small cuts to notch the new fore grip until it seated without wanting to flare out around the barrel stop ring.