[I'm so confused with mag extensions ... please help]

I just purchased a benelli m1 s90 riot gun for dirt cheap. Anyway, I would like to put a mag extension on it but here is where I'm going crazy. I would like the extension to be flush with the upper barrel.

 

Here is what the gun looks like now

 

 

I have not received this gun yet (still in DROS). But from the pic it looks like it has a 2 mag extension ... is this correct ?

 

So which mag extension do I need to make it flush ? Some vendors use different numbering scheme. For example, I can get a benelli 4 shot mag extension ... would this be the right one ? Or DMW has a 7 shot extension which I've been told is flush. But they also have an 8 shot extension which would probably extend the barrel. So would the benelli 4 shot extension extend the barrel as well.

 

Here is a reference to what has been said

 

http://www.benelliusa.com/forum/showthread.php?t=7417&page=2

 

Can someone please chime in here. Is this what I need (8 inch) ?

 

 

thanks

[To my fellow Benelli'ers & XD'ers!!!]

I love my XD45 ... just tried it out at the range. Thanks for the links

[Sure Fire M80 & M910a]

that's a nice looking benelli

[M4 Torture Test]

sweet thanks for the info

[Need you help. M1 S90 PG Stock dissasembly.]

that sucks ... good luck

[M-1/M-3 items forsale.]

Shucks ... I was just looking for the pistol grip as well.