Any tricks to installing a Benelli M2 mag extension (help)

[kagetsu]

I'm trying to install a Benelli +4 magazine extension on my M2 Tactical.

I cannot get the 36" spring compressed into the tube without the center twisting out sideways. Many more tries is sure to damage the spring. What can I do? Short of seeing if the local gun shop can do what I can't.

[Tuflehundon]

Did you trim the spring to fit? The extensions all ship with the same spring, no matter is they are a +1 or a +8. You have to trim the spring to fit. It should be between 12" & 16" longer than the tube and extension when not under pressure. It's trial and error to see what works. Mine is 13"s longer and that works perfect for me.

[Creeper]

It should be between 12" & 16" longer than the tube and extension when not under pressure.

 

Yep... start at about 16-18 inches, see how the gun functions, how much effort is required to load and that it takes all the shells it's rated for. If it's really stiff to get those last rounds in or doesn't take full capacity, take an inch or two (or three) off.

I've never gone below 14" on a 8 round tube 3-gun M2, but I know a few guys that have experimented with springs as short as 10" of free length on 9 and 10 round tubes... didn't work too well for feeding the last few rounds, but man, it sure was easy to load!

[kagetsu]

I'm afraid it is now too short. I knew I'd screw up.

[truckcop]

What makes you think it's too short? And if it is, big deal. Buy a 3-pack of Wolff springs from Brownell's. Cheap.