Benelli M3 Super 90 - Mag extension?

[phaedra1106]

Anyone done this?

Not as straightforward as it would seem as the end of the tube is sealed and the thread that you'd normally attach the extension to is half way down the existing tube and retains the pump shuttle/foregrip.

Instead of replacing the entire mag tube I thought it may be possible to run a pipe cutter round the tube just in front of the threads and then fit an extension the same as you normally would?



Prposed cut point



Any thoughts?, just as we're off to the US I could pick up a tube quite cheaply

nb. This is a section 1 Fac version so no problems with extending it.

[saddler]

There'd be no problems anyway given the point on the main tube where the crimp is placed....ya muppet!

[phaedra1106]

It's not a crimp, it's a slight indent/channel for the barrel clamp to sit in so it doesn't move about

[saddler]

I woz do referring to the extending it....as in, you CAN so the same to a S.2 if ya so wanted - as the extension is in the dead-zone of the mag. tube

[Demonic69]

I wouldn't use a pipe cutter, the majority of them would cause the end of the tube to roll over a bit stopping the cartridges moving smoothly. A hacksaw in a simple jig would work better imho.

[phaedra1106]

Wonderful but can it be done??? has anyone done it?, I'm fairly sure someone said Dave at Valkyrie had extended one but I think that was by fitting a complete mag tube to a Sec.2.

Removing the existing tube out is not an easy job apparently and I can't see much in the way of a longer tube (mine is +7) so hacking it off and fitting the extension seems an easier/better way of doing it.

Demonic69, I thought a pipe cutter would give a squarer cut than me bodging about with a hacksaw, ideally I'd want to keep the existing spring. Best option would be to remove the tube and stick it in a lathe but as I said above, getting the existing tube off is not easy.

[Demonic69]

I can't see why not, your idea seems sound. As long as you can find an extension to fit your threads you're fine.
A pipe cutter would be nice and square but they tend to crimp the metal. If you made a jig first you'd take the chance out of using a hacksaw. An evolution chop saw would probably do well too, maybe even a dremel type tool and some patience.
You'd need to start with more metal after the threads and work back if your fore end is held on with those threads.

[phaedra1106]

Indeed, about 1/4" after the threads should do it.

I tried screwing the locking collar onto my Super Nova mag tube when I had it and the threads were the same so one of those extensions should fit

[Demonic69]

The other option would be to cut off the very end of the tube and have a press-fit collar and extension, probably held by barrel clamps. A bit more difficult unless you have access to a lathe

[phaedra1106]

Yes, I could cut it off where the existing barrel clamp sits then use it to hold the tube in place. A capped tube of the same inner and outer diameters with a sleeve over the joint would do nicely if clamped at the joint and further along the extended tube