Help identifying M11/9

[icguns]

Someone suggested I ask here for details about this m11 reciever so here goes:

The reciever on the top has a trapezoid mag well and accepts zytel mags.

The reciever on the bottom has a rectangular mag well and does not take zytel mags, they won't fit more than half way in the grip frame.

The receiver on the bottom will accept an uzi mag with some degree of slop front to back, and a STEN mag up to the point that the ears on the mag contact the bottom of the magwell and go no further. Neither one seems correct- unless I'm to smash the ears flat on the sten mag to get it to fit?

My question: what mag should the bottom receiver take? It is not a machinegun but was bundled with a colossal box of mac parts I bought. Before I trash a sten mag just to see what happens is that right? Does a M11/9 bolt feed both zytel and sten or uzi mags without modification?

If I was to guess I'd say it's supposed to be a sten. But I'm not sure.

The reciever is marked COBRAY RKW, and I think it was made in '94. Judging by the SN.

 

[Deerhurst]

Paging MitchWerbellsGhost! I'd be willing to bet you know what's up with this!

I was under the impression the M11/9 only had the Zytel magwell.

Possible M10/9 magwell grafted on?

 

[chili17]

look like STEn

 

[icguns]

Paging MitchWerbellsGhost! I'd be willing to bet you know what's up with this!

I was under the impression the M11/9 only had the Zytel magwell.

Possible M10/9 magwell grafted on?

The lower is new unassembled. It sure could be grafted on, but it looks pretty good.

Are these as rare as it seems?

 

[Hey...]

I agree probably STEN. Used to be a popular mod but typically for SMGs. Post a pic from the side

 

[root]

How many sten mags ya got to try?

I ask because sten mag specs are all over the place some will fit and run some will fit and not run and as you see some won't even fit.

Common thing for mass produced surplus mags.

 

[hkg3k]

My question: what mag should the bottom receiver take?

The grip-well on the bottom M11/9 is exclusively for a STEN mag. There were a couple different STEN grip-wells made for the M11/9 back in the day (AWB days). The one on your gun was made by Craig Wheatley, prior to him starting Tactical Innovations.

HTH

 

[icguns]

I agree probably STEN. Used to be a popular mod but typically for SMGs. Post a pic from the side

Here are some more pics

As you can see, even for the sten mag, it won't fit in the grip unless I am to remove or flatten the side tabs on the mag.

How many sten mags do i have? I think around 15 right here. Also have a FA sten so I don't want to destroy these mags - as they do run.

I got this with a bunch of other mac parts, accessories, smg parts, optic rails, as well as two MGs a m11/9 and M10a1. There are seven lowers of different vintage and detail. This one was the only one I had questions about.

 

[icguns]

The grip-well on the bottom M11/9 is exclusively for a STEN mag. There were a couple different STEN grip-wells made for the M11/9 back in the day (AWB days). The one on your gun was made by Craig Wheatley, prior to him starting Tactical Innovations.

HTH

Is this a rare piece? Not needing all these parts I may sell some. What's this one in particular worth?

 

[hkg3k]

As you can see, even for the sten mag, it won't fit in the grip unless I am to remove or flatten the side tabs on the mag.

Yep, you'll need to file the tabs (or lightly tap them in with a hammer) slightly so the mag will enter the grip-well and engage the internal stops. Doing so won't preclude them from still being used on your STEN smg.

Is this a rare piece? Not needing all these parts I may sell some. What's this one in particular worth?

Not really. They're a product of the 94 AWB when Zytel mag prices went over $200 each -and- didn't last long due to feed lip erosion with F/A use. At the time, STEN mags were still dirt cheap and Craig Wheatley introduced a way to utilize a cheap high cap mag for the M11/9 when high cap mag prices were insane. Today (with Z-mag availability), most view the STEN conversion as a negative. I don't necessarily agree with that sentiment as I have 2 F/A guns with the STEN magwells...and they've always been extremely reliable. They also accept the 50rd Lanchester mags as well.

There was another STEN grip-well for the M11/9 that came later...one which looks in profile like the Grease Gun grip-well on the M10-45, where the tab channels for the magazine can be seen on the outside.

 

[icguns]

Yep, you'll need to file the tabs (or lightly tap them in with a hammer) slightly so the mag will enter the grip-well and engage the internal stops. Doing so won't preclude them from still being used on your STEN smg.



Not really. They're a product of the 94 AWB when Zytel mag prices went over $200 each -and- didn't last long due to feed lip erosion with F/A use. At the time, STEN mags were still dirt cheap and Craig Wheatley introduced a way to utilize a cheap high cap mag for the M11/9 when high cap mag prices were insane. Today (with Z-mag availability), most view the STEN conversion as a negative. I don't necessarily agree with that sentiment as I have 2 F/A guns with the STEN magwells...and they've always been extremely reliable. They also accept the 50rd Lanchester mags as well.

There was another STEN grip-well for the M11/9 that came later...one which looks in profile like the Grease Gun grip-well on the M10-45, where the tab channels for the magazine can be seen on the outside.

With all this great info I will see if I got enough parts here to build the sten lower up and see if it functions.

I didn't realize that the sten mags could work in a sten without the tabs, as I figured they set the depth inside the reciever tube. So sacrificing one for this test seems reasonable considering it would still work in the sten.

Does the cobray bolt natively work with the sten mags? I am curious what keeps the sten mag from over feeding into the reciever?

 

[hkg3k]

I didn't realize that the sten mags could work in a sten without the tabs,

That's not what I wrote. To clarify, just file to remove (or tap in slightly) enough of the tab so they enter the grip-well...there'll still be enough tab left to do their intended job on the STEN magwell.

Does the cobray bolt natively work with the sten mags? I am curious what keeps the sten mag from over feeding into the reciever?

Yes, the bolt works fine with the STEN mags as it's just another single position feed magazine. The STEN mag is not the only existing mag to be successfully adapted to the M11/9 (Madsen & PAM mags come to mind). It's the mag tabs engaging the internal stops of the grip-well that prevents the mag from being over-inserted. So even with the grip-well, you still need those tabs on the mags.

 

[icguns]

That's not what I wrote. To clarify, just file to remove (or tap in slightly) enough of the tab so they enter the grip-well...there'll still be enough tab left to do their intended job on the STEN magwell.



Yes, the bolt works fine with the STEN mags as it's just another single position feed magazine. The STEN mag is not the only existing mag to be successfully adapted to the M11/9 (Madsen & PAM mags come to mind). It's the mag tabs engaging the internal stops of the grip-well that prevents the mag from being over-inserted. So even with the grip-well, you still need those tabs on the mags.

Awesome, and I see what you mean on all accounts.

First I tapped the dimples inward closing them about half way. Then it would fit in the grip.

There is a step shoulder on the inside I didn't notice before, the mag rests nicely against that to set the depth.

And, like you said, it still works in the STEN.

So I suppose I have to add a small strip of steel to the back of the mag in order to catch the mag release on the M11. That should be easy with a little tack weld.

I fed a bunch of snap caps easily by holding the mag in place. I think I got enough parts to throw this together tomorrow, will definitely try!

 

[hkg3k]

So I suppose I have to add a small strip of steel to the back of the mag in order to catch the mag release on the M11. That should be easy with a little tack weld.

Nope. Not necessary and not the way it works. The mag catch on the STEN grip-well sits higher than on a regular grip-well. This is so a stock mag catch can engage the rear of the STEN mag without the need to add a separate engagement strip. What you will have to do is cut out / channel the rear of the plastic grip to allow for the re-positioned mag catch.

Attached is a pic that hopefully illustrates that...and something you'll definitely see when you add the mag catch and rear grip on the grip-well.

 

[root]

15 mags?

Yer gonna need more for sure.

Glad it got figured out with what needed done.

Who ever mentioned sten mags were cheap in the 90's wasn't kidding.
CDNN & Centerfire used to use them for packing orders.
I got over a dozen sten mags as packing material back then with different orders.
Even called to ask why and was told used to take up space.

I would not consider a sten convefsion on anything a waste or detractor.
I'd look at it as a plus.
Sten mags are still cheap.

 

[MAC MAN]

RKW lower is Russell Kenneth Weeks. The newer RPB in Avondale Estates Ga. Russell Parts Bin. The Mac Man book page 447 and 470.

 

[MitchWerbellsGhost87]

RKW lower is Russell Kenneth Weeks. The newer RPB in Avondale Estates Ga. Russell Parts Bin. The Mac Man book page 447 and 470.

Yep^^ beat me to it. These are somewhat rare lowers. I think they were from 1994 if my memory serves me correctly. RKW stamped, all of them have sten magwells as far as I know. As others have mentioned, the mag catch situation with an M11/9 sten mag model can be a little bit of a pain in the ass.

 

[MitchWerbellsGhost87]

15 mags?

Yer gonna need more for sure.

Glad it got figured out with what needed done.

Who ever mentioned sten mags were cheap in the 90's wasn't kidding.
CDNN & Centerfire used to use them for packing orders.
I got over a dozen sten mags as packing material back then with different orders.
Even called to ask why and was told used to take up space.

I would not consider a sten convefsion on anything a waste or detractor.
I'd look at it as a plus.
Sten mags are still cheap.

Wouldn’t it be cheaper to just use packing peanuts, or scrap paper or something? No matter how I try to envision it, I cannot think of any scenario where using perfectly good sten magazines in place of shipping material would be a money saver. Even if I had 50 pallets of them.

 

[MAC MAN]

I think FTF sells a Sten magazine catch for the M-11/9mm.

 

[Gaujo]

The detailed replies you've gotten on this thread are remarkable. We're very lucky to have such knowledgeable and generous members.

If this was ar15.com you would have gotten an answer with six acronyms nobody knows what they mean or a snarky response that you should already know it.