so i got a benelli factory collapsible stock on my M4.  love the stock, but i want to add an additional stop on the recoil tube.  the mid stop is good for optics, but the irons are too low and the last stop is perfect for irons but the lop is too long.  anybody have the where to go to get it done?

This is why I just went with the urbino stock on mine.

Can you cut in more position notches? StrangerDanger would know more about this - Ask him

I seem to recall someone doing this to their M1014 clone yrs back.  It seems possible, the challenge being not butchering the tube in the process.  I've read the tube is secured with high strength Loctite, so a heat gun will be needed to release the bond, unless you want to attempt to do the work without removing it.

Modifying the 3 position receiver extension would be a much easier job than what we would have to do in the old days when we wanted to make the M1014/11703 models have a functioning collapsible stock. You would need a machinist that could plot the two grooves in relation together for it to function. The collapsible stock uses the button and a steel pin to lock it in position. When you press the button, it disengages one, and allows you to rotate the stock out of the fixed steel pin. If the machining isn't done properly, the lock will disengage while firing or the stock will be very difficult to engage into the notch.

You would need to remove the receiver extension from the M4 to have the work done. You'll need a MAPP torch to do this. It's not impossible, I have done many of them.

I also have some concerns about the durability of any machining done on the receiver extension. The existing extensions are heat treated around the machine points for the collapsible stock. You can see the discoloration in the stainless steel. Any new machining won't have this. 12 gauge recoil is pretty brutal on these small pins. In our slow motion tests, the entire M4 flexes quite a bit during the recoil impulse.

Given those issues, I personally would not do this work unless you had a shop that could properly heat treat already heat treated stainless. I certainly wouldn't take it to a hobbyist or a regular hack shop. I'd look into addressing a shorter LOP by maybe finding a Limbsaver Buttpad that is thinner that could be adapted to your firearm.

well, with that being said, maybe I'll just put my Urbino back on.  I'll save the C stock for when i want to look tacticool...thanks so much strangerdanger