Anyone tried cutting a chunk out of the square rail (has the 6 holes in it that index with the butt stock) that is made into the bottom of our "Buffer Tube" so that a standard AR15 QD sling attachment can be mounted next to the back of the receiver?

It would be easy to cut but the obvious caveat is will the buffer tube then be strong enough for normal civilian use. I think it would be but there is no going back and the tube breaking off of the most valuable part of the rifle is not to cool considering it would not be warrantied.

Now I know what many will say, don't cut just use this:


Well I have that and it is not satisfactory for 2 reasons.
1. Main deal breaker: Not limited rotation socket. What ever I mount must be limited.
2. Actual clamping surface touching tube is only about 1/8" because it was never designed to clamp on a tube but on a castle nut which we obviously don't have.

The one I want to use is this:


It has a much stronger design and larger clamping surface designed to clamp on the tube not the castle nut and it has 3 sockets with limited rotation.

I can easily remove the large projection on it that fits under the castle nut but it does not have a channel made into it for the "square rail" since a "real" AR's buffer tube rail does not run all the way to the threads.

I can machine a channel in it but then it will not have enough material left for strength plus there won't be anything left of the center QD socket which is the one I want to use.

Cutting a 5/8" chunk out of our 'square rail" next to the end of the receiver will allow this MCTAR30HD mount to fit.

To me a simpler option is to upgrade the stock to a Magpul CTR or similar, that has a built in ambi QD mount.

You get a much better stock plus QD all in one. If you go with the STR, you get a storage compartment too.

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FIDELITAS ET FORTITUDO

Thanks for the reply Jim.
I should have been more specific in my post.
I will be using a 1pt/2pt convertible sling kind of like a Magpul MS4. I will use it in both modes depending on what I'm doing.

When using a 1pt sling I feel the mounting point should be at the back of the receiver to keep the rifle high on your body and it helps keep the sling out of the way during transitions vs a butt stock mount.

In 2pt mode the rear of the sling can be attached at the butt stock or at the rear of the receiver but here again the receiver mounting point keeps the rifle higher on your body and sling out of the way.

Be aware I am not talking about the old traditional "carry strap" sling mounting that attaches at the rear bottom of the stock and at the front bottom of the hand guard like a hunting rifle or a stock M16A1. When referring to 2pt I mean the modern style where both of the attachment points are on the side of the rifle which keeps it laying flat against your chest

I don't know how much experience everyone has had using slings equipped with QD swivel mounts but the sockets on the weapon must be limited rotation, meaning the mount can only swivel approx 90 degrees. If they swivel 360 degrees the sling will wrap it's self up when transitioning or mounting/demounting on your body. Then you have to stop and untwist it. Limited rotation solves this.

Most people making sockets have switched to limited on their latest versions because they have wised up but some of their older products have not been redesigned. Magpul is one of the worst offenders when it comes to not updating sockets. 99% of their stocks and forearm mounts still are 360 rotation. IWC makes a lot of $ selling a bolt on limited socket to fit Magpul stocks, in fact it is their 6th best selling item.

I have tried all of the various mounting positions and for me the best spot is at the front and rear of the receiver. Yes this means the distance between the mounts is only 9" but it works like a champ. If I want to use the sling to help brace the rifle during long range shooting I move the front of the sling to another socket at the front side of the hand guard.

I have a CTR on it now. I can't use it for connecting a sling for my use since the sockets on it are not limited and as stated above I want a rear receiver mounting position.

So I am back to possibly cutting a chunk because no one I can find makes a full surface clamp on mount with limited rotation.
With the number of 15-22's out there maybe someone will eventually market one for it but in the meantime it may be hack saw city with a touch of Dremel.

Just wish I knew how much a 5/8" chunk of rail missing where the buffer tube meets the receiver would weaken the stability of the tube. I wouldn't even worry if the chunk was taken out of the middle or back of the tube but right where it joins the receiver may be a different story. On the other hand the tube could very well be strong enough by it's self.

Here is an informative video showing the modern tactical sling carry positions and testing one of the finest slings money can buy:

http://www.youtube.com/watch?v=Ny5b7VXUU78