76/760 Barrel Interface Experiments – part 3

[Jim in Texas]

My first two sets of experiments did not require any modifications to either the barrel or receiver.  I have been unable to come up with a way to mechanically index the barrel to the receiver without modifying both of those components.  

Before I start modifying expensive parts, I thought it might be prudent to make a dummy receiver nose and barrel stub.  I can then conduct my experiments on those more-disposable components.  

In making the dummy receiver nose, I omitted the threads for the barrel nut and instead turned the outside diameter of the nose to the minor diameter of those threads (approximately 0.914”).  That way, it will be easier to see if any of my experiments accidentally break through the outside wall of the receiver nose.

In making the dummy barrel stub, I made it double-ended so I could double the number of experiments I could conduct on that one part.

Here are photos of:

1.  the dummy receiver nose next to a barrel;

2.  the dummy receiver nose with the barrel inserted; and

3.  the dummy barrel stub next to the dummy receiver nose.

Now that I have some low-risk models, I can start trying out different ideas for mechanically indexing the barrel to the receiver.  If you have any suggestions, please share.

 

[Rekraps]

Hey Jim, as always I really like to read your posts. I was watching a YouTube segment posted by a guy named Andy (It's Andy's car repair) and this guy is a very excellent mechanic, with people coming to him from all over the US to have their vehicles repaired. 

One segment he posted gave me an idea. On the Ford PowerStroke Diesels, the main timing gear is pinned to the crankshaft and of course the pin shears off. His solution, and the one that Ford used for many years (until they saved $0.01 per vehicle by pinning the gear) is to "key" the part. I think that would work perfectly with the 76, but require a permanent modification to the trunnion. You would weld a nice raised "key" to the barrel neck and then machine a matching recess into the trunnion. Similar to the "K" gun. The barrel would then be fixed.

Now, as I have said before, for what I use the gun for, and based on the original specs and use of the gun, the OEM configuration is suitable for combat and everyday shooting.