The "Adapter" Does Not Seem To Be The Problem.

[jackie schmidt]

I took a minute and used my Deltronic Pins to see if I could pick up any bore closer when I tightened my "adapter"onto the muzzle of the barrel.
A .2369 pin fits snug, a .2370 will not go in. I could just get the .2369 it to go in. I then screwed the adapter on, tightening a little at a time, seeing if I could still move the pin with the same force. I finally tightenned the thing as tight as I dare without stripping the 36 tpi in the aluminum.
The pin tightness never changed.
I know this is not the same as slugging, but I figure with my machinist skills, I could detect any change within .0001 that would occur. I couldn't.
So much for that..........jackie

 

[Vibe]

Thanks Jackie.

 

[Don]

I took a minute and used my Deltronic Pins to see if I could pick up any bore closer when I tightened my "adapter"onto the muzzle of the barrel.
A .2369 pin fits snug, a .2370 will not go in. I could just get the .2369 it to go in. I then screwed the adapter on, tightening a little at a time, seeing if I could still move the pin with the same force. I finally tightenned the thing as tight as I dare without stripping the 36 tpi in the aluminum.
The pin tightness never changed.
I know this is not the same as slugging, but I figure with my machinist skills, I could detect any change within .0001 that would occur. I couldn't.
So much for that..........jackie

From another posting;

Quote:
Originally Posted by JerrySharrett
A 0.0002" pin may not tell you the whole story.

Before I made the 6mm mold, I used to take pulled 22 rimfire bullets and squeexe them longways in a smooth-jaw vise till they were about 0.244-0.246" then use them to slug with.

I agree with Jerry, the deltronic pins, even in .0001 increments may not tell the whole story..............bullet to bore fit and pressure reaction at the muzzle may be more sensitive than .0001 increment fitups can account for relative to the tightening of the threaded adapter, and then there is the whole pressure expansion factor of the barrel at the adapter/barrel interface joint and the possiblity that the adapter reduces barrel expansion under pressurization due to added structural diameter.

But, I would still try the deltronic pins to see if any difference can be detected.............................Don

PS; If you do decide to bore slug the barrel at the adapter interface, an easier source than using Jerrys idea of .22 RF bullets for bore slugging is to use any lead cores that you might have left over from your bullet making days, bump them up very easily in the barrel since they are pure lead.