P-51 - Use of M3 .50 Cal Machine Guns on Post War Mustangs

[ronl]

Does anyone know if M3 .50 cal machine guns were used to any extent on post war P-51s? The M3 .50 cal had a recoil booster on the end of the barrel that lengthed the gun by about an inch, resulting in the barrel extending further out of the wing. The booster gave the end of the barrel a tapered look. Some ANG P-51 pictures appear to show longer barrels from the wings, and some seemed to use a special barrel cover that almost looked like a soup can over the gun muzzle. I have also seen some pictures of RCAF Mustangs that seem to show longer barrels.

I have seen a flight manual for the F-51 that had a diagram that makes reference to M-3 machine guns in the wings.

Any information would be appreciated. Thanks

Ron