RE: [G104] Worn paint on collar of M1A1 76mm barrels
On gun tubes there is typically a cylindrical section near the breech that guides the tube during recoil. This cylinder is machined to very close tolerances and a fine finish. Normally it is not painted because paint would only be worn off in use, if it did not interfere with the functioning. On the M62 mount and M1 series guns this cylinder protruded about one diameter beyond the gun shield, and from there the tube tapered down to the muzzle. So, the length or the cylinder varied depending on the tolerances on the diameter and slope of the taper.
Polished bare steel often looks dark gray and in B&W photos I think it would be hard to distinguish. Also, for camouflage purposes, a special dyed grease was issued to cover these sorts of surfaces to reduce their reflectance. With that grease applied it would look painted and probably pick up the same dust coating as the rest of the tube.
The diameter of the gun shield had a large clearance right at the end of the collar but it was tighter farther in, as well as in the mount itself.
Can anyone comment on the phenomenon where a 5-6 inch section of paint was worn on the 76mm barrels of T-23 turrets? It would occur at the base of the barrel where it enters the mantlet -- supposedly from being worn off due the recoil action of the gun tube. I've seen photos that seemingly support this as well as other 76mm armed Shermans that seem to have the paint intact. Why the inconsistency? Or was this paint wear universal and I'm misinterpreting the photos that seem to show intact olive drab all down the length of the barrel?
If it did occur occasionally, was it only on certain factories'' parts?
Also, when it did occur, was the wear caused by the tube wearing on somewhere on the tube carriage internal to the mantlet? It always seems that the actual collar mantlet has clearance.
Thanks in advance.