105mm

Gist inspector, Mrs. Mary Betchner inspecting one of the 25 cutters for burrs before inserting it in the inside of a 105mm. howitzer at the Milwaukee, Wis. plant of the Chain Belt Co. Her son is in the army; her husband is in war work (LOC)

from The Library of Congress

• dooooooowop said:

  She doesn't look a day older than 25.

• maniacal run said:

  Something about that caption doesn't quite ring true. The dimensions and near-center mount are consistent with the *barrel* of an M2A1 or M101 howitzer. Note that the left end is turned down, which is characteristic of the breach end of the weapon. She's using a micrometer to check a boss or flange of the outer diameter near the center mounting point, which is already greater than the roughly 4" ID of the barrel. No "cutters" are evident, so there's no way one could be inserted *into* the barrel. The castellated sleeve is probably internally threaded and engages the external threads seen on the barrel directly behind her.

• smooth stomach said:

  inspector23, Photographers are not engineers.

• Brant Dempster said:

  I've found in military history research that many anomalies and aberrations occur between the photograph and the caption. "Kurtz" said it best - "Photographers are not engineers".