Heat stamp

[clllclal]

My M1 has a heat stamp of M 340 A. Anyway to know what date range this falls in? Ive checked through other posts but couldnt find anything. Also, were Vietnam era liners maker marked. Mine just has an X in the crown. Thanks for your help.

[Theriddler]

Hi

M340A indicates that you have McCord shell manufactured during the early 50’s. Do you have a picture of your liner? Does it have stitching going around the inside of the liner shell? I have a similar liner from the Vietnam period with just an X and no manufactures markings. Research indicates that the X represents a liner made from a lease loan mold also the style of markings stamped on the interior webbing will give you a date of manufacture and may possibly help to identify the marker of the liner.

[clllclal]

Yes, it does have stitching going around the inside of the liner. Thanks for the information.

[Theriddler]

When they started making the P66 helmet liner for a short period of time some manufacturers stitched the duck cotton together before putting it in the high pressure mold. The fact that yours has this stitching indicates your liner is possibly an early P66 liner.

[gap]

Can you post a pic of stitching? I have a Vietnam era airborne liner with no marking I can find. Webbing suspension is marked Type II and dated May 31 1967 though.