This is the M15 White Phosphorus ("Willy Pete") Hand Grenade made and used by the U.S. during WWII and after.
This is a bursting type grenade, scattering phosphorus particles over a 25 yard diameter area. WP produces an instantaneous dense white smoke upon exposure to air, burning at 5000°F for 60 seconds. WP grenades were developed for screening purposes, but they were found to be effective anti-personnel weapons as well..
The body is made from 18 gage steel and the fuze is a M6 or M206 detonating type.
(M6 Shown here.)
|M15 Sectional Diagram, U.S.M.C.
M34 WP was developed as an improvement over the M15.
The body is slightly lighter with a grooved surface which burst more readily. While the amount of WP filler was about the same, the effective radius increased about 25%.
The body was provided with a grooved and tapered base, which allowed it to be mounted on a rifle grenade adapter. Since the bursting radius was now greater than the typical throwing distance, use as a rifle grenade was necessary when there was no available cover.
The color code is found in two styles. Earlier gray body with yellow markings, and later (NATO) light green with yellow & Red.
|The two M34 grenades shown are not your "typical" WP types.
The one on the left is different, with a raised fuze bushing rising off the grenade body. This is typically found flush. The interior appears never to have been filled. The markings are a font style found on Australian made copies of the American design.
Another odd feature are faint traces of a previous "WP" stencil under the gray paint.
An advanced collector has suggested it may be a concept prototype, possibly from China Lake.
The one at right is an injection molded plastic grenade model which was described by the seller as:
"...made by the Army as a recognition training aid. Constructed at Ft. McClelland Alabama."
It and a few others were offered for sale shortly after the closing of Ft. McClelland.
Why it was made smaller than the standard M34 dimensions is not clear. It is solid except for a full length fuze well and nicely detailed.
Any additional info or comments welcome!