XM27 Riot Control Gas Mask

Unknown Silicone M17 Prototype
XM27 Riot Control Gas Mask (Unconfirmed Designation)
The XM27 and its Waterproof Carrier Pouch.
Preceded by	ABC-M17
Succeeded by	XM28E4 Riot Control Gas Mask
Prototype	Yes
Filter	M13 Series Filtering Elements
Filter connection	22mm
Made in	United States
Period	1966-1968
Users	N/A
Issued to	US Army
Manufacturer	Mine Safety Appliences(?)

In 1966, the 1st Cavalry Division requested a compact and lightweight protective mask when it was found the standard ABC-M17 Field Protective Mask proved far too bulky and gave an excess of protection when dealing with Riot Control Agents deployed to flush Viet Cong from their tunnels. During trials for a lightweight protective mask, one contender used the ABC-M17 mold, however constructed of a transparent silicone rubber instead of the typical black natural/artificial rubber blend (some references state a green silicone variant was also tested). The idea was that the silicone would be lighter in weight and that the transparent material would allow soldiers to identify each other more easily.

In addition to being produced of transparent silicone rubber, the prototype also lacked lens frames and utilized a C15 Head Harness, rather than the typical C8R1. The carrier for the mask was a small, waterproofed duck canvas pouch, as the mask was not intended for use with CBR Agents and did not need a wide variety of accessories. Exact figures of production are unknown, and it did likely not last long as the XM28 Series Masks proved far more lightweight and compact.

Production of the XM28 began in 1968, and one reference hints that some remaining examples of the silicone M17's were used as training aids, as it allowed the internal workings and construction of the ABC-M17 to be fully visualized.

Additional Notes:

• The designation "XM27" is unconfirmed and was likely started by Bart Wilkus due to the design's close proximity of development with the XM28 Prototypes.
• Two examples are currently known to exist - the first (and perhaps most well-recognized) formerly belonged to Bart Wilkus of http://nofuture.com/gasmasks.net/ and is currently owned by collector Taro Hanrahan, and the second resides at the archives of the Fort Leonard Wood Chemical Warfare Museum.
• The 'amber' color of the rubber is due to aging and discoloration of the silicone. The masks would have been completely transparent originally.

Gallery:

The XM27 Facepiece.

A heavily-discolored (or solid-colored) XM27 residing at the archives of the Fort Leonard Wood Chemical Warfare Museum.

The XM27 on display (bottom right) at the Fort Leonard Wood Chemical Warfare Museum.

The XM27 in the Collection of Taro Hanrahan.

Side View.

Side View.

The C15 Head Harness.

Interior of the Mask.

Detail on Markings.

References:

1. Chemical Defense Equipment, Figure 16-5
2. Modern Forces - XM28 Riot Control Gas Mask
3. Le Masque à Gaz, Page USA 5
4. Le Masque à Gaz, DETAILS
5. Mask History - Infantry or General-Purpose Mask by Major Robert D. Walk