156. Ground Signals of Series M17A1 to M22A1 and of Series M17A1B1 to M22A1B1, in-clusive, are respectively designed to produce the same signals as those of Series M17 to M22, inclusive. However, they are for use with rifles or carbines equipped with appropri-ate grenade launchers; so the proper firing device must be used. Both the series of sig-nals are identical, except that those marked with the last two letters B2 are of steel construction. Both these series of signals are 10.4 inches long, including the tail assemb-lies, and the hollow stem supoorting the tail is of larger diameter than the M17 to M22 series. These signals, when launched with the proper devices, rise nose first to the re-quired altitude, instead of starting tail first and reversing at 100 feet, as is the case with series M17 to M22. They are identified as to type and color by the same code as series M17 to M22, but the paint and embossed lettering are on the head of each signal instead of on the tail vanes. See Fig. 61.

Figure 61. – Signal, Ground, White Star, Parachute, M17A1

Operation With Rifle or Carbine

157. Current models of Ground Signals M17A1 to M22A1 and M17A1B1 to M22A1B1 are for use with service rifle or carbines equipped with the appropriate model grenade launcher. Early lots of the above signals contained in the tail s special cartridge, known as CART-RIDGE, RIFLE GRENADE, CAL. 30, M3 and are use with RIFLE, U.S. M1917, M1903 and M1. No attempt should be made to fire the above signals from CARBINE CAL. 30, M1 or M1A1, unless the Cartridge M3 is removed from the tail and replaced with CARTRIGDE, CARBINE, GRENADE, CAL. 30, M6. This is accomsplished by removing the cork and clip from the tail of the signal and substituting the cartridge M6 for the original Cartridge M3. In more re-cent lots the signals are packed in assortment. The assortment includes 48 signals in a wooden box, which also contains 50 Cartridges M3 for use with the Rifle M1917, M1903 or M1, and 50 Carbine Grenade Cartridges M6, for use with Carbines M1 and M1A1. When the special cartridge is fired, it ginites the propelling charge in the signal, which is redu-ced to compensate for the cartridge charge. The combined charge in the cartridge and signal then projects the signal head first to the required altitude.

With the proper cartridge and grenade launcher the following steps should be taken to fire Ground Signals M17A1 to M22A1 and their counterparts of series M17A1B2 to M22A1B2:

(a) Unseal the fiber container and examine the signal to see that the case is not dented and that the tail is straight and attached firmly to the case.

(b) Remove the cork and clip from the tail and place the signal on the launcher.

(c) if the signal is of the earlier lots, remove the cartridge from the cork assembly and load the rifle. If it is from the newer lot, use the appropriate cartridge, which is separat-ely packed.

Storage

158. General rules for the storage of pyrotechnic ammunition detailed in paragraphs 9 to 12, inclusive, apply to ground signals. Faulty Dr deteriorated signals should be disposed of as detailes in paragraph 17.

Safety Precautions

159. The use of the proper firing mechanism for firing ground signals cannot be too fully stressed. The following facts must be remembered:

(a) Use only CARTRIDGE, RIFLE, CAL. 30, M3, when firing the RIFLE, U.S., CAL. 30, M1917, M1903 or M1.

(b) Use only CARTRIDGE, GRENADE, CARBINE, CAL. 30, M6, when firing with CARBINE, CAL. 30, M1 or M1A1.

(c) In handling signals, the primers should be protected against sharp blows or from con-tact with sharp instruments which might cause them to fire.

(d) Discard signals with dented or cracked cases, and with bent or deformed fins and tails supports.

(e) When firing, care must be taken to keep all personnel clear of the muzzle of the pro-jector, rifle, or carbine and below the level of the signal when it is placed on the laun-cher. Care must also be taken into aim the signal so that it, or its parts, will not fall on friendly personnel or ammunition stores. Where practicable, some measure of cover should be taken to avoid falling signal cases.