DIFFERENCES BETWEEN STANDARD AND ENHANCED M GUNS Continued

(4) Barrel Assembly, PN 12524520

(a) Physical differences: The M242 ENH guns have been fielded with a ribbed barrel assembly with a chrome lined bore to provide longer barrel life. Barrel assemblies fielded with Standard M242 guns (round barrel assembly, PN 12524001 and ribbed nitride barrel assembly, PN 12524507) have nitride bores.

(b) Interchangeability: The ribbed chrome barrel assembly is useable on all configurations of M242 guns. The ribbed chrome barrel assembly components (with the exception of the barrel) are common with the ribbed nitride barrel assembly (PN 12524507). The round and ribbed nitride barrels will fit and function with the M242 ENH; however, their use is not encouraged.

(5) Link Bridge, PN 12524584 (Standard M242, PN 12524489 and PN 12524488) Rear Upper Link Stripper, PN 12524576 (Standard M242, PN 12524484) Rear Lower Link Stripper, PN 12524577 (Standard M242, PN 12524487) Forward Upper Link Stripper, PN 12524578 (Standard M242, PN 12524485) Forward Lower Link Stripper, PN 12524579 (Standard M242, PN 12524486) Forward Feeder Assembly, PN 12524574 (Standard M242, PN 12524273) Rear Plate Assembly, PN 12524575 (Standard M242, PN 12524190)

(a) Physical differences: The M242 ENH bridges have an integral attachment spring latch. Both the upper and lower feed paths use the same bridge, as opposed to the two different bridges used on the Standard M242 feeder assembly. The four link strippers used on the M242 ENH have attachment buttons installed to secure new bridges instead of the capscrews used on the Standard M242 feeder assembly. The attachment buttons are positioned so that the new bridge will always be installed correctly. Both the forward feeder assembly and the rear plate assembly have had material removed from the outer edges to allow clearance for the new bridge's attachment spring.

SPRING LATCH

SPRING LATCH

Feeder Handle M242

(b) Interchangeability: The M242 ENH bridges and link strippers are not "one for one" interchangeable with the Standard M242 feeder assembly bridges and link strippers. The M242 ENH must only use the new bridges and link strippers. The forward feeder assembly and rear plate assembly are useable on the Standard M242, but must be used on the M242 ENH. The M242 ENH bridges and link strippers could be installed on a standard M242 if both M242 ENH forward feeder assembly and rear plate assembly are installed at the same time. All of these M242 ENH components are part of the M242 ENH feeder assembly, PN 12524100-1. While the new feeder assembly must be used with the M242 ENH, it will work interchangeably with the Standard M242 gun.

(6) Gun drive motor, PN 12524409 (Standard M242, PN 12524494 and PN 12524473) Feed Select Solenoid, PN 12524404 (Standard M242, PN 12524168 and 12524181) Feed Select Solenoid Harness, PN 12524403 (Standard M242, PN 12524167)

(a) Physical differences: The M242 ENH gun drive motor is a 1.0 horsepower direct current motor that contains a jumper wire in the motor/turret jack (J1) between pins J1-M and J1-M. This jumper wire provides a means for vehicle built in test (BIT) to determine whether the turret gun wiring harness is properly attached to the gun drive motor. This jumper wire is the only difference between the M242 ENH gun drive motor and the Standard M242 1.0 HP motor (PN 12524494). The M242 ENH feed select solenoid (FSS) and FSS harness contain a jumper wire in the 14 pin connector (P1) between pins P1-K and P1-N. This jumper wire provides a means for vehicle BIT to determine if the feeder assembly handle is properly closed. This jumper wire is the only difference between the new M242 ENH FSS and harness, and the Standard M242 FSS with detachable harness (PN 12524168) and FSS harness (PN 12524167). The FSS solenoid bodies are identical in the two configurations.

(b) Interchangeability: The M242 ENH will function with any gun drive motor, FSS or FSS harness; however, if the vehicle BIT attempts to check for proper gun drive motor connection and feeder handle position, it will report faults if the new gun drive motor and FSS are not installed. It is highly recommended that only the new components be installed in the M242 ENH gun. The new motor, FSS, and FSS harness are fully interchangeable with the standard M242 gun.

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