When I was in the Army in the early 80’s, my platoon sergent was a tunnel rat for about 6 months. He said that the “rats” would often have special requests that would be granted due to their unusual roles. My sergeant preferred the .45 suppressed as the ammo was already subsonic and carried more impact. He was also able to get a special should / upper arm harness made that carried extra batteries for his flash light and extra magazines for the .45
Ultimately stopped being a “rat” when a 500 lbs bomb that was accidentally dropped too close and caused the tunnel to collapse behind him. Took him several hours of alone and in the dark to find another exit.
.45 suppressed makes sense.