Man, talk about a different time. Just try "trading" your rifle these days. Pretty sure leadership would just hang the offender from the nearest tree.
During the Korean war there were many different infantry weapons to choose from. It was mix and match. If a guy in my Dad’s platoon got wounded or worse his weapon(s) was fair game. What he told me was some of the guys liked the captured Russian burp gun so much they started to carry it. It was a really good weapon. Then they realized the sound of it could potentially draw friendly fire so that didn’t last long.
My uncle was in the 24th division on occupation duty in Japan and he was thrown into Korea right off the bat. He said the norks invaded on a Saturday and he was on a ship the next Tuesday headed to Korea. He carried an M1 Carbine with 30 rd magazines tapped together. I suspect it was probably a WWII variant that was semi-auto because I have heard him talking about filing down the sear to make it auto, ever how he did it. When he got off the ship they were initially handing out a few rounds of ammo to each soldier, 2-3 and the phrase try not to use it, WTH! He said the closer they got to the norks the more ammo they got. He liked the M1 and carried it his entire tour of duty.
My mother-in-laws father also served in Korea a year into the war though is when he got there and he would trade for an M1 carbine and his Lt. hated the M1 carbine with a passion. Reynolds, get rid of that piece of crap and get you a garand right now! Yes sir and he would scrounge up a garand and carry it for a while until he could trade again.