4 hour LTs in Vietnam, Total BS. No one wore rank anyway.
As to reloading bolt guns. Don't get the idea that if someone says they are loading that you can get to them before they are finished. Bolt guns can be and are loaded pretty quick. M1903s are about the fastest I've seen.
I started shooting HP in the Mid 70s, ARs on the rifle range were non-existent. M1As weren't available, and the DCM parceled out Garands at a slow rate.
Most civilian shooters used Bolt guns, Winchesters and Remington's or Springfields in EIC or service rifle matches.
At that time Setting Rapid fire was 60 seconds for bolt guns, 50 for gas guns, Prone Rapid was 70 and 60 respectively. That's from standing to sitting/prone. Also then, in EIC matches you had to load from the person, not laying the reload on the ground.
These guys were pretty quick. Mind you, not just reloading and firing, but getting hits in the 7 inch 10-X ring at 200/300 yards.
Not fast enough for you, then think about the Rattle Battle, or Infantry Trophy Match, where you start out at 600 yards, firing as many rounds as possible in 50 seconds.
If you ever watched one of those matches, you would know that bolt guns and stripper clips aren't as slow as you think.
Now everyone is going to ARs, quick mag changes and even scopes. But you can still see bolt guns at CMP matches. Take in a CMP Springfield match. All versions of as-issued 1903s. Personally I never get the scores with my Garand that I get with my M1903A3. And I shoot the 'A3 every bit as fast, if not faster then my Garand.
The Springfields are smooth and fast, but my AMU built Model 70 is faster yet.
On TV shows you see cops yelling "reloading" when they are out of ammo. Go to a USPSA match, these guys are reloading faster then they can yell "reloading"