I worked as a Small Arms Repairman, 45B MOS, while I was in service.
I believe all the numbers posted are accurate.
The only weapons that were maintained with logs designating the actual number of rounds fired through the weapons were Match rifles and handguns and Sniper systems and these weapons did not have a set standard of rounds fired before replacement.
The Serviceman issued one of these weapons could have it rebarrelled at any time he determined that the weapon was not shooting to his standard.
I know some of these guys had their weapons rebarrelled every 1000 to 3000 rounds.
Service weapons are turned in for rebuild when the unit armorer determines the weapon is in need of higher echelon repair.
Throat erosion, bore wear, and muzzle condition all determine whether a weapons qualifies for turn in, not the actual number of rounds fired.
I do know that training weapons have a far greater number of rounds fired through them before turn in than do weapons used in actual combat and this is generally because training weapons are better maintained and cleaned with a regularity that borders on religeous fervor.
M16A1 rifles were turned in far less frequently because of excessive barrel wear than M14 rifles and I know this has to do with the fact an M16 can be cleaned from the breech and an M14 or M1 Garand must be cleaned from the muzzle when using service issue jointed cleaning rods.
Most personnel did not use the muzzle protection ring issued with the jointed rods, most were never instructed how to use the protection ring properly and figured it was something they didn't need and pitched it.
Consequently I saw far more M14 barrels with excessivly worn muzzles than out and out bad barrel bores or excessive throat wear.
Chrome lining the barrel bores and chambers oif M14 and M16 rifles definately played a big part in this reduced wear as compared to an unlined M1 Garand barrel.
A normal non-chrome lined M1 Garand barrel, be it wartime or post war will exhibit about one caliber on a throat guage for every 1000 to 1500 rounds fired.
Muzzle wear does not come from firing but from improper cleaning procedures and mishandling.
The use of a rifle as a pike does the muzzle of the weapon no good.
Bayonets should have been eliminated with the obsolescence of the smoothbore muzzleloading musket in my opinion.
Based on what I saw and worked on in service and assuming your question pertains to a personally owned M1 rifle that will be shot for pleasure or competition and properly cleaned and maintained and assuming a barrel that reads about 3 on the throat guage and has a tight muzzle and you do not plan to regularly clean the rifle with a military issue jointed cleaning rod,,,
I will venture to say your barrel has a good 3000-4000 rounds of accurate service life and another 3000-4000 rounds of servicable life with a reduction in group accuracy overall.
In other words, 6000 to 8000 rounds, which is way more than most people will fire through one weapon in a lifetime of shooting. HTH
