If a 300 Rum has 4500 fullhouse loads with 180+ gr rounds down the tube, time to rechamber it to 28 guage because all it is doing is shooting "patterns" anyway.
A 300 win Mag with 190-210s will normally loose its top accuracy at 1200-1400 rds tops. Same for Weatherbys, 300 Ack Imp etc. Some of the improved 30 cal mags are loosing top accuracy at 800 rds.
Trimming brass to fit the chamber correctly seems to help barrel life instead of leaving them .050 short because of what is written somewhere. Depends on how the reamer was set up!!
The only mag that seems to beat that number right now is the 300 WSM
. Mine went 2300, took top 10 in the Nationals but groups were starting to open up. That seems to be pretty normal for the WSMS, 4 of us shooting them and all running double barrel life at least compared to other mags.