Greg, I bought an RL-300 in 1981, as well! I set it up to reload .45 ACP cases with an H&G 68 boolit and 5.4 gr. of WW-231. Other than occasional cleaning, those dies stayed set up until 2012 when I bought a 9mm pistol. The Dillon powder measure never moved, during all of those 10s of thousands of cycles that carried me through over a decade of various action pistol matches plus another couple decades of regular informal shooting.
I now have a 550 mounted about 24" from it so it's easy to compare the beefiness of the 300 compared to the newer 550. I doubt that my grandsons will ever wear out those massive twin pillars on the 300!
Semper Fi, Treetop