Agree on availability of brass, but my experience was different, however I just noticed your velocities. Don't remember my velocities but they were very close to same bullets in a 243 Win.; quite a lot lower than yours, which probably explains the different experiences.
I shot my 25” savage at 3900fps with a 90smk. It was happy and more accurate from 36-3750fps.
I don't remember what year I had Dtech build my 243 WSSM upper, but I used it exclusively for at least 11 or 12 years when landowner decided AR's were no longer allowed on his ranches.
When I had it built, I had a feeling components would soon become scarce, as most manufacturers had already stopped offering bolt guns in that caliber, so I stocked up with enough to last me a lifetime. Got a pretty good deal on some Federal brass, which, as it turns out was much better than WW brass IMO. It was a little softer, making sizing much easier yet hard enough to be very easy (in my rifle) on case life. In fact, I can't remember ever having a case fail and I shot it a lot! Also, never lost a piece of brass after buying one of reb8600's brass catchers.
Unfortunately I didn't keep record of the round count, but it was my go to rifle for predators, hogs and culling whitetails and I shot it a lot! The barrel was still shooting little bitty groups withe the 87 gr. Speer BTHP and the discontinued100 gr Nosler Solid base bullets and the bore scoped out well.