Accuracy loss can look quite different depending on whether you're dealing with pistol or rifle barrels. When did you start seeing a decrease in each, and what signs made you aware of it?
I noticed my AR was losing accuracy after about 12k rounds. The first indication was some vertical stringing that just wouldn’t disappear. A borescope check showed throat wear and fire-cracking. For the pistol barrels, they tend to last a lifetime unless you’re shooting major PF loads all the time.