HR has this concept of compa-ratio, which is your salary divided by HR's desired midpoint. (Note that the desired midpoint is NOT necessarily the average of min and max and varies by role.) This is industry-wide, not unique to USAA. At 100%, you're considered to have "mastery" in that role. HR's ideal path is to hire someone into a role at ~90% of the midpoint and promote them around the time they get to 100%.
For example, if a role has a range of $100,000-$150,000, HR might want to keep everyone in that role around $125,000. If your salary is $130,000, you'd have a compa-ratio of 104%. If someone gets too far above the desired range, they want to start making changes such as moving that person into a role where their salary is closer to the midpoint or cutting into your annual raises to help bring others on the team up.
So if your manager told you that you're at "105% of the range," they were not telling you the whole truth. You may be at 105% of the desired midpoint, but the range goes much higher. And HR can/will go above the "max" for the right person.