The same thing happened to me with a used Bugout I bought about a year ago. The axis lock bar was gritty, and it never got better no matter how many times I opened and closed it. I compared it to another Bugout I had. The difference I saw was that, with the gritty one, the lock bar would rotate as I opened and closed the knife. With my other perfectly smooth Bugout, the lock bar didn't rotate. Try putting a torx wrench in your lock bar, open and close it, and see if the wrench rotates.
My used, gritty Bugout came with aftermarket scales. I contacted Benchmade about the problem, and they told me to send it in for a lock bar replacement. They didn't care that it had aftermarket scales. I sent it in, and it came back working perfectly two weeks later. I just had to pay to ship it to them.
My used, gritty Bugout came with aftermarket scales. I contacted Benchmade about the problem, and they told me to send it in for a lock bar replacement. They didn't care that it had aftermarket scales. I sent it in, and it came back working perfectly two weeks later. I just had to pay to ship it to them.