i preordered my x-17 this summer as well. I had to use some 600 grit sand paper to even be able to get the takedown pin close to going in. Definitely a build up of the finish, but it works now. Also my timney trigger wouldn’t work with it for some reason (safety wouldn’t engage)? Swapped a Geissele in and had no issue with it. So don’t buy it if you have a timney and don’t won’t to replace the trigger.It was tight initially. I think it was a slight build-up of the cerakote on the back lug where it goes into the rear of the receiver and stock. After removing and reattaching it a few times it is still snug but goes on and off much easier and the take-down pin can be pushed by hand. I would rather have it tight than loose.
After paying and waiting for 14 months on the Stryker lower (got a refund after 14 months), I was just happy to have a lower that takes pmags.