I have owned and used Leupold scopes for over30 years now, and have only ever needed to send one scope in to Korth for repairs.
Slipped and fell on a mountain goat hunt and landed on the rocks scope first.
Got off the mountain and shot the rifle (Rem 700 338 Win Mag with Vari X-III 3.5-10x40) at a rock face at 100 yards; 3 hits on point of aim at approx. 1".
A week later, before heading out on another hunt, headed out to the range to double check. Scope was way off - barely on paper at 100 yards.
Took off and mailed to Korth. They fixed and shipped back to me at no cost. Rifle was back on rifle in 11 days!
Have had one other Leupold (VX-3 4.5-14x40) that I had to re-sight in after missing a bull elk at approx 200 yards. Went to the range that afternoon and checked zero; it was 11" high and 8" left. Must have gotten bumped somewhere along the line, but do not recall such an event. Reset and it has held ever since - been almost 20 years now. I recheck every rifle before heading afield on a hunt with it, every year.
Never had any of the issues that others have mentioned over the years, but for the most part my scopes are older Vari X-III's and 3's. Only have one VX-3i (2.5-8x36 on a 250 Savage), and sighted it for 200 yards and have left it there.
Have I ever shot and adjusted my scopes for returning to zero after shooting a box pattern where I adjusted the scope for each corner of the box...no.
I set all my scopes for my hunting rifles capable of 200 yards or more, with 200 yard zeros, and then verify B&C reticle or poa at longer distances.
I have never worried about the rest of the adjustability and return to zero stuff...but I have never gotten into the long range shooting game, as I am hunter first.
Now that I have a couple of the VX-5HD (2-10 and 3-15) scopes to mount on a couple of rifles, I will need to play with the Zero Stop and repeatability techniques for using these scopes as I set them up on the rifles 3-15 will be going on a 6.5 PRC once finished).
My practice has been limited to 400 or 500 yards as our local ranges allow and/or have changed over the years.
And yes...I too have shot at that metal pig set out at 500 yards at the Chetwynd range this past year.
Hitting it with multiple consecutive shots does build confidence in one's ability, not mention the rifle and ammunition used to do it with (both of my 338 Federal's with factory ammo). An elk, moose, or even sheep is bigger than that pig! Was a lot of fun!
I have only ever shot at one animal that was close to 500 yards (475), and I under estimated the range on that first shot as I had been watching that elk come across the field through my scope at 10 power the whole way, and thought him to be at 400 yards, which is the distance that I had routinely practiced with that rifle and ammo to that point, and held accordingly. When I went to reload, I realized how far away he was, but as I had hit him (grazed the brisket just behind the front legs) on the first shot, and he had only taken a couple steps forward after the first hit and swapped directions, my second shot was adjusted and hit centre of vitals with my adjusted point of aim.