I've had a Mk I for 35 years. It's still capable of better accuracy than I am. I used to frequent an indoor range where I'd dump a 50 round box of ammo out on the table, clip the flap of the empty cardboard box to the target carrier, run it out to 25 yards and proceed to put 80% of the rounds through the box using a two hand hold and producing a flip every time I hit it. Wasn't unusual to look up from concentrating on the task at hand to see shooters on either side gawking at the riddled box when I ran it back.
The Mk I just made it look easy.