The volume dealers like Natchez are all sold out of the orange boxes. Cabelas isn't. You can measure the LTL measurement 4 times with a Stoney Point Gauge and get a different reading each time. In fact it's what I do. I do the LTL measurement 4 times and average the dimension.
The Walt Berger method of finding the LTL dimension is better but not foolproof. Problem is, unlike the Stoney Point gauge, the Berger method takes some prep work, like sizing a case with a bushing that allows the pill to move fairly easily in the neck and then being careful not to jam the pill into the throat and stick it. If you stick the pill in the rifling and extract the case without, you get to start over.
I've done them both and I prefer the Stoney Point method for speed.
I produce my own dummy cases for the Stoney Point gauge. Not difficult at all.