Lets consider an average Brit pattern game gun; 12 gauge, 28" barrels, 14 1/4" LOP. It will weigh 6 1/2#, balance 4 1/2" in front of the front triger, swing unmounted at 1.45, swing mounted at 6.38, and have a half weight radius of 10.17. It will have these numbers no matter who holds it. Differing people will have differing interpertations/reactions to these numbers, but the gun and the numbers do not change. Exactly the same situation exists with stock dimensions - shooters must develop individual sets of dimensions for optimal stock fit. But, a 14 1/2" LOP is a 14 1/2" LOP no matter who is holding the gun or how he feels about it.
How to use this? Lets say we have a seller and a buyer far enough apart that travel to see the gun is not practical and the gun is of moderate value. The seller says he wants a 6 1/2# game gun, expecting to get a gun very like the above average game gun. The seller sends him a used AyA M-52 that weighs 6# 9 oz and balances at 4 1/2" to the front trigger. The buyer is unhappy. Why? Because the gun has an unmounted swing of 1.67 and mounted swing of 7.05 - the buyer was expecting a "faster" swinging gun. Had the buyer's expectations been discussed further and in numbers, the seller could have sent a Dickson BLE at 6# 8 oz, 4 3/8" balance, 1.50 unmounted, and 6.76 mounted; much more likely to suit the buyer's handling expectations.
Perfect stock dimensions and perfect balance are judgements. Unless you are correlated to the person doing the judging, such pronouncements are meaningless.
