Bonjour Pierre,
Voici ce que j'ai trouvé sur Alaska shooting Forum:
Is to put the recoil pad in the crook of your elbow, arm bent at 90 degrees, and the pistol grip and trigger should be right where your hand is at. That needs to be tempered with heavy/thick clothing takes up some distance, so you might want to go 1/2" shy of that for winter use.
Most factory rifles have a 13 to 13 1/2" length of pull. I'm 6' even, but have ape arms and find 14 1/2" is comfortable for me.
Length of pull is just one factor in making a good stock for a heavy rifle, there is also cast off, drop, recoil pad size, recoil pad construction and thickness, and cheek piece design (if present). I personally prefer a slightly lower stock, ie more drop, as it promotes rifle foll. My latest 458 Lott has a relatively straight stock, ie little drop, and it is rude to shoot, and that with just mild 350 gr loads. I'll be picking up either a laminate or structurally sound bit of walnut to make a proper stock for it.
Stocks make a huge difference when it comes to handling recoil, and most stocks are geared towards comfortably putting your head in position behind the scope, not in regards to recoil handling. Most folks don't shoot big guns that need stocks designed for recoil management.
J'espère que ça va t'aider.