I don't remember who coined the rule of thumb, nor can I quote it exactly, but it was something like this:

Better to err on the short side for a rifle, and on the long side for a shotgun.

I am best suited with a rifle stock at about 13 1/2", though 13 1/4" also suits me just fine. I am somewhat cramped at 13 5/8", and 13 3/4" is positively too long (pistol grip rifle stock).

For a shotgun, with pistol grip and single trigger, I like 14 1/4" to just a tad over 14 3/4", depending on the length of the grip. On a straight gripped shotgun, with single trigger, 15" feels just right, and 15 1/4" is almost as good. With double triggers, 15 1/4" to 15 1/2" to the front trigger is best for me (straight grip). Your mileage may vary, but that catches it for me.

As a point of reference, I stand just a tad over 5'8", have a short neck and fairly wide square shoulders, wear a 34" sleeve on the dress shirt.

Last edited by GF1; 09/07/13.