I personally don't think it is necessary. However, some feel compelled to do that one "thing" that they believe will give them the edge, either in competition or the game field. I tend to believe it is mostly mental, like the routines some ballplayers do before a game. If someone wins a traditional archery shoot and says he owes it to weighing his arrows to 2 grains, then it is likely the rest of the shooters will start weighing arrows, when the fact is that more practice is probably the answer. I also shoot old bows and old guns but I believe in most cases, the weapons shoot better than I will ever be able to hold, so if I can hit what I aim at, then I am usually satisfied. I've proven this on occasion when I had access to a machine rest and been able to see what some of the old pistols will do.
I was playing around one day with a 65# recurve bow and shooting at a hay bale with matched aluminum arrows. That day, I could not shoot groups better than 3-4 inches at 20 yds. One shot hit high and turned the bale on its side, so I decided to shoot at the arrow shaft sticking out. I was pretty surprised that I broke that arrow in half with the first shot. It may have been luck but I believe it goes back to the focus problem that instinctive shooters have to overcome, which is picking that very small spot and making the arrow go there. The historical accounts I have read indicate that most primitive archers on the various continents were pretty good shots and I can almost guarantee they didn't weigh arrows 500 years ago. Their skill came from complete familiarity of something they lived with daily since childhood.
