Avoiding the Terror of Shotgun Stock Shims
How many times do we have to hear it? The Brownelli-Binford 9100 comes with stock shims that gives you “that perfect fit”! Nothing could possibly be further from the truth, but if you say something goofy long enough and loud enough, people apparently start to believe it.
Shims can only change the way the buttstock is pointed away from the receiver. Shims don't change pistol grip shape, comb width, shims don't do anything to change the relationship between your hand and the trigger. Shims don't change the comb height, either.
It sometimes gets even worse. For example, let's say you want more drop from your buttstock, so you change a shim. But, that unfortunately isn't all you changed: you changed the pitch of your buttstock as well, which can have several unintended consequences. You might have a change in muzzle rise and point of impact, things you didn't want and never considered.
Patrick Kelley has written about the “Perfect Pitch.” Patrick writes, “Pitch is rarely discussed but is important. In simple terms proper pitch will have both the Heel (top) and Toe (bottom) of the butt (recoil pad) fully planted into your shoulder pocket. Here is a theoretical example.
We want to set up our shotgun to be fired against a brick wall. We want the least amount of muzzle movement under recoil while shooting. To do that we would set the pitch to zero so the recoil pad would make full contact with the wall (pad @ 90* =perpendicular to the rib =zero pitch).
This results in the barrel pointing downrange and parallel to the ground. Now if you put that zero pitch recoil pad against the curve of your shoulder, the gun will be pointing way high! If you lower the barrel back to parallel with the ground you would only have the toe of the recoil pad touching your shoulder. Firing a quick pair in this configuration would not only have you in pain but also have the muzzle heading for the sky! Why?
Because the recoil impulse will close the gap between the heel of the recoil pad and your shoulder as it pivots on the toe of the recoil pad. Or the toe will slip down your shoulder, pivoting the muzzle upward between your hands. The reverse happens when more heel is in contact with the shoulder. Is the light coming on? Too little pitch and the muzzle moves goes high, too much pitch and the muzzle moves down. You want a flat shooting shotgun? Check your pitch!”
Rollin Oswald's https://www.amazon.com/Stock-Fitters-Bible-Rollin-Oswald/dp/1451570384 is still a must-read treatise on the subject. Though there is never universal agreement on much of anything, there is essentially complete agreement that gun fit is tremendously important. Unless you are an identical twin, the chances that anyone is going to come away with identical interpretations of the same shotgun are exceedingly low.
Major gun manufacturers that produce shotguns in significant quantities of course want their guns to fit as many people as possible. Sometimes, it pretty much works, with 3,000,000 Browning Automatic-Fives, 12,000,000 Remington 870s, and over 4,000,000 Remington 1100s sold. If these guns were deemed unshootable by the majority of hunters and shooting sports enthusiasts, these sales numbers would not be plausible. Yet, of these twenty million or so shotguns sold, not one of them came with adjustment shims. The best-selling O/U of all time, the Browning Citori, comes with no shims, either. Most O/U's don't come with shims and won't, for shims are no cure for stock dimensions and they can cause just as many problems as they purport to address.
Personally, I suppose that I'm lucky, for most conventional shotguns fit me well, but certainly not all of them. Some years ago, I bought a beautiful Winchester Model 23 Pigeon Grade SxS, a gun that I really wanted to love. It didn't fit me at all, it was just completely wrong for me, and it would have taken a complete custom stock to get it right, for me anyway. The same was true of a new Browning A500G, a Citori 20 gauge Upland Special, and several others. Somebody, somewhere must have thought those guns were stocked properly for someone. Perhaps they were, but certainly not for me.
One oddity is the Browning Automatic-Five Light Twenty. Even though I've hunted with A-5's all my life, and the buttstocks of the Light Twenty interchange with the Sweet Sixteen and the Magnum Twenty, trying half a dozen or so brand new A-5 Light Twenty models ended in frustration. As long as I held ten feet or so below the bird, it vaporized into dust every time. Back when I bought a new Beretta 303 Trap with gorgeous wood, it was apparent the well-figured stock wasn't going to work for me at all: too much comb, way too much. I'll never forget the look on my stocksmith's face prior to him conducting major surgery to the factory stock. He looked over at me several times before destroying the factory finish, repeatingly asking, “Randy, are you SURE you want me to do this?” Absolutely I was sure, for a shotgun that doesn't fit is far worse than a dog that won't hunt, for you still love the dog. Hopefully, these tales of a few of my sagas will reduce your own personal “Saga Count.”
The traditional “normal” dimensions may not work and may never work for you if you are female, have an extremely long neck, or all of the human factors that compel us to not wear the same clothes, or other people's clothes. Shims can be useful, in the most minor of changes, but sometimes a couple quarters under a buttpad or a few thousandths thick piece of plastic added where the buttstock meets the receiver can be more effective.
The best shims, by far, are the shims that we never need to attempt to use.
Copyright 2017 by Randy Wakeman. All Rights Reserved.