Stock Height Adjustment


Dear Technoid,

I’ve been frustrated with my .410 skeet shooting. I’ve suspected I may be shooting low. It seemed I was chipping the bottoms off more targets in the 20 gauge than I should. Several other experienced and knowledgeable shooters offered their opinions that I seemed to be shooting low. I would tend to trust these shooters. Would I trust them to do brain surgery on me? No. On my wife? hmmm?

Anyway, I trust them in this matter. So, I added two layers of Walgreen’s Mole Skin Plus to my stock. Geez, I seemed to be shooting better. I had planned on getting the stock bent to match the two layers of Mole Skin, but I decided to give that intended action the ‘common sense test’ first. Gee, that Mole Skin didn’t look very thick. So I measured it. Two layers is 1/16″. That doesn’t seem like very much.

Is this passing the ‘common sense test’? Do you think bending a stock that tiny amount would make any difference?

Tom

Dear Tom,

Passing the common sense test? What on earth does common sense have to do with shooting? According to my wife, the phrase “common sense shooting” is an oxymoron.

I prefer to use masking tape instead of moleskin when I am testing height on a stock. The moleskin has a bit of “give” to it and doesn’t give as accurate a reading as the masking tape. People like moleskin because it layers up faster and is more convenient, but if you are serious, use masking tape. And make sure not to fold the tape over the sides of the stock unless you want to alter the cast.

Does 1/16″ of an inch make a difference. It might. The standard measurement system used by Churchill is that 1/16″ of an inch at face equals 1″ pattern movement at 16 yards. At skeet distances, that’s about 1-1/4″. Not all that much if you are getting a 22″ pattern from your 20, but it’s something.

I can’t see how you are setting up your gun, but if that 1/16″ makes a real difference in your scores it could be that your stock setting without the tape was occasionally putting your eye below the rib. That would make you pick your head up and produce inconsistent scores. There could also be a difference if you shoot a pre-mounted gun or shoot low gun. People who shoot pre-mounted can sometimes deal with higher stocks as they often use more cheek pressure.

The point is, just adding 1/16″ to the height of the stock doesn’t tell me much unless I know what sight picture you are starting with, your shooting style and where your gun shoots when you put it on the pattern plate. Nothing in gun fit is ever simple. It’s also important to know what kind of rib you have- raised, step or flat.

If it helps, I generally set my guns up so that I can look flat down the rib when I cheek “into the bone” with 100% pressure. Naturally, I don’t shoot with that much cheek pressure. I use about 75%~80% pressure and that brings me up so that I can see about 1/8″ of rib. I shoot only flat rib guns and avoid guns with ribs that slope down from the breech to muzzle. These are designed to provide built-in vertical lead and would force me to shoot looking flat down the rib rather than seeing a bit of rib. I’ve found that I can shoot the same gun with the same stock equally well in pre-mounted and low gun situations.

If you get a chance, test your gun on a pattern plate. That will quickly tell you how high it is shooting and how much any particular stock height adjustment effects pattern placement. After you have done your plate work and set your gun up, then go shoot targets to confirm the setting. Not the other way around. Shoot the plate with the same gun mount and style that you shoot targets with.

If the difference is only 1/16″ of an inch and you think it really matters, you have a situation. Most stock benders will only bend within a 1/16″ of an inch. Bent stocks can move a bit and bending isn’t entirely that precise a method. In a typical bending procedure, the stock is bent past the required height and then springs back to remain set, hopefully at the height you want. It’s a real art. The amount of spring back can vary with the density of the wood and some other factors. If you are really fussy about that 1/16″, you may have to end up overbending, giving it a few months to settle, and then sanding down to an exact measurement. One of my local gunsmiths refuses to bend stocks. He says that the wood never holds its bend. That hasn’t been my experience. I’ve had several stocks bent 20 years ago that still seem to fit perfectly. Many gunsmiths bend quite successfully.

The bottom line is that you will have to do extensive testing with added stock height. There is nothing wrong with shooting your gun with tape on the stock for a few months. Add and subtract tape until you get what you think you want and then shoot the gun in that configuration for a good bit. Not just a day or two. Shoot it for a couple of months to make sure. If you find that you do need the extra height, when you are certain of how much additional height you need, mark an “X” on the tape where your cheek goes (usually about 2-1/2″ or so back from the nose of the comb) and take it to the stock bender. Don’t worry about the height at nose and heel on a bent stock. Just get the height right where you put your face on that “X”.

You are the only one who can tell whether or not that 1/16″ additional height matters. It may take a lot of shooting and score comparison (use your log books for this- you do keep log books, right?) to discern if it matters to you. That’s the nice thing about adding tape. You can take your time and get it right. My guess is that if adding 1/16″ moved you up from chipping off the bottom of the target to getting a decent hit, when you plate the gun you will find that you are still in the lower part of your effective pattern and could probably take as much as 1/8″ height addition. Your effective pattern is pretty big in the skeet 20 gauge, so you might as well deal with the center of it. That’s hard to judge by watching how birds break in the air. The pattern plate is better for this.

Take your time. Enjoy the tinkering. There is so much hope in thinking that just one more layer of masking tape will open the door to all those 100 straights.

Best regards,

Bruce Buck
The Technoid writing for Shotgun Report, LLC
(Often in error. Never in doubt.)
http://www.ShotgunReport.com

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