Home Forums Hunting & Shooting Gunsmithing Rifle Stock Cast Off

Can somebody explain cast off in a rifle stock and how you go about estimating an appropriate amount for an individual shooter? I'm an amatuer stock "fitter" and am interested in shaping a rifle stock to fit my particular needs. Many thanks for your help.

http://www.hallowellco.com/abbrevia.htm

Cast Off - An offset of a gun stock to the right, so that the line of sight aligns comfortably with the right eye while the butt of the stock rests comfortably on the right shoulder. Almost all right-handed shooters benefit from a little castoff and most custom built guns are made this way. The only question is how much. The castoff of a gun is about right when, with the gun comfortably mounted, the front bead lines up with the center of the standing breech. A stock offset to the left, for shooting from the left shoulder is said to be Cast On. See Eye Dominance.

Cont. below

Eye Dominance - Although we have two eyes for depth perception and for spare parts, there is a natural tendency for one eye to take precedence over the other, regardless of the relative visual acuity of each eye. It is a fortunate condition when the eye on the side of the shoulder where one is comfortable mounting a gun is also the dominant eye.

To test for eye dominance, pick out a small object several feet away. With both eyes open, center your right index finger vertically over the object. Close your right eye. If your finger appears to jump to the right, you are right eye dominant. Then open your right eye and close your left eye. If your finger remains in position in front of the object, you have confirmed your right eye dominance. Alternatively, if in the above test, upon closing your right eye your finger remains in position covering the object, you are left eye dominant. If you close your left eye instead and your finger appears to jump to the left you have confirmed your left eye dominance.

Eye dominance problems can be treated with 1. A severely-cast, cross-eye stock to bring the dominant eye in line with the gun's line of sight, 2. A patch over the dominant eye, or just a small piece of frosty Scotch tape on shooting glasses intercepting the dominant eye's line of sight, 3. Fully or partially closing the dominant eye, or 4. Learning to shoot from the dominant-eye shoulder. While less convenient, methods that retain the use of both eyes better preserve the ability to perceive depth in three-dimensional space---a great benefit in wingshooting.

Thanks for the info. I just tried your test and when I closed my right eye my finger stayed in place. I guess this means I'm left eye dominant. I am right handed and have been shooting rifles, handguns and shotguns with my right eye forever. So I guess I've either adapted, have an excuse for poor shooting, or misunderstood your instructions. In general, should a rifle stock be finished with zero cast-off from the center-line of the bore? Again, thanks for your help.

PS - Looks like I jumped too far ahead and missed your first comment on all stock benefitig from a little cast-off.

A stolen image.

Ya know what they say about a picture being worth a thousand words. Thanks again

That was the same statement made about the image on the site where I .....borrowed the pic.

I can say what works for me. 1/4" at top of butt,3/8" on bottom.LOP varies from gun to gun but usually in the 14" realm.
I am 5' 6'' and a friend who I make few stocks for is 6'3" and the same works for him also.
Not saying it is gospel, but it does work for me. It will also vary on how thick your stock is where your cheek weld is.

Try cutting your stock intially so the balnk has enough for a full 3/8" cast. Bring the left side of the stock straight back with no cast and then keep cutting on it until you achieve what is right for you.You can always cut the right side back.

Ask around for an owner of an one of the fully adjustable Anschutz target rifles. A likely source might be a small bore club. One can adjust everything on those rifles. Tweak one until it's just right, take some measurements, and apply them to your build.

A second source might be a high end stock maker. Tell them of your intentions and offer to compensate them for their time. Doing a build right now and have about 1/4 inch cast off. Like those above mentioned, other aspects of the stock will also enter into the equation.

Thirdly, one might simply go to a shop, try their full array of arms, and duplicate whatever feels and points the best.

Last. One might also get some help from competitive sheet/trap shooters. They do things in a hurry, and proper fit really helps things come together. One often sees competitive shooters with really fine guns, and they've applied a big chunk of bondo to the stock and rasped it down to the desired dimensions. With rifles, we often have lots of time to align things, and can make do with rather sloppy fits. It is really nice though when one can take the time to fabricate a gun that's right from the beginning.

Edited: Just pulled down Wesbrooks Professional Stockmaking book. He provides an excellent description of the function (eye alignment) and techniques for accurately measuring and marking a stock for cast-off and toe-out on page 92. His book is getting near impossible and very expensive to acquire. When I buy the farm, be sure to hit the wife's yard sale.

Thanks to all for the great information. This is the sort of stuff that makes a Forum worth joining!

You have gotten obvious contradictions at every step... SHotguns are nothing like rifles and cast is not used in rifles to make for a comfortable fit. Rather, cast is used with rifle stocks to redirect recoil more than anything else.

Cast a boomer "off" and your cheek will be most unhappy. By the same token a little "on" will gentle a big rifle tremendously. Off will cause the comb to twist up into your cheek while on will reduce barrel rise and send it a bit to the side.

From the bench the result may be a bit jumpy and squirrely, but in field use the muzzle will not rise as far or as fast as in a straight stock, but will "rotate" out and away from the cheek.

Most rifle stock makers would use no more than 5/16" at the heel and perhaps 1/4" at the toe to reduce apparant recoil.

Rifle stock fit is not something that one "feels" or senses like a shotgun and adequate sight picture is easily, quickly, and reliably obtained with a lot more leeway than a shotgun.

Building in cast on a light recoiling rifle is not needed at all...