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How To Check A Shotgun For Proper Fit





NYECOGunsmith

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This one got lost when we went to the new software, found a copy of it I had on a thumb drive so am restoring it here.

How To Check A Shotgun For Proper Fit

For all this, make sure the gun is UNLOADED!

Length of Pull

First check the length of pull. Quick "field" check for this is to place the UNLOADED!! shotgun in the crook of the arm that you pull the trigger with. Right handed? Use the right arm, etc. With your forearm parallel to the ground, and your bicep 90° perpendicular to the ground, lay the stock on your forearm so that the but stock is up against the bicep, now extend your trigger finger and curl it as though you were going to fire the gun.

Does the first distal pad of your index finger meet the center of the trigger?

The length of pull should be such that it allows your cheek to come onto the comb without having to stretch your neck out to get it there, and at the same time, it should allow you to have roughly an inch and a half (1.5”) of distance between your thumb of the firing hand, and your nose. This keeps you from getting smacked in the nose by your own thumb when the gun fires.

If it does, the LOP (length of pull) is OK for you. If it doesn't reach that far, the gun is too long and you will probably shoot high with it, and the buttstock will kick a bit.
However, a stock that is a bit too long is preferable to one that is too short.
IF it goes beyond that point, the stock is too short, it's going to kick the crap out of your cheek and your shoulder (cheek piece and buttstock will BOTH smack you in this case).

If the length of pull is too long, installing a thinner recoil pad, or cutting the stock are the ways to fix it.

If it’s too short, install a longer pad, or install an adjustable recoil pad that lets you alter it through a range of pulls.

This last one is a good idea if more than one shooter will use the gun.


Line of Sight or Sight Picture Check


Next, if the gun has a mid point bead (two beads, one at the muzzle, one at the middle of the barrel called the mid point bead) with the gun UNLOADED and your eyes closed, throw the gun to your shoulder and without adjusting its position in any way, open your eyes.
Do you see two beads, or just one? Just one is perfect, the gun will shoot point of aim/point of impact for you. If you see two beads, is the front bead above or below the middle bead?

Above it means the gun will shoot high, this is the way a Trap gun is normally set up for most shooters.

If the middle bead is higher than the front bead, the gun is going to shoot low, and kick the hell out of you as the stock rises to your face. Do the above test a dozen times to get an average feel for where it will shoot for you.

Shooting it at a patterning board (CCSP has one on range #1, shotgun park) will confirm this.

Ideally, all you will see is the front bead, or the front bead with the midpoint bead perfectly lined up with it so that they appear to be just one bead. The top of the receiver and the vent rib (if one is present) should be invisible to you at this point if the gun fits you.
Personally , I set my shotguns up so that they shoot high, the top of the mid bead is at the bottom of the front bead for example, because I prefer to always be able to see the bird, rather than cover it, and at the same time this allows me to see what is behind the bird as well, you know, be sure of your backstop!

Of course, if the stock comb is too high, pitch is wrong, drop a the heel or toe is not right for you, this sight picture will not be obtained.

Next, you need another person to help you. With the gun UNLOADED, and checked to be as such by EVERYONE PRESENT!! NO MISTAKES HERE! you throw the gun to your shoulder with eyes closed as above, and have a second person at the muzzle look down the barrel with YOUR eyes still closed.

They are looking to see if you are shouldering the gun canted (twisted to one side or the other from a perfect vertical orientation) , then, with you holding it still, they tell you to open your eyes.

They should see the bead(s) in perfect alignment with the center of whichever eye is behind the barrel(s)/receiver. If not, you will be making unconscious adjustments to it while trying to swing the gun on the bird. The pitch, cast, and drop all affect this.

No gun will ever be always perfect for you, because the thickness of your clothes will alter this, so will you losing or gaining weight.

But these things should all be close to right on most of the time, given slight variations in your attire and weight.

The gun's balance point should be between the hands, some folks ( I am one) like it a little closer towards the hand on the forearm. I like a muzzle heavy shotgun, helps to keep you from stopping your swing to fast. But if you don't have a lot of upper body strength, towards the hand on the pistol grip of the stock will be preferred, as it is closer to the body and will help you to control the weight, swing and recoil of the gun better in this position.

That's about it, other than the fits of the cheek piece so that it is comfortable and doesn't cut or smack the cheekbone, and lets you get a consistent cheek and should weld every time you mount the gun.

Lastly, shooting it at a patterning board will tell you how your point of aim relates to where the gun is going to throw its pattern, and of course, how it actually patterns with various loads of shot, chokes, etc.

If you consistently miss birds below them, the gun shoots low for you, and this must be corrected by stock alterations.
Conversely, shooting over the birds means the gun shoots high, this is easy to accommodate, just hold under the birds.

With my Browning Cynergy, I set it up to shoot high like a trap gun, I like my targets to always be completely visible as I said before, and the backstop behind them as well.

Now we’ll go a bit further and talk about some of the points on the stock and how their fit to your is important to accurate wing shooting.

For the following measurements, they are all taken from the bottom edge of a straight edge that is laid along the top of the vent rib if present, or the top of the barrel if no vent rib is installed.

Measure down from the bottom edge of the straightedge to the appropriate point on the stock to find the existing drop, and then figure out if it needs to come up or down based on what the shooter is seeing.

Stock Drop At The Comb



The stock’s drop at the comb where your cheek contacts it is important for a couple of reasons.
First of all, if it’s off, you are likely not going to enjoy shooting that gun, it’s going to be abusing your cheek!
Comb height is generally correct if the comb touches your cheek about midway between your upper lip and your cheek bone.
If it’s too low, and you have to raise your head to see that bead, guess what, you are going to get smacked in the face when the gun goes off.

I’ve seen shooters open a cut on their cheeks like this more than once, with a sharp comb edge that was too low for them as well as being too sharp.

Conversely, if the comb is too high and you have to squash your face down onto it to get that bead where you want it, while it won’t hurt as bad under recoil as if it were too low, it’s not going to be comfortable and your scores are going to suffer as well.

There is no standard factory drop at the comb distance that I know of for all guns, it varies with the length of pull, manufacturer, etc. but will be pretty much the same on all shotguns of the same make and model with the same stock.

In other words, for example, all standard, factory stocked Remington Model 870’s will have the same drop at the comb given that they all have a, say, 14.25 Length of Pull stock on them that has not been altered.

Stock drop at the comb is altered by removing material from the stock if it is too high, adding material if it is too low, installing an adjustable comb, etc. The adjustable comb is a good idea if more than one shooter, say, a husband and wife for example, will be using the gun.



Stock Drop At The Mid Point of The Stock Location

This one is usually pretty darn close to the drop at the leading edge of the comb, although some shooters will like it a bit higher, some a bit lower, and some want it to have a gentle radius.

All that comes from the shooter’s facial features, and you have to fit it to them carefully to make them happy.

All in all, you have to get the comb height right over its entire length if the shooter wants to hit the bird, since your eye becomes the rear sight of the shotgun, if the eye isn’t positioned in the right place ,and doesn’t come back to the same place with each and every mounting of the gun, you aren’t going to be able to consistently break birds.

Again, there is no standard factory drop at the mid point location distance that I know of for all guns, it varies with the length of pull, manufacturer, etc. but will be pretty much the same on all shotguns of the same make and model with the same stock.
In other words, for example, all standard, factory stocked Remington Model 870’s will have the same drop at the mid point location given that they all have a, say, 14.25 Length of Pull stock on them that has not been altered.

Stock drop at the mid point, just like at the comb, is altered by removing material from the stock if it is too high, adding material if it is too low, installing an adjustable comb, etc. Again, the adjustable comb is a good idea if more than one shooter, say, a husband and wife for example, will be using the gun.

Drop At The Heel

With most modern shotguns with factory stocks, the drop at the heel does have a somewhat standard distance measurement from most manufactures, and that runs right about 2.5 inches on standard stocks.

The heel of the stock is the top edge of the buttplate or recoil pad, that rounded surface there that should be beveled slightly to facilitate a smooth mount from the low ready position.

You don’t want it to hang up as the gun comes to your shoulder, and the bevel, along with a slightly slick recoil pad, helps with this.



Drop At The Toe

Again, with this one the current factory standard on modern guns seems to stay right around 5 to 5.5 inches or so from the top of the rib or barrel to the bottom of the toe.
The toe is that rounded edge at the bottom of the recoil pad or buttplate.
The drop here helps to determine where the stock’s center bearing point is located, and can affect how you see that front bead.

Once in a while that 5 to 5.5 drop isn’t enough, and the shooter will benefit from a bit more drop here.



Pitch Of The Stock
This is the angle at which the stock’s blank was cut, and the stock was shaped to.

The easiest way I know of to check it is to set the UNLOADED shotgun down on the floor on the butt, so that the heel and toe are making contact fully with the floor, and then lean the shotgun up against a (hopefully vertical!) wall with the receiver’s top just touching the wall.
Then measure the distance from the wall’s surface to the top of the barrel or vent rib if it has one.

Now days, a pitch distance of from 2 to 2.5 inches seems to be the norm.
English style stocks will often have a lot less, almost zero on some I have seen / worked on.

The pitch angle of the stock works with or against how the shooter’s body is built in determining how much felt recoil you feel. The angle affects this because it affects how far the gun is going to jump in an upward direction during the recoil impulse.

A pitch angle of 90 degrees is zero pitch, this means that the surface of the buttplate or recoil pad is at 90 degrees to the centerline of the bore of the gun.

Positive pitch is when the barrel is above that 90 degree line, and negative pitch is when the barrel is below it.

Fitting pitch to the shooter means setting the gun up so that the when the gun is mounted, the recoil pad contacts the shoulder evenly from heel to toe.

To change pitch we can either install angled shims at the junction of the stock and receiver, or cut the stock at that point to the desired angle, or change to an angled/tapered recoil pad.



Cant


Cant is the way you "twist" of the gun when you mount it. Twisting the gun results in your eye, which is the rear sight on a shotgun, not being in a straight line above the centerline of the bore. You can check for it.

The more you "cant" or “twist” the gun, the farther off that centerline your eye is, and the higher your eye is above the bore’s centerline, which makes effect of cant progressively worse.

To check this fit, you need another person to help you. With the gun UNLOADED, and checked to be as such by EVERYONE
PRESENT!! NO MISTAKES HERE!
you throw the gun to your shoulder with eyes closed as above, and have a second person at the muzzle look down the barrel with YOUR eyes still closed.

They are looking to see if you are shouldering the gun canted (twisted to one side or the other from a perfect vertical
orientation) , then, with you holding it still, they tell you to open your eyes.

They should see the bead(s) in perfect alignment
with the center of whichever eye is behind the barrel(s)/receiver. If not, you
will be making unconscious adjustments to it while trying to swing the gun on
the bird.

To correct for cant by altering the stock, the butt of the gun set to the shooters preferred angle while the bore and rib centerlines are perfectly vertical. About the only way to do this is easily is with adjustable hardware on the butt pad. Doing it by steaming and twisting the stock can be done, but it’s a trial and error process, and sometimes the stock cracks!


You can learn to not cant the gun, and this is a lot cheaper than having the stock modified if the reason for the cant is just
that you are not properly mounting the gun.

That’s the case I find about 90% of the time.
For the other 10%, the gun will have to be modified as I described above.

Cast

Cast comes in two flavors, Cast Off (right handed shooters) and Cast On (left handed shooters).

Cast is how the stock curves or bends from the wrist / receiver junction back to the buttplate, and it affects how the rear sight (the shooter’s eye) comes into line with the front bead.

A Right Handed shooter with a heavy face may need a lot of cast off, anywhere from 1/8” to as much as ½ “ of bend placed in the stock so that it resembles a backward facing letter “C”.
This lets the right eye get straight in behind the bead.

A left handed shooter may need Cast On, which bends the stock to make it look like the letter “C” for the same reason.

Shooters with thin faces may need little to no cast at all. Most standard factory shotguns today come with very little cast if any, and if there is any present, it will generally always be Cast Off for a right handed shooter.
Sorry lefties!

Casting a shotgun stock can be done by material removal in small cases , or for large amounts we steam and bend the stock.
Doing that in this direction, as apposed to doing it for Cant, rarely ever results in a broken or cracked stock if done correctly, assuming the manufacturer of the stock cut the blank with the grain orientated properly that is.

You can also add adjustable butt plates and get some cast that way as well.
Adding material can also correct cast when required.

OK, that’s about it for a more detailed look at Shotgun Stock fitting.

Any questions, you know where to find me!