Question about gun fit

[Spinner]

Lots of folks with lots of experience say that gun fit is very, very important. So, I guess its important to know if a gun doesn't fit very well and just to clarify in my mind let me try to run through a few possible "sight pictures" and see if they correspond with the wisdom of the experienced.

Now, I know you're not supposed to look at the bead, rib, barrel(s) or anything other than the bird, but for the sake of this enquiry about gun fit I'm going to talk about ribs and beads.

Please correct me if I'm wrong. The following is my understanding of checking gun fit but I'm very keen to know if I need correction.

OK, so to determine gun fit you need to:

1) close your eyes
2) mount the shotgun to your shoulder 4 times
3) open your eyes and check the "sight picture"

The butt of the shotgun should be sitting comfortably in the "pocket" formed between the deltoid and pectoralis major muscles (sitting between chest and shoulder muscles).

Your face should be vertical

Your eyes should be horizontal

If you find you are looking directly down the rib then the gun has the correct cast for you. If you're looking across the rib then the gun has either too much or to little cast on/off or the cheek piece is too full or not full enough.

The toe of the stock shouldn't be digging in anywhere

If you find the thumb of your trigger hand approx 1-2" in front of your nose, the length of pull is about right.

OK .... now for the tricky part. How much rib should you be able to see?

I have 2 shotguns; a Win 1400 and a Bettinsoli O/U. The Win 1400 has a ramp at the rear of the rib. When I mount this shotgun I see the ramp and I'm looking directly down the rib at the bead. When I mount the Bettinsoli, I'm looking down onto the rib slightly (ends up with very similar "sight picture" .... same amount of rib visible with a bead "floating" on top).

From the discussion I've seen about mid rib beads and the "figure 8" presentation of the two beads, I'm guessing that the proper set up is to be looking down onto the rib slightly so that the front bead floats slightly above the mid bead. If my Win 1400 had a mid bead I would not get a "figure 8" .... but I probably would with the Bettinsoli.

OK, so from this crude description, which shotgun fits me better .... which is the proper "sight picture"?

Spinner

 

[sm]

Hey Spinner,

I'd say you have a great understanding of gun fit. From your description I would say your Bettinsoli O/U fits you best.

I would gather to say a pc of moleskin applied to the stock would be just enough to raise the comb on the 1400 to match the O/U.

What happens is if the shooter has to raise the head in order to shoot the shot will be high. One should in theory never miss by shooting over the bird/clay. If the sight picture is like the Betinsoli Spinner you should be able to keep the muzzle just below the target ( a thin line of daylight) and break it / fell it.

If the clay/bird/target is falling it is always better to "drop down" and keep the target in view with the muzzle below. If the target gets obscured by muzzle and you lose sight...you will miss. Head comes off stock to find it and one will not shoot where looking.

Exceptions:
For LEO, and such wearing a vest the LOP needs to be such that the total LOP takes this added thickeness into consideration. Shorter LOP in such cases

AS always adapt the tool to the task.

 

[kudu]

Let's throw this into the mix, trap guns are designed to shoot higher than field guns, mine throws a 70-30 pattern. I can see a lot of rib between the beads which is just as it should be for trap. My Beretta skeet gun throws about a 60-40 pattern so I can float the bird a few inches and see it at all times while tracking it. This is how I prefer it. A host of my other shotguns shoot 50-50 and I have to push through the targets to break them. I once had a Ruger red label sporting clay gun that shot about a 35-65, it was a pain to shoot, but did well on skeet doubles as the second bird was always dropping.

The only sure way to know where your gun shoots verticaly is the pattern board. As long as you are looking straight down the rib when fitted you can usually adjust verticaly for POI.

A lot depends on what use you want your gun to perform.

 

[sm]

kudu

Thanks, for your input. I was trying to figure out how to explain the gun fit in regard to different "tasks" - skeet, trap, S/C, hunting , and Serious Situations.

This gun fit is easier to show someone than it is to put into words.

 

[Spinner]

Interesting

From the limited amount of patterning I've done the 1400 shoots with a slightly bottom heavy pattern ..... puts the majority of the shot a little below the point of aim. The O/U puts the majority of the shot a little above the point of aim at 40 yards.

I guess this is primarily due to the stock configurations (now why didn't I think of that???).

It never occurred to me that I should have a pattern slightly above the point of aim so I could float the clay on top of the barrel ..... I just always figured I'd have to squeeze the trigger as the bead covered the clay. See, now that's what you get with a rifle guy trying to teach himself shotgunning!

I think I'll sit down with the 1400 and some aluminum foil and make some shims and see how that affects fit.

Edited to add: There are those unkind souls who would ask the point of having the 1400 fit me as gun fit isn't essential when your gun is gonna jam anyway. hehehehe

Spinner

 

[45auto]

For rifle shooters, I would knock off both beads...just because they like to look at them.

Good thread. Stock fit is a bit of science and magic.

As mentioned, the only way to really test the POI is on paper. Rib confiqurations, bbl hangers, boring of chokes can effect the POI...along with the stock of course. Assuming the manufacturer does it properly of course. Many O/U's will pattern differently with each bbl, which may be useful in some sports.

IMHO, regardless of the beads, I think a 60/40 pattern is a pretty good all around. Again, IMHO, you should be able to "blot" out the target and "float" the target and have a good break. I believe going to 70/30 or 80/20 trap type of POI is doable, but you really have to be "concious" about "floating" targets.