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Hello. I'm sure this has been neat to death already, but I don't see it... so please bear with me.

I have a gun with both an adjustable comb and rib. My thought was to put the rib on its highest position (at the muzzle end), adjustable the comb to the point the gun shoots flat, and then adjust the rib down to get whatever POI I wanted. But a friend of mine with much more experience than I have says that is wrong... that I need to adjust both together. I don't follow his logic. Can someone either explain or point me to a book/article that will explain it. Thanks.
 

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Putting the rib at its highest setting can definately create a odd look over the top of the rib when patterning your shotgun that would to me uncomfortable.

Many of us start with the rib at its middle setting adjust the comb up and start with a basic patterning session.
Many use Neil Winston's 13 yard method over a 40 yard method to get started.
 

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It would be way easier to set the rib on zero (usually 70/30 from the factory), put the comb where you want the sight picture, pattern, move rib as needed, move comb if needed to get the sight picture you want, pattern. Then you should be able to fine tune the POI with the rib, move the comb for picture.
 

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Discussion Starter · #5 ·
I am familiar with the 13 yard approach, and I understand your comment. Maybe I needed to explain better. Suppose I have my gun dialed in at the 16 yard line, and now want to shoot from farther back. My thought was to simply bring the rib down, but my friend is saying that both the rib and the comb should be adjusted. I don't understand the logic to that.
 

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I am familiar with the 13 yard approach, and I understand your comment. Maybe I needed to explain better. Suppose I have my gun dialed in at the 16 yard line, and now want to shoot from farther back. My thought was to simply bring the rib down, but my friend is saying that both the rib and the comb should be adjusted. I don't understand the logic to that.
The comb is your rear sight. Moving it up or down will move the poi up or down.

on most guns moving the rib just changes your sight picture and may move the poi slightly. The old style K80 unsingle barrels and maybe a few others are the exception to this.

Someone please correct me if I’m mistaken
 

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I am familiar with the 13 yard approach, and I understand your comment. Maybe I needed to explain better. Suppose I have my gun dialed in at the 16 yard line, and now want to shoot from farther back. My thought was to simply bring the rib down, but my friend is saying that both the rib and the comb should be adjusted. I don't understand the logic to that.
I wouldn't (and don't) touch the rib, just put washers under the comb till you're smoking handicaps.
 

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Perazzi MX2000 31.5/34 combo with a prosoft
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I am familiar with the 13 yard approach, and I understand your comment. Maybe I needed to explain better. Suppose I have my gun dialed in at the 16 yard line, and now want to shoot from farther back. My thought was to simply bring the rib down, but my friend is saying that both the rib and the comb should be adjusted. I don't understand the logic to that.
Technically you’re not wrong. And technically he isn’t either.

If you move the rib down, it will shoot higher, because you have to lift the end of the barrel to point the same.

BUT!
1) if you already have a figure 8, this will make your midbead cover your end bead.
2) if you aren’t stacked and have a gap, it will change your site picture.

To some degree, this defeats the purpose of adjustable ribs. To combat this, you should adjust the comb up about 1/8” for each 10% poi change down at the end of the barrel (varies my manufacturer and rib height, length, etc).
 

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Adjusting the POI can be done either with the front sight or comb.
The comb adjustment moves the POI the same way. Move comb up Poi moves up. Right for right etc.
The front sight it is opposite. Move sight down POI moves up.

If you can adjust the rear of the rib, Put the rib down, front and back. Adjust POI with the comb.
Bring the back of the rib up to get your Fig 8 sight picture or what ever sight picture you want. Having a Fig 8 makes the sight picture more precise than guessing that the space between the beads is correct, no matter what the actual POI is ie 60/40, 70/30, etc.

Jason
 

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If you aim your shotgun adjust your rib.
If your gun fits you,and hopefully it does. Adjust your comb to bust the birds, then if your sight picture isn't what you want, adjust the rib.
 

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Been through all this and it was a bummer until-----
I read that you always set your comb first to get your eye centered and just above rear of rib. This with the rib in the center. Then lastly adjust the rib for fine adjustments.

I had mine a bit too far out of alignment with the bore to such an extent that I had it just where i wanted it at 13yds (65/35) and thought I was done --- took a quick pattern at about 35 and found it at 100%.
Went on to realize the rib was adjusted so far off the bore alignment my pattern was gaining at distance---if that all makes sense.

If you can set your rib reasonable close to parallel the bore and then set the comb first you are going to be well satisfied and can adjust the rib that final amount to accomplish your goal.
 

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If your gun has a rib that adjusts both front and back by putting it in one notch or another, it’s what I call a teeter totter rib.You are putting it in the top notch in front so it MUST go in the bottom notch in the rear. 2nd notch from top in front, second from bottom in rear, etc etc. comb height determines POI on this type setup, all the rib adjustments do is give you the desired sight picture.
mid suggest putting the rib in a middle position, then adjust comb to give you a figure 8 sight picture. Shoot a few patterns and adjust comb up or down to get POI where you want it. Then readjust the rib to get your sight picture like you want.
 

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Suppose I have my gun dialed in at the 16 yard line, and now want to shoot from farther back. My thought was to simply bring the rib down,
Right off the bat, Your moving the rib the wrong way!!! You want to flatten your rib the farther back you go. Not raise your POI when you move farther back. You will be shooting over all your targets if you do this!!!

To make this easy for you. What POI do you want to be shooting???

Now simply set your rib to your gun manufacturers settings for the POI you want. Whatever notch(s) front to back, they tell you to set your rib too. Now simply move the comb around to get your perfect figure 8 with both beads. You are now done. The whole idea of having a adj. rib is so that you do not have to create space between your beads to raise your POI!!!! The bigger the space between your beads, the bigger your chance you have moving your eye up and down when you mount the gun and never even know your doing it!!!! If you like a 1/4 space between your beads. It will be easy to mount your gun one time with a 3/16 space on your next shot, only to have a 5/16 space on the following shot!!! You are moving your eye around 1/8 of a inch and your not even aware you are doing it. You can do this all day long and never wonder why you can't get out of B or C class!!!! If you keep your beads tight. You know right away if your mounting your gun wrong!!! You will only one bead, or you will have space between your beads. Both are wrong. You want to fine tune your gun mounts, and check your bead space on every gun mount. Leo did this. Its hard to argue with his logic!!!! I'm no Leo, but most times I drop a target its because, I got lazy on a gun mount, (had the stock too low) and had too much space between the beads and forgot to check!!! All shooters will miss a target at times. What you don't want is to give away targets because of something you did that was stupid and could have been avoided.

If you don't want to follow this logic? Then why buy a shotgun for thousands of dollars more money to have a adj. rib???? You can just shoot your old fixed rib shotgun with a 1/4 space between the beads!!!

I too say: start with a 70/30 POI. This setting works best with most shooters. Good Luck to Ya. and don't forget to break em all Jeff
 

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I am familiar with the 13 yard approach, and I understand your comment. Maybe I needed to explain better. Suppose I have my gun dialed in at the 16 yard line, and now want to shoot from farther back. My thought was to simply bring the rib down, but my friend is saying that both the rib and the comb should be adjusted. I don't understand the logic to that.
Whenever making a change only one thing should be done at a time. Control the variables to understand the outcome. OR add a couple different weight and speed shells to completely confound the results.
 

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Hello. I'm sure this has been neat to death already, but I don't see it... so please bear with me.

I have a gun with both an adjustable comb and rib. My thought was to put the rib on its highest position (at the muzzle end), adjustable the comb to the point the gun shoots flat, and then adjust the rib down to get whatever POI I wanted. But a friend of mine with much more experience than I have says that is wrong... that I need to adjust both together. I don't follow his logic. Can someone either explain or point me to a book/article that will explain it. Thanks.
I've set up a 725 with an adjustable rib (50% - 100%) and adjustable comb. I set the comb where I wanted it for a comfortable mount, then adjusted the rib until it was shooting where I looked. Next, I set up an MX-15 that shoots considerably higher and ended up raising the front of the rib to the top and dropping the comb until it shot where I was looking. Both methods woked fine, so I suspect as long as the gun shoots where you look, it doesn't much matter how you got there.
 

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Simplistic explanation:

Adjust comb for POI
Adjust rib for "sight picture"

The reason you move both (comb and rib) in sequence is to maintain the sight picture (figure 8) while moving the POI.

If you only move the comb, your POI will change but you will either have over stacked beads or have barrel showing in between the beads. Neither of these are necessarily wrong but go against the norm for trapshooting.

If you move only the rib, your sight picture will change but your POI will remain about the same.
 
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