Yes that is correct.
Raising the front bead has the same affect as lowering the comb and vice versa.

Its All Good
West

 

From a base line of Zero.....If you raised only your comb 1/4" and like the POI but now see too much rib, an option is to lower your front bead 1/8" and raise the comb 1/8" from the base line of Zero, and you'll have that same end result POI.

In both cases you've raised your rear sight (your eye) 1/4" higher than Zero.

 

You might wanna take it to the pattern board you may be surprised. That will answer your question.

 

Raising (or lowering) your comb does raise/lower your POI, no "supposedly" about it. Adjusting the rib also adjusts the POI up or down, but more of a fine-tuning to me. I use a low-pad/high comb because I have a long neck and need the distance between toe and comb. I use a high rib (adjusted for me) in conjunction with this to keep the POI where I want it, which is probably about 80/20 on all my trap guns. Basically, once I get the stock where it is comfortable for me, I adjust the rib/front bead to get the POI I am after. "Mr Average" 5'10" chode-neck can shoot any stock field gun comfortably, and really doesn't need this. When I see short thick guys shooting high-rib guns I assume it is for fashion.

 

Shoot it at your handicap yardage adjusted to shoot 50/50. Raise it up every box until you hit the targets the hardest. There was a really big, big dog who didn't believe in shooting on a pattern board. Probably because he figured it'd mess some people's minds up. No matter what the clubhouse wisdom might say, there is usually
always a better way.

 

I would try to adjust the rib to the pattern you want then raise the comb to get the beads figure 8.

 

With all due respect sir, this makes no sense. If you adjust your rib to the POI you want, then any adjustment to comb height will throw that point off. And the figure 8 is just a beginner's guideline. If you had already adjusted your front bead/rib so that the gun hit where you wanted (say, 12" high at 35 yards) then it makes no difference where your mid bead is. I don't have a mid bead on my 3200 anymore, and don't miss it a bit. But I am confident in the fit/mount. When it was new to me and I was fitting it I needed that bead to make sure I was pointing true.

 

????

 

You set the comb to the pattern you want them adjust the rib to the POI

 

No, I set the POI 1st, rib all the way down in front, all the way up in the back, that way I know for a fact that the gun is already shooting " 100 % or a pattern high", then set the comb height to make the gun shoot where I'm looking. In my case I have to raise the comb higher, in fact enough so that I see the whole rib from the ramp on. With it set like this I've also learned a little bit about shooting off the end of the barrel. What I mean is I've pretty much learned to briefly look at my center bead, then get my main focus out in the target area, looking mostly at the bead on the end of the barrel. Call for the target, don't move anything until the target clears the barrel, just go to the target & break it. I found out early on that I could not shoot the gun using a stacked figure 8 sight picture & 100 % POI , I would shoot about a 1' under my targets. I've learned to trust my gun mount to the point of it becoming instinct, & feeling the same each time I shoot the gun. This way I know I'm looking right down the middle of my barrel trying hard to maintain my focus out in the target area. Gun fit is also super important, your gun has to fit you properly. I'm not claiming to be a expert or anything of the sort ,just what works for me when I do what I'm supposed to do & shoot a decent score. Ed

 

ED, that's a very clear description of what you did but it does bring up a couple of questions:

You wrote "No, I set the POI 1st, rib all the way down in front, all the way up in the back, that way I know for a fact that the gun is already shooting " 100 % or a pattern high",..."

and many of us probably wonder two things:

1. How do you know "for a fact" that the gun was set up to shoot 100% high?

2. What do you think "100% high" means? I ask that because there was a recent thread here which went on and on and apparently only Tech Writer Jeff could define the percent system at all; everyone else was just saying the words with no idea what it meant.

Also, how did your adviser learn that you were shooting 1' under the birds?

Understand, I'm not arguing against your findings, just wondering how you came to your conclusions.

Yours in Sport,

Neil

 

ED, that's a very clear description of what you did but it does bring up a couple of questions:

You wrote "No, I set the POI 1st, rib all the way down in front, all the way up in the back, that way I know for a fact that the gun is already shooting " 100 % or a pattern high",..."

and many of us probably wonder two things:

1. How do you know "for a fact" that the gun was set up to shoot 100% high?

2. What do you think "100% high" means? I ask that because there was a recent thread here which went on and on and apparently only Tech Writer Jeff could define the percent system at all; everyone else was just saying the words with no idea what it meant.

Also, how did your adviser learn that you were shooting 1' under the birds?

Understand, I'm not arguing against your findings, just wondering ow you came to your conclusions.

Yours in Sport,

Neil

You can see the difference in POI when you pattern the gun at 10 yards, also you can see when you shoot the target where you are shooting high, low. When I say the gun is shooting 100 % high, I mean the gun is shooting a full pattern high, 15 inches above where you are looking. Perrazi also tell's you that you can get the gun to shoot a full pattern high if you set the gun up with the rib all the way down in front & all the way up in the back, they (Perrazi) also tell's you that the gun with the rib set all the way up in the front & back will shoot 50/50. It really helps when you have a all american standing right behind you when you shoot your straight away targets from P3. I'm pretty sure that the Mx 15 Rib is built so that when you change your rib up or down each notch that you move the rib up or down is equal to changing the POI by 10 %. The Mx 15 rib has 6 notch's at the Front & Back. I can't say for sure what the other guns Perrazi makes with adjustable ribs shoot as some of them have 4 notch's & some have 5 notch's. I haven't shot the other models Perrazi makes, don't get me wrong , I've only shot the Mx 15. Like I said earlier this is what works for me when I set my gun up. Ed

 

Thanks for the reply, Ed. I'm still not sure we are on the same page, though.

When you test the POI of your gun at 10 yards, where is the big hole in relation to the aim point you used? How many shots did you take?

and how "can (you) see when you shoot the target where you are shooting high, low.?"

The thing is you are telling us that your gun shot way high when you set it up using Peruzzi's diagram and then you needed to raise the POI by another six inches, more or less. That sure sounds like a lot.

Neil

 

Thanks for the reply, Ed. I'm still not sure we are on the same page, though.

When you test the POI of your gun at 10 yards, where is the big hole in relation to the aim point you used? How many shots did you take?

and how "can (you) see when you shoot the target where you are shooting high, low.?"

The thing is you are telling us that your gun shot way high when you set it up using Peruzzi's diagram and then you needed to raise the POI by another six inches, more or less. That sure sounds like a lot.

Neil

When I shot the gun at 10 yards the pol was 4 1/2 inches to 5 inches above my Point of Aim, I shot 3 rounds to verify this. You can & tell if you are high or low by the way the target breaks, if it's shooting a little low look at which way the bigger pieces go when the target breaks, if you are shooting high pieces will go down, if you are shooting low the pieces will go up. Next I never said I was raising the POI up, what I'm doing is changing where I look by moving the stock up or down, I'm trying to make the gun shoot where I look, in my case I have to raise the stock & I keep raising the stock until I'm breaking the targets in the middle if the pieces are all pretty equal, not going up or down then you are pretty much in the middle of the target. I know of several top shooters who shot a gun that shoots over a pattern high, Dave Zanotti, Ron Alcoriza, Ray Stafford, Phil Kiner & many,many others, It doesn't matter if it's a lot or not you have to make the gun shoot where you look, if you don't do this you are just wasting your time & money.. Where did you get the 6 inch figure when you said that seemed like a lot, you where not there with me when I raised my stock up after I found out I could not shoot the gun with a figure 8 sight picture, you have to try & really focus on the target to see it break just like you do if you hit a target or not,I think if you are not looking at the target with a lot of focus from begining to end you are probably not seeing the target real well, how many times have you just broken a piece of the target & seen that it was in fact a dead target, well to me the same thing apply's , here's something else to think about, I found out you can smoke a target at 16 yds with the top ,bottom or r & l sides of your pattern & still not have a proper POI , there again you want to be dead center on every target if you can, but we all know you can't do this 100 time you shoot. Ed

 

OK, Ed, I both understand and agree with your POI test at 10 yards; the gun probably did shoot very high at singles distances when set up by the Peruzzi book. You just have to check to make sure, that's all, and you did.

You wrote "Next I never said I was raising the POI up, what I'm doing is changing where I look by moving the stock up or down."

Well, that's OK too though I generally think the effect of moving the stock up is that the POI is raised. But I do see that was not your intent.

"Where did you get the 6 inch figure when you said that seemed like a lot...?"

Here's how I got that 6-inch figure.

We will start by estimating the distance the POI is raised at 40 yards by moving the comb N inches.

Let's say the distance from your eye to the front bead is 42 inches, 3.5 feet. (Many people use the barrel length for this calculation, but I think bead-to-eye is right, a view supported in the POI Calculator thread at the top of this section.)

and the distance to a 40-target is 36"x40 = 1440 inches.

The ratio of movement at the gun compared to at the 40-yard bird is 42:1440 or 34 to 1. So a comb rise will result in a POI rise 34 times the magnitude of the comb change. A 1/4 inch change (up) will raise the POI at the 40-yard bird by 0.25 x 34 = 8.6 inches. But you are shooting singles so it won't rise that much. Let's take 32 yards as a singles distance, multiply 8.6 times 32/40 = 6.8 inches but many take their singles closer than 32 yards so I estimated 6 inches but if you prefer 7 inches I'll not disagree.

I thought you might be "reading the breaks" to find out which way to move your comb and ended up with a rise of 1/4 inch. You substantiated that with "I keep raising the stock until I'm breaking the targets in the middle if the pieces are all pretty equal, not going up or down then you are pretty much in the middle of the target."

The problem with that is that "reading the breaks" an illusion. It certainly seems like shot centered below the bird should move the pieces up, centered above the bird should move the pieces down, but what's just wrong; that's not what really happens. You haven't been here long, but Ron Baker, others friends, and I spent a lot of 2011 and 2012 making videos of target breaks and the shot-placement that led to them and demonstrated that the popular idea, "reading breaks for information about where the center of the pattern is" is wrong. Targets break the way they do becasue they have linear and rotational inertia and that's the whole story. It has nothing at all to do with where the shot that missed them was; how could it?

Here, for example, is a series of breaks that occurred when I raised the shot-cloud stepwise from below the bird to above it. Minus 4 (on the lower right of the video) is far below the bird; zero is on it, plus 4 is far above it. As you will see, there is no reliable difference in the contrasting breaks: minus 4/plus 4, minus 3/plus 3 and so on. In all cases, the pieces mostly go up, the big pieces to the right, the small pieces to the left.

TBF_rising_POA breaks

Here's another test of low-recoil AA's. All the shots are over the bird as ou can clearly see but there is no evidence of the "pieces going down" rather than up.

See what you think.

nodomesbroken

I'll bet your POI is right for your if you are smoking the targets; you might want to go back to 10 yards to document it in case you lose confidence in it, want to change something and want to have a known system to geo back to if it doesn't work, or just want a successful baseline from which to adjust other guns you may buy.

Yours in Sport,

Neil

 

If your rib is adjustable front and back, plus you have and adjustable comb.

I would adjust the rib down front and back. Adjust the comb to get the right POI. Then lift the back of the rib to get a Fig 8, NOT touching the front of the rib adjustment.

It is nice to see a Fig 8 beads. Then you know that your mount is perfect. Rather than seeing part of the rib and guessing the space is right.

When you document where the gun is shooting, do it from a Bench Rest, 13 yards, shoot it like a rifle aim with the bead and squeeze the trigger. 2 shots is enough if they hit in the same place.

Jason