Guns with POI adjustments

[MJJ]

Apparently putting wedges in your shoes also makes a difference, as it alters the angle of heel. So i am told.  

 

[Mutley]

When you shoot, your eyes, the barrels and the target make a triangle.

I have yet to see a clamped gun in a competition, of course the impact point cant alter on a clamped weapon, might as well throw the stock in the bin on that theory.

The gun is in your shoulder, the comb height alters how far up or down in your shoulder the gun sits, as you cant stretch your neck, unless you are having brass rings added.

The target is moving but is in relativley the same place regardless of comb height, so by altering the angle of the gun in your shoulder, it alters the angle the muzzle is at.

So the poi is different to before you raised or lowered the comb.

Arguing with a clamped stationary gun is not the same as the angle created between the eye the barrel and the target, the only time to clamp a gun and use a laser system is to set up a camera system, so its looking were you are pointing.

 

[ips]

So ! If my Krieghoff is shooting high , I lower the comb height and it then shoots lower .

Have I altered the point of aim and / or the point of impact?  

you have altered poi, because your poa remained the same (presumably) the other option would be too accept the kriegoff shoots a high poi and shoot under everything, in other words adapting "your poa"

 

[AW13]

Hmmm

Does the shooter adapt to the tool or do you adapt the tool to fit the shooter.?

 

[ips]

Hmmm

Does the shooter adapt to the tool or do you adapt the tool to fit the shooter.?

either can work. You soon learn were your gun shoots which is why I don't concern myself too much about comb height (within parameters of course)

when many of us started in the days when guns were fixed very few had guns fitted you picked one summat like and learned to shoot it. Worst thing I ever did was getting involved with adjustment. Now none of my guns have multi or adj anything.

 

[Hamster]

When you shoot, your eyes, the barrels and the target make a triangle.

I have yet to see a clamped gun in a competition, of course the impact point cant alter on a clamped weapon, might as well throw the stock in the bin on that theory.

The gun is in your shoulder, the comb height alters how far up or down in your shoulder the gun sits, as you cant stretch your neck, unless you are having brass rings added.

The target is moving but is in relativley the same place regardless of comb height, so by altering the angle of the gun in your shoulder, it alters the angle the muzzle is at.

So the poi is different to before you raised or lowered the comb.

Arguing with a clamped stationary gun is not the same as the angle created between the eye the barrel and the target, the only time to clamp a gun and use a laser system is to set up a camera system, so its looking were you are pointing.

No need for clamps as I already offered the alternative of laying the gun down on something as indeed suspending it from strings in mid air, the results will be the same, the POI will NOT alter in and of the movements (or the complete absence) of the comb. 

I am surprised that you should say something like : the comb height alters how far up or down in your shoulder the gun sits because in theory at least that must not be allowed to happen as it will lead to possibly more complications. If altering where the gun sits in the shoulder had a profound affect in POI then a Jones adjuster could be employed to do the same thing as barrel hanger, which of course it doesn't/won't.

Raising the comb will by definition push the cheek up therefore giving a different view. 

I have given perfectly simple (and provable) definitions and reasons of what, where and why, if people insist on calling the earth flat then I'm fine with that too. 

 

[Mutley]

.

Raising the comb will by definition push the cheek up therefore giving a different view. 

Yes it alters what you see, but I cant lift my comb and push my cheek up unless I move my head position on the stock and grind my cheekbone out a bit, it may be possible to lift a comb and not alter anything if you have jowels like The dog on the tv add's, but on most people it will move the butt slightly lower in the shoulder unless you are happy having your head wherever it lands on the stock.

I have just lowered the comb on my Gamba, its not adjustable so it was a permenant fix. I was losing the odd low target coming out under the gun, so dropped the comb to a more normal 30-45 , this has altered the POI by approx 5" at 40 yards, all done on the plate, it has also raised the butt by 3-4mm in my shoulder, How do I know? becuase its just touching my collar bone now ( Im on a high dose of warfarin so bruise easily, so this is noticabale).  My head is always constant, right at the nose of the stock with my nose touching my thumb.

From sitting just under the target, I am now into the centre to get a guaranteed kill, so if altering the comb makes no difference why does my gun now shoot lower and sit higher in my shoulder pocket?

 

[ips]

cant argue with a professional stock maker / fitter ?

 

[SIMON-B]

Will an extra bacon butty before a shoot change my poa/poi or just the poc (point of clampage) of my belt.

Sent from my GT-I9505 using Tapatalk

 

[Hamster]

Yes it alters what you see, but I cant lift my comb and push my cheek up unless I move my head position on the stock and grind my cheekbone out a bit, it may be possible to lift a comb and not alter anything if you have jowels like The dog on the tv add's, but on most people it will move the butt slightly lower in the shoulder unless you are happy having your head wherever it lands on the stock.

I have just lowered the comb on my Gamba, its not adjustable so it was a permenant fix. I was losing the odd low target coming out under the gun, so dropped the comb to a more normal 30-45 , this has altered the POI by approx 5" at 40 yards, all done on the plate, it has also raised the butt by 3-4mm in my shoulder, How do I know? becuase its just touching my collar bone now ( Im on a high dose of warfarin so bruise easily, so this is noticabale).  My head is always constant, right at the nose of the stock with my nose touching my thumb.

From sitting just under the target, I am now into the centre to get a guaranteed kill, so if altering the comb makes no difference why does my gun now shoot lower and sit higher in my shoulder pocket?

It has altered the perception by 5", not the same thing as physically raising the POI by mechanical means such as a barrel hanger.

I never said raising the comb makes no difference, Trap stocks transformed my own game years ago. 

 

[Dog Tyred]

I must say I was slightly surprised by the 'lowers the stock in the shoulder' comment.

Surely maintaining stock position is vital to consistent gun mount. As for not being able to raise one's eyes, head, etc. Well the last time I mounted a gun I had to lower my head onto the stock so there is clearly some leaway to raise it slightly....or a lot.

Last time I looked at a double trap shooter (with massively high combs) none of them had neck rings fitted and none of them hand the butt in their armpit! I also know a couple of shooters who have recently bought high rib guns to relieve neck strain by lifting their heads a little.

I'm out of this one now as I obviously know nothing about this.

DT

 

[Hamster]

cant argue with a professional stock maker / fitter ?

Depends, I can name at least two World champions who years ago wrote articles about shot strings which have now well and truly been blown away as myth. 

Don't also forget many people have professionally built guns ( think Perazzi experience  :smile:  ) leaving everything in the hands of people who know who get rid soon after. 

I am not disrespecting Mutley, merely highlighting he is confusing POI and POA. 

 

[Mutley]

Hamster, I do not disrepsect your view, but if you have or can get your hands on Renato Lamera's books, have a look at the function of the comb in the 2010 book.

I respect Lamera's view point as he coaches some of the worlds best and is amazing to see his style and confidence, all his shooting is with triangulation.

His theory is that a slow shooter (we are talking OT) should have a higher comb so they can steadily pull to the target and shoot it whilst seeing a percieved gap between gun and target, whereas a fast shooter should have a flatter gun so they can rip into the target without fear of riding over it.

The Perazzi experience as you mention has spoiled more shooters than I dont know what, having been on numerous occasions, they will push you towards higher combs than we English are used to, then you are forced into a static pattern system where the gun is as you said clamped basically into a padded post, you are just pointing the bead at a light. But if you go knowing what you want and also insist you want to shoot your new gun on the range you get a totally different beast.  

A little knowledge is dangerous in some hands, but its better than none when getting a stock made....

 

[Westward]

Everyone in this thread (and the other one) is right... Sort of. The disagreements are there because POI takes three forms. One way to test POI, which loads of Americans obsess about, is to hold the gun down on a bench rest and aim it flat along the rib at the target mark on the pattern plate. Since most guns have a slightly sloping top rib, chances are more pellets will be above the line than below. This establishes where the gun shoots and comb height is irrelevant because the eye is held  level with the rib.

Another test is with a normal shoulder mount and shot like a rifle with the bead aimed at the target. We can all see that in this situation raising the comb raises the POI and raising the rib lowers it.

The argument exists because no one shoots a shotgun at real moving targets using either of the above methods - or at least not in sporting clays. What we do (or should do) is concentrate on the sight picture of the target without focussing on any part of the gun and point the muzzles to where we want the shot cloud to go. All that's needed to do this is to have the line of sight above the rib and whilst there may well be an ideal comb height for comfort and smoothness, comb height (within reason) does not alter the POI of a pointed gun. You can demonstrate this by pointing with a finger at some distant object, then glance back at your finger. It's 100:1 that your finger will be below the line of sight. What's more, the actual amount below the eye doesn't particularly affect how accurately you can point your finger.

 

[Wonko the Sane]

Overall I would say that this thread rates a Silver OMG!!!  on the WTF? Scale

 

[westley]

Apparently putting wedges in your shoes also makes a difference, as it alters the angle of heel. So i am told.  

If we are talking 'K' guns, they will have no wedges left  !