Comb Movement And It's Effect On POI

[the spank]

In case you've ever wondered how much comb movement effects POI here is a couple pictures along with a with calculated values of your POI taken from the book "The Stock Fitters Bible".

Courtesy of Rollin Oswald, the author of "Stock Fitter's Bible"

The bottom photo is from a Microsoft Excel 2007 office spreadsheet which is available for download.

 

[Shibby!]

Known to a degree, but nice to put solid numbers to things I haven't bothered to compute.

Not that you need adjustable comb, but it shows the importance of gun fit.

 

[bdft]

It also shows how little you have to raise your head off the stock to miss the target completely.

 

[the spank]

It also shows how little you have to raise your head off the stock to miss the target completely.

You can be a long ways off with a small change.

 

[Beretta687EELL]

You always move the comb in the direction that you want to move the pattern in relation to the point of aim.

 

[beretta boy]

... and you should always verify by patterning when you make a change. Minimum of 5 patterns.

I've always worked on the theory of 1/16" moves it 1" @ 16 yards, using a fairly tight choke.

Rollin is a sort of "Gun Fit Guru" and is quite active on one of the US Shotgun sites. He's done a lot of fitting work and shot a ton of patterns to learn what he has.
Very pleasant & helpful ... spoken with him a number of times.

 

[davesaudio]

His book is great, understandable.