doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Stock Dimensions and POI

I have a couple of doubles that shoot to a much different POI at 16 yards. Here are the stock measurements and POI. I am looking for which dimension is the culprit.

#1 POI is 10% high and centered at POA
Drop at Comb 1 5/8
Drop at face 1 15/16
Drop at Heel 2 5/16
Cast Off at Comb 1/8
Cast Off at Face 3/16
Cast Off at Heel 1/4
Cast Off at Toe 3/8
LOP 14 3/4
Pitch 2
Degrees 4

#2 POI is 5" low and left
Drop at Comb 1 7/16
Drop at face 1 7/8
Drop at Heel 2 3/8
Cast Off at Comb 1/16
Cast Off at Face 1/8
Cast Off at Heel 1/4
Cast Off at Toe 3/8
LOP 14 3/4
Pitch 2 1/2
Degrees 5


Both stocks were measured by a professional fiiter, but I did not get a chance to speak about the differences.

Thanks.

Jim

Well,
Gun 1 seems to be the closer of the two on point of impact. Centered would suggest that cast is where it needs to be. And only 10% high is not that much.

Gun two results suggest the stock is about 1/8� low in the stock and cast needs adjusting. However, the measured dimensions do not seem to be jiving with those conclusions. ???

As a stocker, I see several questions to ask. Are the makers the same? In my career, I have found the differences in maker receiver sizes make a difference even when using the same dimensions from another gun mfg'er. Are the stocks set up the same with the same kind of hardware (solid butt, recoil plate, recoil pad). Are the rib types the same? How is the regulation of the barrels (use a laser pointer inside the bores to determine POI at 30 ft.)?

I have found 1/16" in comb height makes only marginal differences in the POI for most shooters ( there are exceptions to every theory). The 1/2" difference in Pitch may affect POI depending on your mounting process and your style of shooting. The 1/16" cast of the comb difference is telling, as your second gun patterns left. As Brian said...it needs more cast off.

Laser dot is 2 1/2 inches high and 1 1/4 inch left on gun #2. Same makers built two years apart but #1 has original stock with original thin horn butt plate. #2 was restocked and has no butt plate.

Jim

Are the comb profiles the same?

Regulation is high but shoots low. Regulation left and shoots left. As Dale Tate once told me...bend the barrels as needed. Sounds simple...but it works! Funniest thing in the world to see a grown man sitting on a set of double barrels during a shoot to change the POI. Of course, he was not doing it from a lack of knowledge. He had Purdey's of London training!

Pitch is greater on gun #2. POI is different. Sounds like the restock is your culprit. Comb thickness the same? Send the gun to a competent stock bender to have your gun altered to bring both guns into same standards of your choice. There are many here to choose from. Call, Ask, Decide.

Comb on #2 is thicker. Would that explain the pattern low as well as left?

Jim

Your face is the back sight, the thicker comb will at least move your face left. You move rear sight the direction you want to shift the group, or center of the pattern.

Yep. The left makes sense. How about the low?

Jim

No, the thicker comb does not explain the low. I'd play with wedge spacers under the buttplate to vary pitch and see what that does to elevation. Notice what Dennis said earlier about pitch and mounting style.

Are you "squirrel aiming" the gun, or throwing it up and shooting quickly?

SRH