Does not a double have to be regulated to converge at a certain point? If so until that distance is reached and after it will be off. Something to consider.

When I patterned the guns with TSS the patterns were all not to the point of aim. That is why I bought the lasers. When I dove hunt I try to take a different gun every day, and when I turkey hunt I don't want to be remembering this gun right barrel shoots high and to the left, this gun left barrel shoots low and to the right, etc. I believe Parkers mostly were patterned at forty if my memory serves me correctly?

My point is that if I make a small mistake in aiming/shooting, and the gun's pattern center is off by two feet already as one of the guns was at forty yards according to the laser, one will surely miss.

I recently sold a very nice Ithaca Classic Double 28 GA that for me shot low. The new owner reported it shooting perfectly for him.
Bob Jurewicz

Without legitimate sights, I'm not sure I understand how there can be a "universal" point of aim (one that would translate from shooter to shooter) for a given shotgun. The stock configuration is a major determining factor in where the gun shoots at whatever distance it was regulated for. Double shotguns are not meant to be aimed, but rather, pointed. Part of the difference in stock drops in older v. newer doubles has something to do with how shooters mounted guns at those different points in history (older shooters held their heads higher than more modern shooters). Add in different individual facial features (measurements) and it can get pretty complex.

I have some doubles that have a lot of drop. I have to consciously aim more than point them. I can't hit a flying bird worth a darn with them, but they work fine for squirrels and turkeys.

I've not had good luck with laser devices, but I'm sure mine were too inexpensive to have any sort of quality control.

I must admit I find this post confusing. The only time I've had issues with a double gun NOT shooting both barrels to the same point was when the barrels had been cut. My tests were all done "pointing" rather than aiming, though, so that's probably why I'm puzzled by all of this.

Jerry, as I read this the gun is held static and the laser is concentric with the bore at the muzzles. If that's correct then I question how your methodology translates to actually shooting said shotgun from the shoulder.

Your tests don't account for “barrel time” = milliseconds during which the muzzles rise while the shot travels down the bore. That begins at the instant of firing when the gun starts to recoil. Barrel time will vary with different velocities and thus the muzzle rises less or more before the shot emerges, depending on the shells being fired. And all that in turn affects the POI versus the "point of aim" just before firing.

Also, how about the torque/twisting effect when the gun is fired? Left barrel will have less sideways movement than right barrel (for a right shoulder shooter). Vice versa for left shoulder shooters. Again that will affect the POI.

The guns were placed in a Lead Sled both for the targets with TSS, and also to find the center of the bores on three different guns yesterday. I understand that mounting a gun of different dimensions changes how well one shoots a particular gun, and when one finds a gun that they just can't miss with, it is wise to shoot it exclusively. The old saying is to beware of the man who only has one gun. He knows how to shoot it.

But I think many are missing the point that what good is a gun that has the center of the bores on each barrel that is three feet apart at forty yards and they shoot that way, as the VH with .027 in each barrel indicated? The 20 gauge Sterlingworth that I took last year to turkey hunt did not pattern to the point of aim at forty yards, so I knew on that gun if I took a shot at that distance, I had to aim almost a foot to the left of a turkey's head to center the pattern. But I don't know that on each gun and they will have different pattern locations at this distance apparently. But the closer in one gets the difference in the centering will be less extreme.

Old turkey hunters will say how did I miss that bird, I had it right on him. Maybe this explains some of it as we trust the guns too much to be regulated. If one looks at the NRA American Hunter magazine they will show the pattern of a gun and show how many shots hit each quadrant. But often the point of aim is way away from the center of the pattern. Not so extreme on single barrel guns.

p.s. I do aim at turkeys and deer and really try not to point, which pointing causes me to say "How did I miss that bird?".

Since there seems to be some doubt about the lasers, I had to prove it to myself. I took the 20 SW that shot always to the right at 40 yards, and put the gun in the Lead Sled and inserted the laser. Sure enough the laser indicated it would shoot as it did, way off to the right. I also did the right modified barrel. Both were high but I would expect that to allow for the shot charge to drop at that distance. The laser was true in this case.

So my guess is these 20 gauge SW barrels are regulated to a shorter distance and the axis of the bores will cross perhaps at 30 yards. I can live with that because truly the 20 should be a 30 yard gun and I was stretching its capabilities with TSS. The ones I need to worry about and is why I cannot hit with them are perhaps those that are shooting as indicated by the lasers, low.

It may also explain why when I get a new double I can hit every clay bird with one barrel but with the same gun miss every bird with the other barrel, no matter at what distance I shoot them.

LEFT FULL 1ST PHOTO
RIGHT MOD 2ND PHOTO TURNED CCW FOR SOME UNKNOWN REASON

Jerry, do you know if the barrels or chokes were ever work on? I assume Parker regulated gun barrels as it bored the chokes and established patterns. When I visited Connecticut Shotgun, Tony G. took me through the "factory" and showed me all of the various processes. I saw the barrels being tested and was told that they were adjusted if they did not hit in the same spot when tested. The honing rods (my word, I don't know the technical terminology) were longer than the length of the barrels and run through from the breech to insure concentricity. The barrels would not move on beyond this point unless they were regulated. It's hard for me to believe that Parker would have done much differently.

This is perplexing to say the least.

I think we also should consider that the manufacturer, Parker, Fox, Lefever, etc., patterned these guns with a specific manufacturer of shot, powder, fibre wads, etc. and I think if our testing/patterning is to be considered relevant we must do our patterning with exactly the same components that were originally used by the manufacturer on a particular gun. And I know this is nearly impossible, so I think we can expect some varying POI's than what we hope to see.






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I have patterned alot of different sxs's without a laser and have only had one that did not center the pattern, I have no idea why you need a laser to pattern a shotgun.