doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Inherent inaccuracy of a SXS-How Much?

If this is true, very interesting!

It is quite obvious upon simply looking at a set of SxS bbls that they in fact do converge toward the muzzles. Upon firing them for point of aim it also becomes readily apparent they do not cross fire to the extent the bore convergence would indicate if the in fact hit where they pointed prior to firing.

Along the same line if you check on most any pistol/revolver larger than a .22 short yo will note the bbl is pointed below the sight line. Muzzle rise moves the bore line above the sight line prior to the bullet's exit.

Mike,
since the barrels converge at something like .010 per inch or more (don't quote me as I haven't checked in a while on a 12g), wouldn't the amount of POI difference, at other than the regulated distance, be based on the lateral displacement when the payload left the muzzle, from the muzzle from the sighting line (eyeball/bead) at trigger fall? The same would be true of the vertical plane as well?

Sorry Chuck, your question went over my head.

I am saying that if the if the barrel centerlines are .85" apart and the POIs converge at 40 yards the POIs will .425" apart (horizontal plane) at 20 yards.

I repeat that this difference is more than I can hold the gun to or even see.

Best,

Mike

Mike;
This would be true if the bbls were static as the shot traveled down the bbls. That however is not the case. An extension of the bore C/L's do not converge @ 40yds, but much, much closer to the muzzles than that. Each bbl thus has to "Whip Out" for them to perfectly center at 40 yds. The spread @ 20 yds would thus be greater than indicated by just the muzzle seperation of the two bbls. It is though still nothing to get up on one's tricycle about & of no practical consequence.
As I recall without getting my L C Smith Plans & Specifications book out which gives bbl convergence for their guns at 40 yds the bore axises will have crossed & be spread by about 15-16 inches. The axis of the two bores converge at a rate of around .011" per inch. When I first acquired this book I checked the seperation of some of my Lefevers at both breech & muzzle & for this point they could have been built to the Smith specs.

Note how this is not trivial information at all. It's pretty basic to understanding the dynamics of a SxS.

I thought this was well known, but apparently not.

Thank-you as always Miller.

I don't think it really matters inre. to double vs single barrel accuracy unless you are talking about a shotgun used for deer hunting with slugs. Although I killed my 1st deer with a Fox 12 ga double I would certainly NOT recommend this as a good choice.
I've alway shot with both eyes open and tracked the target either a live bird or clay and IMO have only been remotely aware of the fact that I'm swinging a gun either a single or double. The "image" I have is there's something swinging in my hands that is tracking the target just like my eyes and when everything "looks" right I'll pull the trigger.
Jim

There is no inherent inaccuracy! What's the matter with you? Have you ever shot a SxS before?
There's the old saying that "there are no stupid questions" but in your case I'm not too sure.

With A Special Salute to Mr. Moody:
Bravo! Let them count the angels on the head of a pin. It's all fun to read. Mostly.

Best, Kensal

So how does vertical "muzzle flip" factor into the lateral displacement compensated for by the convergence in a SxS? Seems like it would just be luck if you hit a flying target with all that movement going on.......but like some one said...."it is a shotgun", I guess.