doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Gun reboring and regulating.

Apparently, Holland & Holland disagrees with gunman re shotguns shooting to point of aim. From Vic Venters' book "Gun Craft", chapter entitled "Hand-Regulating Chokes"--which is based on a visit Venters made to H&H, and an interview with barrel guru Steve Cranston:

"Cranston's ultimate goals are to ensure that the gun prints its patterns to point of aim . . ."

Further on, same chapter: "At the most fundamental, Holland's entire barrelmaking process--including Cranston's careful choke regulation--does assure that the chamber, forcing cone, bore, choke cone and parallel are all concentric with one another and that both barrels will print where pointed when fed appropriate loads."

If the right barrel typically throws its pattern high and left of center at 25 yards and the left the opposite, then the patterns from the two barrels would be farther off in their respective directions at 40 yards . . . and it'd be a bloody miracle if you hit anything, especially with a tight choke (which you start to need at that range). That is, unless the distance from point of aim is only very slight, so that the patterns mostly overlap, even if not perfectly.

And if shooting to point of aim isn't what we should expect to get, then those who use try guns and pattern plates to do a fitting must be wasting their time.

Obviously, shotguns aren't rifles, and the spread of a pattern will compensate for relatively small divergences from point of aim. But they'd better be really small at close range--one standard distance to evaluate barrels shooting to point of aim being 16 yards--or they're going to become pretty significant at longer range.

Gents you can believe what you like ,that the world is flat or that that using a certain after shave makes you irritable to women . Must be true I have seen it in a magazine and on the internet .

Mr Brown a single shotgun barrel will shoot where it is pointed it is impossible for it not to do so . But a pair of shotgun barrels is a different matter .
Sorry but there is no point in my continuing this thread as I can see I am not able to persuade you to my point of view , not being childish just don't like banging my head against a wall.

Pretty much a contradiction to what you said in the earlier post.



OBTW, didn't you mean irresistable, instead of irritable?

SRH

Gentlemen, I see what Gunman is trying to describe and tend to agree with him. I cannot speak for guns such as Holland's but believe his statement to be true for the vast majority of guns. For instance, a 2 frame Parker has a set distance between the firing pins and whether the barrels were made 26", 28" or 32" they touch at the muzzle. And I seriously doubt there was any tweaking of the chokes to change point of impact. In a factory setting producing large numbers of guns there simply wouldn't have been time for such niceties. And no one is going to convince me that makers in the Gun Quarter in Birmingham took their guns to a shooting area outside of town and went through the profitless process of regulating POI on each gun. It just makes sense the tubes were carefully joined on the same plane and that was that. Just MHO so pardon my ignorance.

Well . . . they're not rifles, and the fact that you're throwing a pattern with a fairly wide spread makes up for some SLIGHT differences in shooting to point of aim. But think of it this way: If the right barrel were off significantly one way and the left barrel were off significantly in the other direction, then the shooters would have to think: "OK, now I'm shooting my right barrel, which means I have to compensate in this direction; woops, now it's the left barrel, so I have to compensate in the opposite direction. Chaos. But even double rifles are made so that the barrels shoot to the same point of aim at a given distance--and while a double rifle isn't a real long range weapon, we're talking longer ranges than even long shots with a shotgun. If it can be done satisfactorily with a double rifle, why not with a double shotgun?

Last year I sent a vintage American gun of excellent quality to a good barrel man to have the chokes opened up. But out of curiosity I also asked him to pattern it before, during and after "regulating". He called one day and began by saying "these barrels must have been joined on a Monday by someone who had a bad weekend". He went on with describing how one barrel shot to POI but the right shot about six inches out at 16 yards! He did ask if I wanted it fixed cause as is the gun gave me plenty of excuses for my frequent misses. Feeling I had enough other ways to explain away my misses I told him to go ahead. Well, with a lot of reaming, polishing and patterning he brought them to the same POI. fortunately the muzzles had a lot of metal to work with. Point of this post is that even one of the premier makers did not take time to fine tune where they shot.

Incidentally, shop rates at the pattern board were enough to buy many flats of ammunition.

I intentionally left off the maker so this thread wouldn't turn into a spitting match. But they were good.

Maybe that example goes to the point of the original thought. Even if the manufacturer didn't do it, it's possible for a smith to change the point of impact or have a different goal of regulating a gun than changing bore or choke dimensions. The thing I was thinking though is that I've noticed point of impact can change some between shooters. Maybe based on how the gun recoils for their hold, particularly the lower the velocity.

First & Foremost "NO" reputable gunmaker built that reputation by putting out guns of which the Surer your hold the more certain you were to "Miss". To say those barrels were not "Tweaked" after their original assembly is one thing. To say they were totally Sans Regulation is another thing altogether. They were by design assembled in such a predetermined way as to within reason assure they would Hit with reasonable accuracy for a shotgun to the same point of aim. That in & of itself is regulation. From what knowledge I have seen in the past "Long Before the Internet" many gunmakers did maintain an in House shooting range & did fire their guns for both pattern & placement. No doubt only in severe cases was any further action needed, & even then no doubt a few slipped through the cracks, as witnessed by Joe's gun.
To imply as gunman did that the only consideration was that the muzzles touch with total disregard as to whether they shot to point of aim, I simply Cannot & Do Not accept. As I said in an earlier post on this same thread Not All SxS doubles left the factory with the muzzles touching. It is not uncommon to find a short barreled gun built on a wide frame with a factory installed keel between the barrels at the muzzle. Why, well simple, to have placed them together would have created a cross firing gun.

And old friend of mine, a gunsmith, had a pretty serious trap shooter for a neighbor. Chuck told me about tinkering with the choke on the trap gun, making it slightly eccentric, in order to move the pattern. (Might well have been a double, probably an OU, but can't recall for sure.) Time consuming, but per the above, it can be done. But while I don't claim to have looked at nearly as many patterns as someone like Bob Brister, the ones I have shot pretty much tell me that most sxs--even relatively inexpensive ones--aren't off a great deal when it comes to shooting to point of aim. I can only recall one example that was really bad. Close to as bad as the one in Joe's post.

I haven't found that to be the case, Larry. I have seen many S x S and O/U that weren't regulated. In fact, so many that, when I buy a gun, I "hold my breath" until I pattern it and see if it is regulated or not. I have found many that were not. Maybe I'm just "lucky".

Beretta told us years ago that they will not provide corrective action on a double they built unless it is off by more than 8", I think at 25 yds. Eight inches is horrible, IMO. I will not own a gun that is off by that much.

SRH