doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Were these barrels shortened?

The theory of filing the muzzle out of square is the escaping gas will push the load opposite the low side. In an old Dixie Gunworks, black powder annual was an article where a gentleman had a collection of St Louis made SxS doubles meant for shooting ball. Several of them had the muzzles out of square in this manner. As I recall at this later date they were made by Hawkins or Meecham.

I would be suspect of a barrel that purposely had the muzzle filed to 'correct' point of aim. I would want to pattern before and after to determine any change good or bad. My quick supposition would be it wouldn't do the pattern any good.

Dean Harris of Skeet's Gun Shop in Tahlequah, OK has a different method of moving patterns to point of aim. He uses a Cratex bob on a long mandrel to reach from the muzzle back to the "transition area", as he calls it, where the bore first begins to constrict into the choke area. He removes metal there, in his own manner, and shoots. This is continued until the pattern has been moved the needed amount, if possible. He has had some phenomenal results.

He has a Sterly 20 of mine right now. One barrel was cross firing badly ............ very badly.

SRH

Phenomenal results in what exactly......moving the pattern, moving the point of aim and/or improving the pattern?

Moving the pattern, or said more accurately, moving the point of impact to the point of aim. His method does not alter the muzzle appearance at all. You cannot look at a gun held in your hands and tell any modification has been done, without the use of a borescope or bore gauge.

When mine comes back I fully expect it to be putting the left barrel pattern dead atop the right's, on the point of aim, and not to either side. Both barrels were good vertically.

SRH

'moving the point of impact to the point of aim'

This I understand and agree with but I remain very curious what happens to the pattern? I'm sure its different for each gun and neither the point of aim or impact have anything to do with the pattern. I also am curious if different shells have different points of impact. I don't remember ever coming across anyone who has done any testing.

Tamid,
If the filing was, as I suspected, to adjust the POI of the pattern, there is no doubt the problem would have been verified by patterning, and patterning would have been performed to gauge the progress of work. Any adjustment would have been for a particular load and different loads might vary.
Mike

I can only answer this based on the limited experience I've had, but that says that you are right. In every case, it opened up the pattern to some extent.

What I used it for was to regulate turkey loads in SxS guns. I wanted one barrel to be very tight, one to be more open, and both of them to shoot to the same spot. In some of those cases there was nothing wrong with the gun; it was just regulated for field loads and I was using extremely heavy loads. That made the right barrel shoot right and the left barrel shoot left.

Filing the open barrel to move it all the way to where the tight barrel was hitting seemed to turn a modified choke into an IC, which was ideal for the loads. I also corrected a cross firing gun that was absolutely worthless for anything prior to the filing. That gun has fixed chokes; all the others I've done have tubes.

It is indeed true that you are regulating it to shoot one particular load if you do this, but all SxS guns are regulated for one general load. The difference may not be enough to matter with most loads, but I'm convinced there is always some difference.

Filing a choke is something best done on a gun with tubes. Ruin it and you are out $20 and can easily replace it. I have only done it on cheap guns that were strictly shooters to me. Stan's gunsmith's method sounds like it would be much better on a better grade gun. Brileys can make eccentric chokes that work on the same principle, but my limited experience with them is that they also degrade the pattern and it still may be off. I found filing and testing often to be the best way for me to regulate a turkey gun.

Thanks Coosa,

What you have written it similar to my thinking.

What options do you have if you have used some method to shift the point of impact and now have a problem pattern? What then can be done to correct the pattern?

Sometimes the very slightest amount of honing/polishing of the choke area itself will dramatically improve a pattern. My first cousin's husband, and my hunting partner, bought a new Browning B2000, 'long about '73 I guess. We shot doves together a lot back then, and he was a pretty good shot. Suddenly, with the new gun, he couldn't shoot nearly as well. After several shoots, and enough time to get used to the gun, it wasn't any better. We patterned it and found that it shot a perfectly donut shaped pattern every shot, regardless the appropriate load. Center of the patterns were almost devoid of any shot. Amazing thing to see. He took it to a local gunsmith who did just a little honing. The patterns were then fine, and he shot that gun very well from then on.

SRH