Barrel Convergence Again


Bruce Buck,

I have a new Browning Citori Hunter that I use for trap shooting. I eventually want to shoot doubles. After owning it for 6 months. I thought I should do a little more than patterning and try to determine the exact barrel alignment. The reason I did this was because I was shooting an extra full on the top barrel and whenever I used the Improved modified on the lower barrel I would miss way more and loose track of the correct sight picture.

What I found is that the under barrel shoots 7 inches high and 1 inch right of the upper barrel at 30 yards. Should I just live with this? My engineering brain has trouble with the problem and so have my shooting results. I was planning to add some barrel porting and an adjustable rib to this gun. I have already made a new stock for it.

My original reason to choose the Citori was that it would be very reliable, be made well and be inexpensive.

Should I complain to Browning?

Thanks,

Richard

Dear Richard,

Well, there it is. Welcome to the world of mass production. I’ve covered this before, but it’s about time for a redo. If it makes you feel any better I have seen far larger barrel convergence problems with some Belgian Brownings and Perazzis. I’ve had examples of both that have shot the top barrel a FULL pattern high at 40 yards. That’s 30″ high at 40 yards, not just 7″ at 30 yards. Those guns were disposed of because they didn’t have enough choke in the offending barrel to have it ground on a bias to correct the problem. I also had a Parker Repro that shot the left barrel WAY left. The choke in that barrel was recut to bring the pattern back in. That worked fine because I had enough extra choke thickness in that barrel to be able to give some up when the choke was reconfigured to bring the pattern back in. Still, it isn’t ideal as you are cutting the new choke on an angle and that’s never good for the patterning. Shot traveling 1200 fps doesn’t like to go around corners.

This isn’t a knock on the Superposed or the Perazzi. It’s just a comment to show that even the best guns have problems because NONE of them are regulated by hand. A new Belgian Browning Superposed is in the $8,000 area and a new Perazzi MX8 is almost as much. You’d think that they would properly regulate the guns for that price, but nooooo. The mass-produced screw choke guns like the Citoris and Berettas also have their problems. It just seems to be the luck of the draw. You’d think that they could some up with some super machine that would align the barrels correctly at the factory, but nooooo again.

I think that the manufacturers are counting on the fact that the average shooter doesn’t ever bother to pattern or test his gun for point of impact and barrel convergence. You and I and, of course, all the other astute Shotgun Report readers are the exception. One of the reasons that I always try to buy my guns used is so that I have that inspection period to test the gun for convergence. It’s the first thing that I do. Improper convergence in a gun with fixed chokes can be fixed to some extent as I mention above. With screw chokes you will have to go the route of eccentric screw chokes- a real pain because you always have to get them to index perfectly and you can’t switch chokes from barrel to barrel. They always have to go in the barrel they were made for.

Barrel convergence problems vary from gun to gun. Usually in an O/U it’s the top barrel that shoots high, not the bottom. That’s usually more of a problem because in doubles or flyers, the first shot is at a rising bird and the second shot is often at a flatter bird. Lots of pigeon guns are set up with the first barrel a bit high and the second flat. Still, it’s up to you. If you want them both in the same place, it’s going to drive you loony knowing that one barrel shoots to a different place than the other. It would drive me loony, that’s for sure.

1″ sideways misconvergence at 30 yards isn’t significant. Fugeddaboudid. 7″ vertical at 30 yards can be more of a problem. That translates to close to 9″~10″ at 40 yards. Test the gun at 40 yards and find out what the convergence difference actually is. Do a thorough testing with a variety of shell strengths. Convergence can vary with shooting technique and also with the strength of the shell. Different strength shells can shoot to different points of aim due to recoil and muzzle jump. Once you get your numbers, if they are still bad then call Browning Service and see what they say. The gun makers have barrel convergence standards. You will definitely not be the first person to call with this problem. I think that you are going to be shocked when they tell you what they find perfectly acceptable in barrel alignment. 10″ is about half your effective pattern with a 1 oz load of #7?s at 40 yards. You really don’t want to give that up. I’d love to hear what they tell you.

Best regards,

Bruce Buck
The Technoid writing for Shotgun Report, LLC
(Often in error. Never in doubt.)
http://www.ShotgunReport.com

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2 Responses to Barrel Convergence Again

  1. ron jones says:

    i purchased new 692 top barrel shooting 12 in right bottom shooting 2 ft low at 40 yds sent back to berreta replaced barrels then top barrel near perfect bottom barrel 18 in low they said within their specs i got pissed 600.00 later my gun smith worked over hinge pin lowered .018 remachined after welding in holes and bent barrel now perfect over lapping patterns berretta should not be able to sell guns in usa

  2. jim rennie says:

    Test a bunch of different shot shell loads. My Win. Supreme o/u is manufactured so that the lower barrel actually points higher than the top barrel, and shoots higher with light target loads. However, with some heavy loads of 1 1/4 oz at 1400 fps, the 2 barrels print patterns to the same spot at 30 yards. Obviously, those are the loads I choose to use for waterfowl and pheasants so I don’y have to think about this convergence problem. If you know the 2 barrels shoot differently it messes with your mind and you shoot poorly. If you know the barrels shoot the same, you will shoot better. Experiment……..Jim Rennie.

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