doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Barrel regulation problem

This may be a silly question. If you have a side by side that seems to have a problem with a set of barrels that were not properly regulated can screw in chokes be installed to correct this problem?

yes....most of the time

I think so. You can also use the "Dremel fix" and do it yourself if the barrels are not too far off. Basically you shave off a tiny amount from the the muzzle in the direction where you want the shot to go.

Sabatti did this to regulate lower-cost double rifles and got badly burned for it - it's tacky to do this on a rifle since the bullet doesn't travel true but on a shotgun it doesn't matter.

I have never done this but have seen results of the technique.

If I were to do it I might try first using a triangular scraper - only a few tho need be removed from the crown.

If the shotgun warrants it, the only other recourse is to have the barrels re-regulated.

Hopefully others will comment on this - perhaps someone who has first-hand knowledge of this technique.

Depending on how much metal/choke you have in that area, you could have a gunsmith eccentrically hone the chokes (similar to installing eccentric choke tubes). Just putting choke tubes into the bbls may not solve your problem, since they should be installed parallel to the existing muzzle line. Briley can advise you on either option. You'll need to be able to tell them how far off of center the offending barrel(s) is/are. Most expensive option would be to strip the ribs and relay them. Spanish gun barrels for the most part are brazed so this isn't possible; only soft soldered barrels can be fixed that way.

Good luck, this problem has been the bane of my existence lately.....test firing for regulation is the only peace of mind when entering into a purchase.
V/r
Maxey

Don't be lulled into thinking it's a price issue either. It can and does happen on low grade guns all the way up to and including Purdeys. I was at a shooting school where a fellow had a brand new Purdey whose right barrel shot 8 inches high and 5 inches to the right. He didn't seem all that concerned although the inctructors were adamant it should be corrected. His wife, who paid for the gun was less than pleased to put it mildly.

For me if you shoot a gun great don't ever shoot it for POI. If it's not right you'll never hit well with it again. Either do it as soon as you get it or stick your head fimrly in the sand and leave it there.

Have the bores been worked on - opened chokes, honing, etc? If not properly done, that could put a straight set of barrels out of regulation.

Heritage Gunsmiths (Jim Eyster) would be another alternative.


+1

Ok for the real answer. I had this gun made from a well known gunmaker here in the U.S.. At the time I was aware of barrel regulation issues they have had. I told them to make sure the gun was regulated.
I never really shot the gun at all till recently. I have yet to put it on the patterning board to really see what it is doing.
This is something I plan on doing in the next few weeks. If I find it is a barrel regulation I suppose I could go back to them since it is gurenteed for life by them.
But I was also thinking of having it tubed. I would like Briley's installed anyway and just wonder if they / and the choke tube installation could correct any barrel issue it may have.
Oh by the way it is a bi-gauge set and I have not shot the other set of barrels.

Hi, I had a problem with B.R. awhile back with a Grulla 209H. At 16yds the right bbl shot 8" to the right and 6" low from the POA. No matter how I mounted the gun, aimed, snap shot it still was that bad.

Briley was able to correct it so it shot about 50/50. All they needed was a pattern sheet when I sent the bbls in to be tubes. They did a wonderful job and the results were what I needed.

Good luck to you, I know how you feel!

Best!

Greg

Just for info. I had Heym make another set of o/u barrels for me. When we test fired it, they were not satisfied with regulation and I was privledged to watch as they corrected it. They used a reamer, with one person turning it from the breech, and another person "crowding" it to the side, with a yoke. The education was worth a lot to me.
Mike

It can be corrected with tubes, but should probably be corrected by either sodering the tubes properly if that is the problem or recutting the choke (which will also open them up) if it is a choke alignment issue.

Barrels out of alignment is more common than some know as most never pattern their guns. Further most alignment issues are minor and not very pronounced.

How well regulated are try-gun barrels? A poorly regulated try-gun could send a lot of shooters off in the wrong direction over the course of 20-30 years . . . .

Until you shoot it on paper from a good rest you will not really know where it shoots.
I just got done patterning a Parker that I opened the chokes on. It didn't shoot where "I thought I was holding", but, I believe it was just my 70 year old shakes.
Bob Jurewicz

Patterning off a bench sounds like a good idea, Bob. Also, I think one should shoot a 5 shot group to really tell where point of impact is....sort of the average of 5 shots...in case of a flinch on one of the pulls which is likely to happen for many shooters. I also recommend Jim Eyster at Heritage Gunsmiths for barrel work. Jim can adjust poi by working on the choke.....eccentric choke, but he can only move the poi about 2 inches or so by that method, as he explained to me.

Does anyone use slugs to determine if a gun is shooting where it should?

Jay

Whole different ballgame, Chas. A gun that throws slugs well (and, few doubles will do that well, unless they were built up as slug guns) may or may not throw patterns to where you are looking.
The slug guns built up by the Bruchet's had a bunch of work done on the barrels to get that to happen. My brother slug hunt with a Savage Fox model B (the cheapie) that consistantly puts the right slug on a pop can sized target at 50 yards-the slug in the left barrel goes, well, some where.

Best,
Ted

Now THAT is funny!

Teddy Bean pontificating on "slugs."

Of course, there IS no higher authority...

Don't worry fellas, I got this.

Allrriiight now, Bob, back to Misfires where you belong. Sure don't need you up here. Heck, Life on the Rez ain't so bad. Besides, it's infinately more interesting then listening to a bunch of old hens cluck about whether they got a magazine or not. I think there's some deep discusion about the Anti-Christ going on, and all kinds of other shenanigans. Let's go see if we can smoke OWD out of that bunker he's hunkered down in. Shoot, if I had Keith and Dave circling above me, even I'd think twice about pokin' my head up.

I wonder if that gun was as ugly as that Boss he was pimpin' a while back?


__________________
Gettin' short and too much time on my hands.
http://youtu.be/i0DysKvt4K0

I'll give you the procedure that was given to me at the school for POI/POA testing that has never failed me.

1) You don't need to shoot off a bench but you do need to be steady, if you can't be steady then shoot off a bench, sticks or whatever you need to. Just don't rest your barrels on anything, especially thin English SxS barrels.

2) You need a rear sight so you can repeat your hold. The proper height is two quarters taped together, I use a bit of poster tack to stick them to the gun so they don't fall off with every shot. Apparently one of the English coins is the thickness of two quarters and that's where it came from.

3) Your sight picture should be resting the bead on top of the quarters. I use a 2" orange stick on dot and hold right on it. Do this at 16 yards. It has two purposes:

A) Adjustments of one inch on the target correlate to 1/16" on the sock which is easy to work with. (Irrelevant if both barrels don't shoot where the're supposed to.) The plus side is if the barrels are properly regulated you'll know what stock corrections to make to get it to fit you.

B) Gross problems will be readily apparent at this distance. The gun may well be regulated for 40 yards but it's extremely difficult to estimate the center of a pattern at that distance. Additionally try to hold on a dot at that distance and you'll see you're pissing in the wind, small movements are going to make big changes. For POI you have to eliminate shake, poor sight alignment and poor hold or this is going to be a waste of time. This is when you'll realize that most shotgun triggers are not so great, throw out patterns where you know you had a bad trigger pull. No gun that is grossly off at this distance is going to be magically on at 30 or 40 yards.

4) One shot per piece of paper, don't shoot overlapping patterns when shooting for POI.

5) If you find your barrels are just a little off then back out to the distance you think the gun is regulated for and test again. That's where you can check your pattern to see if it's acceptable at that distance.

Lastly, I use a computer program (Shotgun Insight) which allows me to take digital pictures of my patterns and analyze them. It will give you a graph showing where you aimed and where the center of the pattern hit. When I sent the printout in to the smith for one of my guns he couldn't believe how useful it was. It really illustrates if something is out of wack and helps prevent a company from saying "we shot it and it's fine." Also it lets me check repair work to see if they're blowing smoke up my a**.

Contact me if you want me to run your patterns through the computer and I'll let you know what set up I need to do it. Essentially all you really need to know is what load you're shooting, the distance, hold point and something in the picture for scale.

That coward belongs here? I think his tag line sums it up pretty well.


Best,
Ted

If you are shooting at a patern plate there two points you may want to consider particulrly with OUs .
1 is the gun being held square on or upright ? It is supprising the number of people that cant a gun into there face so that the barrels are at an angle .
2 is the rib exactly centered and is the bead in the center of the rib? I recently relayed the ribs on a well known make of Italian gun and was supprised to find the rib was originaly one sideded .I have also found it is not uncommon for beads to be off center .OK may be ony a few thou but it all adds up .

I hate to pop your bubble but there are some things even a buzzard won't touch.

Many years ago I had a very long conversation with Jack Rowe a well known gunsmith in this country. Many of you know him. He ssid not to use a rest or a steady mount when patterering a shotguns. His reasoning at that time was this from what I recall

You snap shoot a shotgun, you do not aim it like a rifle. When you are aiming using a bench rest the sight is different that quickly thowing it up and shooting.

Many folks do not mount the gun in the same position each time when they throw it up. I have seen this myself in my shop. If you do not mount the gun cosistently in the same plase when you shoot, how can you determine where the gun shoots.
Maybe Jack is correct. What do you guys think

John Boyd
Quality Arms

John: I think Jack might be correct only because that is the way the Eyster's who have been competition choking shotguns for years do just that. Normally, they have the shooter shoot their gun free hand. And when checking point of impact, they have the shooter shoot a 5-shot group and where the pattern is most dense is that spot of POI. All this is done free-hand. When assessing the pattern itself and rechoking of the gun, single shots are taken with the shell one intends to use in the gun. For example, I had a Browning Superposed 20 bore choked for grouse hunting with Remington Express #7 1/2 shot. As a result of Ken Eyster's (he is now deceased) work, this Browning throws superior patterns with Remington Express at 25 yds for bottom barrel and 30 yds for the top barrel. This is the method they use for all their competition choking of shotguns and they never use a bench rest. Also, they have you shoot your gun on water in assessing poi. I have found Shooting at an object on water useful in assessing where a gun shoots for me. As in all things, there are many ways to skin a cat, but I think the way the Eyster's do it is pretty scientific and effective.

I'm not doubting this Ted, but would like to understand why a barrel would throw a slug away from the center of a shot pattern of the same load weight/velocity fired from the same barrel when held with equally deliberate "aim". The unstated assumption here is that your brother's gun prints that left barrel pattern where it should. Have patterns been fired from this gun with the same steadily aligned hold as with slugs, to remove fit as a significant variable?

I don't discount anecdotes as valid indicators, but they don't explain. I'd like to understand what the Bruchet's did and why.

Jay (After quite a few years I have to ask Ted ... hasn't the Chas. bit gotten kinda stale?)

I was on the phone with Eyster's today and they suggested shooting POI without a rest. They draw a vertical line from the center dot on the pattern sheet down to the bottom. The shooter points the barrels at the bottom of the line and brings the bead up along the line to center, stops when the bead reaches the center dot and pulls the trigger.

An instructor told me of a different free-hand method that he thought corrected the tendency to tilt your head over the comb when "aiming" for POI. If right-handed, face the pattern sheet in a rifleman's stance, and then mount and point the gun at a target high and slightly to the left of the pattern sheet (~70 degrees above horizontal, and 10 o'clock to the pattern sheet). Bring the gun down to the center dot and pull the trigger.

I have heard several stories from gunsmiths about getting different POI patterns on a gun than the pattern sheets sent to them by clients. It sure seems simple in theory . . . .

Surely in this day and age, someone must have invented a gizmo that could use lasers or something to measure barrel concentricity and alignment? Rocketman, are you looking for a new project?

Not Ted, but a slug normally is of lighter weight & with a higher velocity than the standard shot charge for the gauge. Thus bbl times are different & undoubtedly bbl vibrations are also different. If the load "Always" went to exactly where the bbl was pointing at the instant the trigger was pulled all doubles would cross-fire & would never hit point of aim.

Thanks Miller, didn't mean to limit the question to Ted. Understood about shot charge weight and velocity, and I noted these being equal in my question. Since this match is missing for a gun meant to shoot heavier/slower loads you'd have to determine whether their calculated recoil differs and allow some variance for this. Considering the effort the question becomes academic I guess.

I didn't consider barrel vibration, not thinking factors affecting minutes of angle levels of accuracy were in play for shotgun distances.

Jay

You don't use a bench rest when working up loads or zerooing in a double rifle for the same reasons - the gun is designed to be shot from the hands and thereby accommodate muzzle flip. It's a lot easier to see this with a DR where there are only 2 holes in the target after firing both barrels.

The Bruchets sat down at a bench and fired slugs at a range of 55 yards or so. They used a process where the chokes the customer specified were cut while the gun was being regulated. When it was over, they had a gun that put slugs into the black area of the paper (the black area being about a 4" round spot in the center) and whatever chokes Mr. Customer selected, for use with birdshot. Then, the gun went in for proof.

It looked like a pain in the ass. I sold exactly 1 R11 slug gun in my decade plus of importing Darne guns, it was well documented by Mr. Bodio in the article he wrote on the gun for The Double Gun Journal.

Sorry, Jay. I know who "Gunflint Charlie" was to you and thought you might appreciate someone remembering.
Thats all.

Best,
Ted

I think POI of shotguns should be established by shooting off-hand as they are shot at game/targets. Numerous shots per barrel should be shot to get a statistical average.

My apologies Ted. I remember this from a time when we weren't exactly friendly, and I misunderstood. With that in mind, Chas. is fine.

Jay