doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Problem: O/U Barrel Regulation

All --

Well, after speaking with both Eyster Heritage Gunsmiths

6441 Bishop Rd.
Centerburg, OH 43011
Ph: (740) 625-6131 ( Corrected address and phone number)


and with Briley Manufacturing -- I now have some understanding as to the degree of correction that can be achieved by these gunsmithing groups in improving the barrel regulation of a double gun -- at least in the limit of screw-in chokes. I was very much impressed with the seeming competency of both groups. Their replies to my questions were very much self-similar.

Both companies modify the the chokes for the respective barrels to achieve the movement of the point of impact for the patterns in the regulation process.

Both companies quoted similar metrics with respect to what can be achieved. The point of impact for a barrel can be moved, perhaps, 6 -- to an absolute maximum of 8 inches -- at the standard 40 yard distance. Tighter chokes can be "moved" greater distances and more reliably at the 6 to 8 inch extremes. Open chokes present more of a problem and this extreme movement may not be achievable. Pattern distortion increases with increasing point of impact movement. This distortion is small and probably unimportant, if the movement is only 2 to 3 inches. Obviously, the screw-in chokes must be used only in the barrel for which they were regulated.

If greater point of impact movement is need, the barrels may be separated and rejoined, properly. In the limit of barrels joined by brazing -- new barrels is the pragmatic solution. If the barrels are joined with "soft", tin-lead, solder, rejoining may be pragmatic. But, the joining with "soft" solders is more subject to fatigue cracking with extensive use.

Jim Eyster did make the point -- that in his experience -- the determination of the point of impact is somewhat sensitive to "who is shooting the gun" and the load being used. For geometric and recoil movement reasons he suggested that SXS barrel regulation was more difficult than O/U regulation for the manufacturers.

It appears that many, if not most, companies, manufacturing double guns, do have problems with barrel regulation -- at least occasionally .... and some more that others. I found some of the barrel regulation "war stories" [b]absolutely appalling in these discussions. I am still incredulous. But, the better manufacturers, that value their reputations, appear to quickly rectify apparent problems.

Browning appears to be the only manufacturer, which at present, is publishing and guaranteeing specifications for barrel regulation. Browning's specification is for a maximum divergence of 3 inches for either barrel from the point of aim. In the worst case -- if the tolerances for the two barrels added -- the divergence in the point of impact between barrels could be as much as 6 inches. As I understand it, typical Browning results are significantly less / better, however. In my view Browning deserves some credit on this basis.

I find this all very interesting. It is absolutely clear that the barrel regulation of double guns cannot be taken for granted -- no matter who the manufacturers is. Please read the last sentence, again.

Buyer beware!

Best Regards,

Don

Don that information cleared up some questions I have had for awhile. Thanks so much for posting it.

Best,

Mike

I'd send it back to Galazan's and have them take care of it. They'll stand behind it. Tell them to make sure it shoots right before they return it. Good luck.

Jimmy --

Based on the technical options available to me with respect to the barrel regulation problems ( or, really, the lack of alternative options ), I sent the 20 Ga. O/U back to Rizzini / Galazan, last Friday. Galazan represents Rizzini in the US and has graciously offered to replace the barrels at their cost, plus a fitting fee. However .... after consider communication with Rizzini in Italy, it appears that Rizzini will only guarantee a point of impact vs. point of aim differential of 4 inches or less at 30 meters for new barrels. That metric corresponds to a 4.8- 4.9 inch differential at 40 yards. The Rizzini metric is thus 60 % higher than that guaranteed by Browning. I find the Rizzini guaranteed barrel regulation metric disappointingly large.

Notwithstanding all of the above, Galazan will attempt to do better.

We will see.

Best Regards,

Don

Just slightly off topic but while we wait for Don's barrels to return, I was thinking about barrel regulation and who builds their barrels to the closest tolerances of point of aim compared to point of inpact; my guess would be the English.
This discussion could get real interesting!!

treblig my current hypothesis is that the two barrel gun shooting to the same point is most important.

I believe that the point of impact of each barrel should be determined by shooting off hand several times out of each barrel at a different target each time.

If the barrels shoot to the same point the stock can be bent to make the POA (point of aim) and the POI (point of impact) coincide.

If the POI of the two barrels are 18" apart as in Don's case if the stock is bent to perfection the best that could be achieved is that one barrel would shoot 9" high and one barrel would shoot 9" low relative to the POA.

And I think with the same gun and charge but different shooters the POI/POA will change from shooter to shooter.

Best,

Mike

All –
I started the thread on this subject in June of 2008 -- and now, this will probably be my last entry on the subject ….. Let it be a warning to all. The problem of barrel regulation in my B. Rizzini, 20 Ga, O/U is coming to an ugly end …. without resolution.

You may recall that I encountered a barrel regulation problem with the B. Rizzini, 20 Ga., O/U, in that, the point of impact for the two barrels diverged by about 16 inches at 40 yards. This is unacceptably poor regulation for a double gun. The maximum divergence for the point of impact for the barrels on a double gun should be no more than 3 to 4 inches at 40 yards.

Regrettably, I detected the problem after the 1 year warranty expired. Thus, my only tenable option was to agree to purchase a new barrel set – but, I insisted that the new barrels meet the 3 to 4 inch divergence criteria. Connecticut Shotgun Manufacturing Co (CSMC / Galazan) represents B. Rizzini in the US, so my communications were with and through CSMC. But, the represented B. Rizzini’s position was that they would only guarantee a divergence of approximately 6 inches at 40 yards. This is a very poor excuse for an acceptable standard.

I sent my gun to CSMC in July of 2008, with the understanding that the barrels would be replaced and fitted – with the gun returned to me in September. That was the CSMC / B. Rizzini stated plan in any event. It never happened.

Well, the saga dragged on interminably. The order was “handed off”, sequentially, to three CSMC representatives. The first was fired or quit. The second misplaced …. and found my gun twice with prompting via resending of the e-mail history. He could not seem to remember the order for the new barrels -- when I contacted him several times by phone or e-mail. I had to bring him up to speed on each subsequent contact. He could not remember what the order was all about.

The third CSMC representative, who took over in September, indicated that that the barrels would be delivered in November. When the November date passed, I contacted him and he indicated that the barrels had not been delivered by B. Rizzini at the expected date. I then had to ask him - press him for a revised plan for the date of delivery. He had no definitive response -- other than to say it should not be more than 60 days. Well, you can all guess that after 60+ days I contacted CSMC. This third CSMC representative indicated that he had no date, yet, for the delivery of the new barrel set from B. Rizzini …. and unbelievably …. he had lost the “thread” and forgotten that the gun was still in the possession of CSMC. So, he suggested that I would have to send the gun to CSMC for barrel fitting. He had never carefully read my multiple notes to him with the complete transaction / communication history over several months. I had to ask that he try to relocate the gun, yet again. It now appears that he has found the gun.

At this point I have asked for the return of the gun ….. with the belief that the situation was truly beyond any reasonable expectation of resolution.

Clearly, CSMC / Galazan demonstrated very “scattered” business practices, having apparently extremely poor business controls and processes. To my great surprise they seemed completely incompetent. I had certainly not anticipated this result, given the image that CSMC wants to portray and their reputed position in the industry . I had not anticipated the B. Rizzini shotgun patterning problem, based on their advertised emphasis on "machining precision".It seems that in this instance that both the gun manufacturer (B. Rizzini) and their US sales representation (CSMC) are sorely lacking in technical and business competency. Absolutely, unbelievable!

When I started my odyssey to own a “good” grouse and woodcock gun a few years ago, I did not expect the project would be all that difficult. But, this odyssey began because my previous shotgun, also, had a barrel regulation problem. At the time I thought that this problem was unusual – perhaps singular. So, I naively purchased the B. Rizzini shotgun. I was in error on multiple counts. Finding a gun that shoots where it points appears to be a non-trivial task. I hope this documentation of my trials and tribulations is helpful to you all and acts as a warning. Buyers beware!

Best Regards,

Don Henderson

Don

I am very sorry to learn about your ongoing difficulty. I have certainly abandoned all ideas of ever buying a Rizzini. As you have suggested, the problem with poor regulation is probably much more wide-spread than realized. The American Rifleman used to publish test patterns as part of their doublegun reviews. They often looked terrible to me.

I have not done any patterning for years, but did do some a long time ago. Results then with Belgian Brownings and a Perazzi showed excellent regulation, both before and after Briley installation. After your problems, I will probably do some this year with my current shotguns. Actually, patterning should be the first thing we all do after acquiring one.

As you note, manufacturers count on us not doing any. This is at least part of the reason that shotguns that look like Perazzis sell for much less. My current 20 ga is a Browning Model 12 pump and will be unless I can afford a Perazzi in the future. Given the economy, that does not appear likely.

I think the comments by Vangulil, above, are probably correct.

Guns are tools; but, in their evolution, the gun designs and their fabrication have been refined to the point of becoming art forms. In fact the art form is now emphasized in many ways over the functionality of the gun as a tool by us, as purchasers.

It appears that guns are rarely critically evaluated by their owners for their function as a tool, such as patterning or the point of impact divergence under discussion in this thread / topic. It takes work and time to do so. This reality appears to not have gone unnoticed by the manufacturers. The manufacturers deliver quality in those features which can be easily / directly evaluated -- essentiallly what can be seen and evaluated in the purchase process. These are basically art form attributes. From the facts, accumulated over time by many contributors in this thread, it appears that the emphasis on the functionality of the gun, as a tool, has regrettably become a "second order" consideration for many manufacturers. We, as buyers of these products, need to turn this around. More emphasis in the gun reviews should be given to functional capabilities and in particular to patterning which characterizes the primary function of the shotgun. As noted in the comments above, many of the, so called, critical shotgun reviews do not report on patterning evaluations. Rather, they report the atributes of the gun which reflect the art form. Many of these, art form, attributes are certainly important. But, if the gun does not shoot where it points -- the art form attributes are reduced to being meaningless in the overall context.

Regards,

Don Henderson

As for the question as to which manufacturers best regulate their barrels, I think the answer would be those who build guns for the most demanding levels of comptetion AND build essentially the same gun for field use. I expect that an Olympic class clays or high stakes flyer shooter with reputation and money riding on performance is not going to accept anything less than outstanding regulation.

Perazzi, Kreighoff, and Fabri come to mind. They are used by top-level competition shooters and their field and target guns differ only in minor details. I am sure there are others.