Pretty ignorant post. You obviously are completely ignorant of the cause of OSR, as well as of the test conducted, but you sure like to spout off as if you're not.

I've been exclusively a double rifle shooter for over 20 years, have had damage to DRs from monos, and have been discussing this issue with gunmakers, other serious double rifle shooters, and recognized experts in the DR field the entire time. Contrary to what 9.3 thinks, there are a lot of very well informed professional people with first hand experience with this problem. I've never found a single one of them that believes that excessive operating pressure has anything to do with the OSR, loose ribs and, sometimes, bent barrels characteristic of this damage.

OSR is the result of the expansion of the necessarily thin walls of double rifle barrels, caused by the passage of a bullet too hard to obturate, to the extent of exceeding recoverable deformation - the steel doesn't return to it's original shape. Also, the passage of this bulge down the barrel can flex the solder joints, causing them to fail. There are documented cases of barrels that actually bent.

Chamber pressure is no part of the puzzle, excessive or otherwise. One bullet maker (Woodleigh, I think) tested this by driving bullets down a barrel by hand, and measuring the expansion over the bullet as it was driven down the barrel. Soft, lead core bullets made a very small bulge, or none at all, as they passed down through the thinner sections up forward because the lead core is compressible, permitting the bullet to obturate. Bullets that are too hard to obturate made a large bulge. Mono-metals don't have a lead core that permits them to compress, so they can't obturate.

I spent some time on the phone with Ty about what Barnes had done to determine the suitability of their bullets for double rifles. I was careful to make sure that I understood what he said. Look at the link. The "take" was over the chamber ONLY. The expansion over the chamber gives you chamber pressure only, that's how a strain gauge works. No attempt was made to measure expansion downtube caused by the passage of the bullet itself - and there is no controversy that it is that expansion that causes the damage. I had this conversation with them maybe a couple years ago, many years after my complaint to them about damage to a double rifle from Barnes X, plus another from their mono solids.

...and not so easy to take them. If you had basic knowledge of quality double guns, you'd know why.

If you had a good quality gun with well-struck barrels next to a cheap machine made gun with very poorly finished barrels, would the difference be obvious? Of course, a blind baby could see it. Could you photograph it and capture the difference? Good luck. You look for OSR in exactly the same way that you examine a Purdey best for perfectly struck barrels.

Tell you what. I have ready access to five double rifles with OSR. I'm sure you're right and I'm wrong. I'm sure it's simple to capture on film. I haven't figured out how yet, and I'm sure you'll know exactly what to do. Come show us how it's done.

Well, let's see. You don't own, and never have owned, a double rifle. If you have I think you would have mentioned it. As such you haven't had the experience, or the worry, that we long-time DR shooters have had. We've had the need to research this issue and make our own choices, and some of us have actually observed direct cause and effect first hand. So, you don't have any experience with the subject matter, or knowledge of it, nor do you have any reason to. You're also the only one trying to make this discussion exclusive to one brand, which it is not. And, you seem to have a need to make a statement about a long-settled issue. You obviously have an agenda, but your manner proves that it isn't to help anyone, or to gain knowledge, let alone the truth.

Yeah. Right.

The direction this discussion has taken is a waste of time, as OSR and it's cause is a long since settled matter. Once again, for anyone with a genuine desire to better understand OSR, no one has liaised with the trade on this issue as much as Graeme Wright has. The third edition of his book, "Shooting the British Double Rifle" has just been released, and his discussion of the issue is the best I've seen. The list of names of the principals of the double rifle making trade that he has consulted in researching this work is exhaustive.

Here are a few excerpted comments from it that I posted on another string: