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I do not think it is fair to categorically blame Barnes for their bullets in this sense. If the dimensions of their bullets are compatible with the internal dimension of the barrel shooting them, they'd be safe.

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I can't agree with the above portion of your premise. As I told you, both of the rifles I referred to were slugged. The Barnes bullets used in both actually measured very slightly under groove diameter of the bores in both. OSR occurred quickly in both.

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Did you check neck relief {OD of loaded rounds} and chamber length, OAL and land origin? Is it posible the bullets were pressed into the rifling before firing?

Also, are you certain chambers were concentric and not cocked or seated bullets misaligned in some way that the bullets were presented to the leade in misalignement with it?

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What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?

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Did you check neck relief {OD of loaded rounds} and chamber length, OAL and land origin? Is it posible the bullets were pressed into the rifling before firing?

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Also, are you certain chambers were concentric and not cocked or seated bullets misaligned in some way that the bullets were presented to the leade in misalignement with it?

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"Firstly, Russell (Wilkin of Holland & Holland) points out the fact that double rifles operated without problems for 75 to 100 years. However, late in the twentieth century these problems started to manifest themselves. The only change was the use of a different projectile material"

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I agree with your theory exactly. I've kept my hand close to my chest maybe for too long, in the hope that somebody out there had run a number of experimental tests that could be uncovered and reviewed.

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No over .40 Flanged Nitro Express has a CIP MAP that high (save the .500/.416, which operates at 45,000 PSI with normal loads). So, we know that the bullet can't obturate, for two reasons. The material used is too hard, and there's no compressible core. Barnes says the bullets are slightly undersize, which I don't contest. That helps, but it can't be an answer. A hard .407" mono that has to pass down a .400" bore/.408" groove barrel still has a lot of metal to displace - metal that Barnes specifically states is difficult to displace - in order to conform to the bore. In the thin tubes of a double rifle, that's almost a guarantee of problems.

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No over .40 Flanged Nitro Express has a CIP MAP that high (save the .500/.416, which operates at 45,000 PSI with normal loads). So, we know that the bullet can't obturate, for two reasons. The material used is too hard, and there's no compressible core. Barnes says the bullets are slightly undersize, which I don't contest. That helps, but it can't be an answer. A hard .407" mono that has to pass down a .400" bore/.408" groove barrel still has a lot of metal to displace - metal that Barnes specifically states is difficult to displace - in order to conform to the bore. In the thin tubes of a double rifle, that's almost a guarantee of problems.

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Now THAT makes a lot of sense, best, Mike

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It does and it's pretty basic stuff.

If the driving bands of this bullet described here were the only part of the bullet that met the .407 diameter {.001 under groove depth}, and they were designed correctly, and the rest of the bullet was merely bore riding, there should be no problem at all, even in a thin tube rifle, assuming the charge is worked up to carefully, SOP of course.

I can certainly see how the full groove depth of the bullet, the shank diameter, or the driving band surface area, any of them whether by themselves or in concert together could cause problems. Since {I think} doubles in the older NE calibers vary quite a bit in chamber, leade and bore dimensions, the onus would certainly be on the shooter to make sure modern bullets fit the gun and don't cause any damage. I say modern bullets, and not just Barnes, because it seems we have ever greater numbers of "hard" bullets on the market, some expanding, some "solid". This predicament will probably only get worse as higher and higher performance bullets are demanded by shooters and/or laws require non-lead bullets.

It is interesting, because though in this case it is easy to look back to the "golden years" when just about any bullet was safe for use in a double, it can't be forgotten that many of the old bullets were criticized for poor terminal performance...

Certainly a company like Woodleigh can be commended for sticking to tried and true, but one here has warned against the overuse {?} of their solids, and from what I have seen of them sectioned, I can certainly understand that. Again, personally, I'd check dimensions with a fine tooth comb before shooting any of the hard ones, or really, any bullets at all! I guess being ignorant about doubles might have its advantage, because I have read so much about the wide variations and non-standard chamber/leade/bore dimensions that I'd be checking any bullet at all for every dimension...from cast to jacketed...just like we do with cast bullets.

Is this not always done by old double shooters? Seems like the old guns should be treated like an old wall-hanger front stuffer to me. I mean, just who says Federal .470 {or any other modern maker} is going to fit every .470; old Belgian, Brit, German, whatever, not to mention the reborn moderns. No, I'm not throwing a rock at Federal, but I really wonder. Maybe I'm wrong and the old NE guns are all the same, but I don't think so.

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What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?

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Meaning, a "safe" mono bullet is a bullet that has an undersized shank and bands that allow the displacement of the metal impacted by the lands. BUT.......that bullet must fit the GUN.

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I will agree with that.

I worry that the bullet first shown below has such thick bands that the barrel must bulge to let the bullet pass, and the grooves simply reduce contact area rather than serving as a location to receive the material displaced by the rifling lands.



This bullet appears better able to engrave as the driving bands are thin and the materials is easily displaced into the grooves behind the thin bands.

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This bullet appears better able to engrave as the driving bands are thin and the materials is easily displaced into the grooves behind the thin bands.

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yes dan

But i have seen pictures of the north forks with rather deep engravings in the shank as well,the answer is really not that hard to figure out, less bands and deeper groves to make sure that no harm will come to anybodys gun, but since nobody makes them yet, apparently it is hard to figure out

best

peter

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nigel

i agree and i only shoot the good stuff (woodleighs) as well, but it is true that a time may come when we are only allowed to shoot those pesky mono's, if that time comes i would like to be sure that a bullet is there, that is safe to shoot without damaging the barrels of my guns.

best

peter

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And it will come, sadly im sure of that.

So what about your design is it a secret or are there any info.

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Andreas

"Yeas it kicks like a mule he said, but always remember that its much worse standing on the other end"

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But i have seen pictures of the north forks with rather deep engravings in the shank as well,the answer is really not that hard to figure out, less bands and deeper groves to make sure that no harm will come to anybodys gun, but since nobody makes them yet, apparently it is hard to figure out

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So what about your design is it a secret or are there any info.

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no secret at all:
Sub caliber shank, thin ribs and not that many of them. wide nose with a bit of a curve on them as i find the square nosed ones ugly, this is just a project i have to do for myself, when there might be some time for it.

my biggest job is to gather enough data to determin how small the shank should be, as everybody and their uncle apparently is going for saami or cip spec. which we know wont cut it with the gems we have at home in the cabinet, and also i feel quite strongly that it shouldent cost as much as everybody else is charging for them.

so the two time consumers would be more data collecting and the testing on big nasty critters
last part is the good part though.

best

peter

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Well over at the other place someone is not too happy with "our NE Darryl" and needs a good kick in the ring for his comments he has posted..Serve it up to him Darryl!

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No over .40 Flanged Nitro Express has a CIP MAP that high (save the .500/.416, which operates at 45,000 PSI with normal loads). So, we know that the bullet can't obturate, for two reasons. The material used is too hard, and there's no compressible core. Barnes says the bullets are slightly undersize, which I don't contest. That helps, but it can't be an answer. A hard .407" mono that has to pass down a .400" bore/.408" groove barrel still has a lot of metal to displace - metal that Barnes specifically states is difficult to displace - in order to conform to the bore. In the thin tubes of a double rifle, that's almost a guarantee of problems.

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Now THAT makes a lot of sense, best, Mike

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Yes, it does make a lot of sense. Let's take that full circle.

From Graeme Wright's "Shooting the British Double Rifle":

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Geoff MacDonald who makes the Woodleigh brand of projectiles did an experiment which illustrates the difference in barrel stress with different projectiles. After checking for correct bore and groove diameters, Geoff turned down a section of a .375 barrel until it had .090" wall thickness. He then forced various projectiles through the barrel USING A HYDRAULIC RAM. On the outside of the barrel he had a micrometer set up to measure any expansions of the barrel. When forcing a soft point through, the barrel has no measurable expansion at all. However, a steel solid gave .0005" expansion to the barrel, although the barrel did spring back after the bullet had passed."

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In other words, the jacketed soft point compressed, engraved, and conformed to the bore, with no elastic deformation of the barrel at all. With the steel jacketed solid, compression occurs (due to the soft lead core), but not enough to avoid elastic deformation, and the barrel steel returns to it's pre-stress dimensions. This is not the cause of OSR.

Steel will always return to it's pre-stress dimensions after elastic deformation. That's the DEFINITION of elastic deformation. If it's elastic limit is exceeded, it's original dimensions are permanently altered - which is the definition of PLASTIC deformation. By definition, OSR is plastic deformation. The dimensions of steel can't be altered by stress any other way.

Woodleigh's tests confirm what has long been known - the thin barrel walls common to quality double rifles DO expand SOLELY due to the passage of a bullet too hard to entirely conform to the bore. One of the bullets used in the test was a dead soft LEAD bullet with a thick gilding metal covered steel jacket. The soft core makes it compressible, although less so than a copper or gilding metal jacketed soft point expanding bullet, and elastic, not plastic, deformation occurs. A conventional mono metal bullet (one with no thin full-caliber bands to obviate the problem) has no soft metal core, making it perfectly NON-compressible, and plastic deformation occurs.

On that note let's consider this statement again:

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"The material used to manufacture Barnes Banded Solids will not obturate at less than 45,000 psi."

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Again, no .40+ caliber double rifle cartridge operates at pressures that high. To complete the circle, consider this again:

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So, we know that the bullet can't obturate, for two reasons. The material used is too hard, and there's no compressible core. Barnes says the bullets are slightly undersize, which I don't contest. That helps, but it can't be an answer. A hard .407" mono that has to pass down a .400" bore/.408" groove barrel still has a lot of metal to displace - metal that Barnes specifically states is difficult to displace - in order to conform to the bore. In the thin tubes of a double rifle, that's almost a guarantee of problems.

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The fact that something this basic seems so hard to understand utterly escapes me.

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"Serious rifles have two barrels, everything else just burns gunpowder."

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Well over at the other place someone is not too happy with "our NE Darryl" and needs a good kick in the ring for his comments he has posted..Serve it up to him Darryl!

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The thing is, most discussions, even heated one's on NE still stay civil.

On AR, they end up in a bitch fight of the worst proportions
and normally get way off topic.

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True, and Daryl is doing his best to make this place the same.

Mac said nothing that isn't true.

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In the thread on NE is that one guy is simply a know-it-all ass, and can't be civil, and has no experience where double rifles are concerned. 9.3X57, however is trying to work things out in his mind, but is simply sceptical, but at least willing to discuss the matter, without the other guy's scarcasm. His's take on the subject is a Know-It-All OPINION that is no different from a person who has never ridden in an airplane, telling a pilot how to fly one!

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Not a big thing, but I would differ with him on one point. Making forceful, intentionally insulting comments on a subject that the poster has zero experience with, has done no research on, and that belittle the opinions of professionals who really are expert on the subject, fails to rise to the level of "opinion". It's merely arrogance taken to the level of oral diarrhea.

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