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In 1971 I ordered a Krieghoff Teck O/U DR in caliber .458 Winchester Magnum, with interchangeable barrels in .375 H&H. At the time, Kynoch had ceased production of NE calibers and there appeared to be no prospect of any in the future. I was concerned with ammunition availability in Africa and I wanted a supply of fresh ammunition, not loaded with cordite. For the same reason, my bolt gun choice was a Model 70 Winchester (pre-64, of course) in .300 H&H.

When I received the Krieghoff, the .458 barrels functioned flawlessly. The .375's were another story. The cases would stick so tight that they had to be driven out with a cleaning rod. I took the rifle by Krieghoff on the way to Africa and had them correct the problem (I still don't know how) and furnish me with spare extractors fitted to the individual barrel sets. I have never had cause to use them, and the barrel sets worked flawlessly in Africa. Incidentally, with all the stress on the extractors, trying to remove the stuck cases, they never pulled through the brass or otherwise malfunctioned.

I believe that the problem with cases like the .375, with its sloping shoulders and tapered body, is that the DR action springs open slightly at the moment of ignition, then springs back, wedging the now expanded tapered case back into the chamber. A straight sided case like the .458 does not produce the same wedging action (nor would a .300 Winchester Magnum). It is counter intuitive, but I firmly believe that the straighter the case, the better adapted it is to a DR or SS.

Soon afterwards, I designed a cartridge based on the .375 Flanged case, opened up to .458, a sort of flanged .458 Lott. I loaded it to .450 NE velocity and had a rifle made up by Krieghoff to fire it. It worked like a charm and I thought it should have been a commercial success, considering the fact that the .458 has much too little case capacity for use in a DR or SS. Unfortuantely, in a weak moment I sold the rifle, but another is presently in the works. One drawback with the original rifle was that the available cases were Berdan primed and poor quality, meaning that one in three would split in the fire forming process. Modern, Boxer primed cases, are far superior.

I presently have three DR's in the works, all Krieghoffs. One is a SL Ulm model, in 9.3X74R, the second a Teck BL in .500 NE, with interchangeable barrels in 8X75RS, and the third is the aforesaid .450 on the .375 Flanged case, called .450 C&W by me.

The issue for me is not so much the rimmed-rimless question, but using a cartridge which was not designed to be used in a bolt action, with bolt action pressures. None of the cartridges named above develops the pressures used by their bolt gun counterparts, even in factory loads, for the simple reason that their lengths are not determined by the length of a bolt action receiver. With the intensity missing, extraction ceases to be an issue, barring pitted chambers or some other anomoly.