I'm putting this into the wildcat forum for a reason. Every bench rest, heavy gun, has a custom chamber, if not the cartridge that goes into it. This is the link here; Matt Kline Shoots 2.815″ Record at 1000 Yards with 300 WSM « Daily Bulletin
I admit to being suspicious about the Jamison Patent, but this seems to validate his math. So now the fun begins. Re-designing that heavy gun's chamber into a true wildcat rifle, that is light enough to be of sporting use, in the field, means that we can now use Rick's math as a starting point. These cases do have thick, stout, necks, so I can see why Mr. Kline anneals them for every firing.
My Boer 8 wildcat has just a bit over the case volume of the 300WSM's big brother, the 325 WSM. I have adopted the Speer Hot Core 200 gr. bullet, which is within 5 grs. of this shooter's Berger 210's. I'm happily accepting 600yds. as the max for the old military M-98 Mauser actions, that I use. FWIW, our range does have a steel gong at 500 meters, (550yds.).
Excuses aside, it's been; 'bang-clang', one after another, using only a red dot sight, mounted on the old military rear sight base. And this is with an original BRNO 29" bbl., with a visibly worn muzzle crown. There's no way I'm going to match those 3 inch, 1K yd. groups, even at 550yds., with this setup.
But I do have something that kicks a lot less than my 338RUM, and can also be carried in the field. My point in this thread is that the time in flight, for these, is not a problem, even out to 600 yds. This is getting out into the ranges, of the old black powder buffalo runners'; 'shoot today, kill tomorrow', regimens.
The factory round which I copied, was the old 8x68S Schuler. These are famous for using 220 gr. bullets. The 8mm military Mauser's bbl. twist will certainly stabilize these, but I think a shorter time in flight, for the lighter 185-200 gr. numbers, tip the balance, in the field. I have a box of Sierra 220 Game Kings, and I will still get around to using H1000, to work up some hotter loads than my starter load, which I chrono'd at 2670fps. One thing is for sure, is the new record set here, by the Jamison derived 300WSM, didn't have to factor in action flex, as we do.
So, I'll be working along the lines of a ratio between time in flight, to barrel time/action flexing. I've noted that there are many wildcats proffered on this forum, that are really pretty close to Mr. Jamison's WSM's algorithm.
Alerting the denizens here, to the new world record 1K score, of less than 3.0 inches, seemed to me, to be the thing to do. By building onto this heavy gun's specs, IMO, this should save every wildcatter here, some mathematical headaches. The old 8mm Schuler's reputation was made with 220-225 gr. bullets. These are a might long/heavy for the 300/325WSM, in a short action, with less flex. But I think these world record class 300WSM developments, do steal the thunder away from the really big 338's.
I'll leave it to you folks to determine for yourselves, about how much of Rick's Patent's algorithm, is really, only, it's minimizing action flexing. Mr. Kline's rifle doesn't bother with the 300 WSM's, O.A.L. either. Obviously, he loads it as a single shot, so only those Berger's bearing surfaces matter for his chamber's particular throating.
As for myself, I'm still waiting on Speer to come out with their new deep curl bullets in .323 caliber. These are supposed to minimize the bullet jump in the military 8mm chambers. Mr. Layne Simpson calculated that this bullet jump in the military chambers, cost him a full three inches of barrel, when the same hand loads were shot in both the M-98's and a Rem 700 classic in 8mm Mauser. But I'm sticking with the 32 caliber, over going down to the 7.62mm..