David,
There is nothing wrong with putting the 9.3x64 in a Mauser action, the cartridge was designed for it. The 9.3x62 is in between the .35 Whelen and the .375 Whelen as far as power is concerned, whereas the 9.3x64 is significantly more powerful.
It does take some work to get the x64 into the Mauser but nothing that a trained gunsmith can't handle. Feeding is paramount if you plan on taking it to Africa. This has to be absolutely 'NO FAIL' over there. Failure to feed can mean injury at the least and death at the worst.
I consider either cartridge to be superb but I think that the 9.3x64 deserves first shot in Africa. I shoot both and they are both in Mausers. Brass is also available through Natchez, although they may be out on occasion. Be sure to look around for bullets. The selection has improved quite a bit.
Here is some additional information:
9.3x62 Mauser
Some time ago someone said, �Necessity is the mother of invention.� In a way this fits the birth of the 9.3x62. The necessity came from the European farmers and ranchers in Africa who had a need for a firearm that was affordable and yet had enough punch to handle the tenacious crop raiders and large predators they were plagued with. Most cartridges of that time were adequate to handle most plains game, but when it came to dangerous critters, they needed something bigger.
Big-bore double guns were the answer but were financially out of reach for all but the well-heeled. They needed one rifle that would do it all and still fit their pocketbook.
In 1905 German gunmaker, cartridge designer Otto Bock came up with the answer. Using the strong military 98 Mauser action, he designed a cartridge that would fit and feed through the standard-length action. Using a case near identical to the .30-06, he developed the 9.3x62, which with softnosed bullets was more than adequate for even the largest of the antelope, and with solids it had enough sectional density to penetrate and do in the big boys.
An interesting note taken from the recent A-Square loading manual shows just how much respect the 9.3x62 has. It seems that in 1958 when Kenya ruled, the .375 H&H was the minimum cartridge allowed for dangerous game. A footnote was added that the 9.3x62 could be used by experienced hunters.
The 9.3x62's combination of moderate velocity with bullets of high sectional density and a large frontal area (diameter) has proven itself so well it is still one of the most popular cartridges outside the U.S. for any big game. So popular, it is offered by most all European rifle manufacturers today.
When looking at the 9.3x62 by itself, it looks like a .35 Whelen or .338-06. However, when placed side by side, it is obvious which of the three is larger and has a slight edge in case capacity. Even though the 9.3x62 is a slight bit shorter in length (1mm), its straighter case walls and shorter neck give it the advantage.
It is understandable why, in the U.S., the 9.3x62 was not popular in the past. Bullet selection was minimal and availability was spotty. Not so today, as most major U.S. manufacturers produce a selection of 9.3mm bullets along with the normal imported offerings of Norma, Woodleigh and Brenneke. Weights from 234 to 300 grains are available. The most popular bullet weight has always been the 286 grainer.
Factory ammunition and brass are readily available from Norma or RWS; however, it is not a big problem to use .30-06 brass. The normal fireforming process is all that is needed.
Loading data can be found in most all the popular manuals. Nosler, Swift, Barnes, Speer, Norma and A-Square all list extensive data for the 9.3x62.
The 9.3x62 seems to be one of those cartridges that is not finicky to load for. Most all loads tested shot well, some just better than others. This is a hunting cartridge using hunting bullets, but in some cases accuracy was well inside one inch at 100 yards.
9.3x64 Brenneke
If there was ever an overlooked cartridge that was adequate for any big game anywhere in the world, including the dangerous game of Africa, it could well be the 9.3x64 Brenneke. It was the brainchild of Wilhelm Brenneke in the period around 1910 and was the largest and most powerful of the Brenneke cartridges. The cartridge had an enthusiastic acceptance from big game hunters in Europe, and it didn�t take long for it to find its way to Africa.
The infamous ivory hunter John Taylor rated the 9.3x64 Brenneke as an excellent medium-bore cartridge right along side the .375 H&H Magnum. Not only was Taylor a professional ivory hunter, but he was also a student of ballistics and cartridge performance. Taylor�s theories of knock-out power expounded upon in his books are still considered by some as a valid comparison of different cartridges.
Two things contributed to why the 9.3x64 Brenneke never gained the interest of American hunters. First was the lack of adequate bullets that could perform under the higher velocities, and second was the advent of World War II, which stopped all production of German sporting firearms for quite a few years. In the meantime the .375 H&H proved its worth and is still doing so today.
When European arms manufacturers started production of sporting firearms, sometime after World War II, the 9.3x64 Brenneke surfaced again, slowly gaining popularity as ammunition and components became available. Within the last few years, premium 9.3 bullets such as the Barnes X-Bullet, Swift A-Frame, Nosler Partition and others have made the 9.3x64 Brenneke a cartridge to take note of.
Ballistically it is the near twin to the .375 H&H. Factory loadings for the .375 H&H 300-grain bullet list a velocity of 2,530 fps. The 9.3x64 Brenneke factory load for the 286-grain bullet is 2,690 fps. With a bore size difference of only .009 inch (.375 versus .366) and a bullet weight difference of only 14 grains, you can see how close in performance they are. When you do the math, it even gives the edge to the 9.3x64 Brenneke.
When handloaded the 9.3x64 Brenneke is very impressive. Easy to load with its nonbelted case, the Brenneke, like the 9.3x62, shoots most any load well. Bullets in the 250- to 270-grain range work superbly on any big game in North America. The heavier 286-grain bullets in either softpoint or solid work well on the big boys.
With the 9.3x64 Brenneke there is one big plus and one small inconvenience. The plus is that any standard-length action can be used. If a .30-06 or action of that length and bolt face configuration is used, the only alteration needed is to open the bolt face to accept the .496-inch rim of the 9.3x64 Brenneke brass, screw in the barrel and head for the range.
The inconvenience is obtaining brass. The only manufacturer of loaded ammunition and brass is RWS. It is imported in sufficient quantities, but you won�t find it at Wal-Mart. Most any specialty gun/reloading store will be able to get it for you. A one-shot purchase of 100 rounds of brass should last a near lifetime, as case life is very good.
After using the three 9.3 cartridges over the past few years, I can�t help but be impressed. When ranges are kept within a reasonable distance, the performance, with proper bullets, gets the job done as well as any cartridge on the market. Friends and hunting companions who have witnessed or used any of the 9.3s on big game have come away with praise, and some have gone on to build their own 9.3s.
It is interesting to note that with all the new ultras, shorts, belted magnums, etc. that have surfaced over the past 30 to 40 years, none do any better job as all-purpose cartridges than the ones designed by Otto and Wilhelm 100 years ago.
http://www.riflemagazine.com/magazine/article.cfm?magid=95&tocid=1379