Well, it’s January, and hunting is over until next year.

So, my mind is wandering to Africa, and once again it has pondered the ‘perfect medium bore’.

A brief history:

According to Leslie Simpson back in the last century, a famous African Lion hunter from the US, it was a 358 bore, shooting a 275gr. bullet at 2,500 fps. He said at the time, that this is what the hunting world needed for Lions and thin skinned PG. He told this to Townsend Whelen, who passed the information to his head man at Frankford Arsenal (James Howe of Griffin & Howe fame) where he was in charge. The 35 Whelen was the result, but it fell short of Simpson’s ballistics. Howe moved on to partner with Griffin and they formed Griffin & Howe, where Howe came up with the 350 G&H. It was very close, falling only 50 fps behind the velocity goal. Interestingly, this was in the 1920s, a decade or more after the advent of the 375 H&H, which was even more powerful. But I think it was still a proprietary round, not available to the ‘common man’.

So, today I plugged Simpson’s ballistic request into a ballistic calculator and found this:

WT. (gr.) 275
VEL. (fps) 2,500
CAL. (in.) .358
Calculate
ENERGY 3,815
MOMENTUM 98
TAYLOR KO. 35

So, this is his formula!

I checked out about (5) calibers, some larger and some smaller, to see what would come very close to Simpson’s formula. Of course, there are many more powerful calibers, but I was looking to ‘match’ Simpson’s ballistics, with the smallest rifle weight and smallest head diameter for the round (more cartridges in the magazine). Here is the closest I found, ballistically, in a small, easy to carry rifle: 9.3x62

WT. 286
VEL. 2,450
CAL. .366
Calculate
E. 3,811
M. 100
KO. 36

Conclusion?

In a light 9.3x62, like maybe a Ruger African or my AHR CZ, (7.75 lbs.), one gets:
1) virtually the same energy
2) 2 units more momentum
3) 1 more unit Taylor KO.

So, does this mean I cancel my 358 Norma Mag. project? (I do own a Ruger African in 375 Ruger. WAY more powerful & lightweight, also 7.75 lbs., but carries one less round in the mag.).

Hopefully, this did not take up too much of your winter non-hunting time!!!

Happy winter musings.

Sounds like you need a 375 Weatherby to me

Thanks Chuck375!

But the 375 Weatherby has more rifle weight and more recoil (probably a good idea on the rifle weight for the round).

There are certainly more powerful rifles than the 9.3x62, but I wasn’t looking for more power, but rather a close ‘match’ to Simpson’s suggestion, with 1) the least rifle weight, 2) least recoil, and 3) the highest magazine capacity. But again, still reaching Simpson’s formula.

My Ruger African 375 Ruger holds (3) in the mag.
My Ruger African & AHR CZ 9.3x62 both hold (4) in the mag.
My CZ Custom Shop 9.3x62 holds (5) in the mag. and
My wife’s Sako IV Safari 9.3x62 holds (6) in the mag.

So magazine capacity wise, a big advantage with the .473 head vs. a .532.

Also, I wanted either Simpson’s caliber choice(358) or larger.

The 358NM is really impressive too, but again, has a .532 head size. But if one wanted a 358 caliber, it would be my choice!

I’ve always considered a .375, as a medium- bore....in that line of thought, a .375 H&H,AI, or Weatherby, pushing 250 TTSX or 270 LRX

With the forum criteria for a medium bore...a .338 WM or Weatherby pushing 225 TTSX’s. memtb

My Ruger 77 .338 Win Mag did well on plains game including eland in RSA.
My PH saw it was loaded with230 grain Winchester Black Talon/Fail safe ammo and said it would handle most anything there.

When we were strolling along the Crocodile river and a bull hippo sounded off nearby, he took over my rifle and escorted us out of the area( I had not paid for a Hippo?).

Funny, that is the exact ballistics of my 35 Brown Whelen.

quote:

Originally posted by chuck375:
Sounds like you need a 375 Weatherby to me

Yes . .

I think we both know the answer to this being the 9.3x66 or 370Sako.

286grain bullet at 2550 fps. The energy at the muzzle is 4129. This hits the criterion on the head. A Winchester would hold four down.

Why! can’t FN chamber the Alaskan Model 70 in this cartridge. I would prefer the 9.3x66 barrel stamp. But all Federal Ammo is marked 370 Sako. So, the rifle would need to be so stamped due to custom agent bean counters.

Then there is the 358STA. Problem Nosler does not make a 275 or 300 grain Accubond. That and custom rifle prices.

I just bought a rifle and you start my lust.

No, I am going hunting, I am going hunting, I,am going hunting.

If we are being particle the world could have stopped with the 375 HH. I believe Western had loads for in 1925. Or the 338 WM for something American.

I have 3, 375 Rugers. I do love that case.

Well, the 375 has always been known as the Queen of the Medium bores, and for good reason. It’s the biggest medium bore (by some measures, but a big bore on AR), and also acceptable for DG in almost every African country. So, I get your reasoning fellas.

But if we take AR’s classification of big bore for the 375, then it’s out as the ‘perfect medium bore for Africa’. That would then make the 9.3 or .366 caliber as the largest medium bore, and the ‘new’ Queen. So, looking at Leslie Simpson’s formula, the 9.3x62 fits it to a ‘T’.

Of course, this is just a fun mental exercise for the winter doldrums.

The 358NM is actually better:

WT. 280
VEL. 2,700
CAL. .358
calc.
E. 4,531
M. 108
KO. 38

However, again, less rounds in the mag. (.532), more recoil, heavier rifle.

Many good candidates: 358 STA, 9.3x66, 375 Ruger, H&H, Weatherby, etc.

Considering all criteria, I like the 9.3x66 best. If ammo availability in Africa is of great concern, then it’s still the 9.3x62.

I wanted 358 or larger for cross sectional area, and also to fit Simpson’s formula.

I did run the 338WM however just for a comparison basis. I liked the 338WM with a 275 gr. SAF best for a smaller caliber:

WT. 275
VEL. 2,500
CAL. .338
Calc.
E. 3,815
M. 98
KO. 33

Energy and momentum exactly the same as Simpson’s formula, and KO very close.

Yentna River, very interesting about the Brown Whelen. Could you give me the bullet weight and velocity for that round so I can drop it into the ballistic calculator?

quote:

Originally posted by LHeym500:
I think we both know the answer to this being the 9.3x66 or 370Sako.

Why! can’t FN chamber the Alaskan Model 70 in this cartridge. I would prefer the 9.3x66 barrel stamp. But all Federal Ammo is marked 370 Sako. So, the rifle would need to be so stamped due to custom agent bean counters.

I just bought a rifle and you start my lust.

1) YES! The 9.3x66

2) My 9.3x66 is marked as such (AHR custom). No problem for Africa, because the Federal boxes of 370 Sako are ALSO marked 9.3x66 behind the 370 Sako in parenthesis. Well, the clear boxes are.

3) Sorry about the lust thing...

While not legal for dangerous game, I vote for the 318 Westley Richards.

Just think Surefire, If Elmer Keith would have landed on the 358 instead of 333 or 338. He would have demanded 275 and 310 grain bullet options just as he demanded the 250 and 300 bullet options for the 338 WM.

Personally, I think the 338 WM is perfect with 250 grain bullets at 2700 fps. The exception being the 230 Failsafe. I never got to use that bullet as it was discounted when I was young, but my father in law used it. He still has some and loved it. It is almost a mono metal with a small lead core capped in steel. The steel s surrounded by the copper shank. Unless something goes horribly wrong in a batches manufacture there is no way for the steel to contact the rifling. My father preferred 250 corelockts.

Funny my father in law and father were vastly different in bullet selection, temperament, game hunted but both choose the 338WM. Both had there rifles taken from them due to ill health. My father a couple of heart attacks and his sternum removed. He finished with a 35 Remington. He only owned 2 big game rifles the entire time I knew him the 338 WM and 35 Remington. My father in law a bad car wreck. He still has three,338 WM. But does not shoot them.

My father was healing up from a heart surgery. I was still in elementary school and he got talking about the 338. I went and started reading through my stack of guns mags determined to find a light recoil deer rifle. A few days later I brought him an article on the 25 calibers and suggested the 257 Roberts. I remember being hurt when I could tell that prospect was not a satisfactory replacement.

We got to hunt a handful of times together before hunting for him ended. I remember the last buck he shot at. I was not with him for some reason when he shot at it. We went back together and could not find it. At that time, we determined he missed. Looking back at it, I do not believe he missed. In old age he could hit a blue heron out of the ski with a .22. I think the slow 35 Rem on that day may have not expanded. I think if it happened tomorrow, I could find that buck. Maybe I want this to be true. Though it is best for hunting that he simply missed.

Sorry for the divert. This got me thinking. If you want me to delete, just say so and I will. No issue with that whatsoever.

Now, I need a 338WM.

No problem LHeym500.

Interesting story.

Good luck on your 338WM search!

quote:

Originally posted by cjfoster:
While not legal for dangerous game, I vote for the 318 Westley Richards.

Great round cj!

The ‘original’ 338-06 (in 330 cal.).

As you said, only problem is, not legal for DG.

BUT, the 9.3 (.366) IS legal in most of the commonly hunted coutries in Africa.

Gotta’ stick with my 9.3...

p.s. just traded my wife my FN 338-06 for money I owed her (she’s the brains in that deal). Then, I bought a Dakota Classic Deluxe in the same caliber in ‘like new’ condition for $2,995 on the internet (I was the brains in that deal!). Life’s good.

I know there are a lot of 9.3 cartridges. But one more common 9.3 we have not mentioned is the 9.3X64 Berneeke (sp).

I will always favor the 9.3x66 even though it is a marginal step up from 9.62. The 9.3x64 B is just a little more than the 9.3X66. The 9.3X64B gives you 293 grain bullet at 2500 fps. It is non belted and can fit in a standard/intermediate length Mauser 98 action.

quote:

Originally posted by surefire7:
Well, the 375 has always been known as the Queen of the Medium bores, and for good reason. It’s the biggest medium bore (by some measures, but a big bore on AR), and also acceptable for DG in almost every African country. So, I get your reasoning fellas.

But if we take AR’s classification of big bore for the 375, then it’s out as the ‘perfect medium bore for Africa’. That would then make the 9.3 or .366 caliber as the largest medium bore, and the ‘new’ Queen. So, looking at Leslie Simpson’s formula, the 9.3x62 fits it to a ‘T’.

Of course, this is just a fun mental exercise for the winter doldrums.

The 358NM is actually better:

WT. 280
VEL. 2,700
CAL. .358
calc.
E. 4,531
M. 108
KO. 38

However, again, less rounds in the mag. (.532), more recoil, heavier rifle.

Many good candidates: 358 STA, 9.3x66, 375 Ruger, H&H, Weatherby, etc.

Considering all criteria, I like the 9.3x66 best. If ammo availability in Africa is of great concern, then it’s still the 9.3x62.

I wanted 358 or larger for cross sectional area, and also to fit Simpson’s formula.

I did run the 338WM however just for a comparison basis. I liked the 338WM with a 275 gr. SAF best for a smaller caliber:

WT. 275
VEL. 2,500
CAL. .338
Calc.
E. 3,815
M. 98
KO. 33

Energy and momentum exactly the same as Simpson’s formula, and KO very close.

Yentna River, very interesting about the Brown Whelen. Could you give me the bullet weight and velocity for that round so I can drop it into the ballistic calculator?

375 Weatherby:

WT. 300
VEL 2800
CAL..375
Calc.
E. 5221
M. 120
KO. 45

I've got one in a 7.5 lb rifle including scope. It's a nice caliber.

How about a 9.3x64? Or just continue with the .358 Norma.....

Hey Chuck375, hard to argue with that 375 Weatherby of yours!

And, in a lightweight rifle of 7.5 lbs. Wow. I wonder how the recoil compares to my 7.75 lb. 9.3?

And, how many rounds does it hold? With a .532 case head, is it three or four?

Congrats on a fine sounding lightweight DG capable rifle!

Surefire7,

Absolutely I’ll give it to you,
275gr Woodleigh pp
2500 to 2550 FPS.
24” Douglas barrel 1/12 twist

I have used varget, and H-4350 and settled on varget. Better groups but lost a little velocity. Just over 2500fps with varget. I’ve killed a lot of bears with this load and they go down hard and fast.
I think the 9.3x62 or 9.3x66 in a factory round are just about the same. I’ve never used either one but the numbers are the same.
I’ve used the 375HH and 375WBY as well. I Can’t tell a difference between them and my Brown Whelen on Alaskan game. Same reaction to a good.

quote:

Originally posted by Cougarz:
How about a 9.3x64? Or just continue with the .358 Norma.....

Great question Cougarz.

The 9.3x64 is surely a great round, and more powerful than either my ‘62 or ‘66. But, the case head is larger than .473 (less rounds in the mag.), and ammo is very hard to find in the US. I bought many, many cases of ‘66 ammo when a guy was selling it for about $35/box (can’t remember offhand the exact price, but was $30-something) on the ‘net: SAF, NP, TSX, & BBS. So, I went with the ‘66. And it exceeds Simpson’s formula in all categories.

I still like the 358 Norma too!

How about a 8x68s for general purpose use?

Thanks Yentna River!

Well, heck, you weren’t kidding when you said the Brown Whelen was EXACTLY the Simpson formula: 358 cal., 275 gr. @ 2,500 fps. No need to run that through the calculator...

Congrats on all of your successes on the big bears with your rifle.

Everyone has his opinion, including old guys who wrote some great articles, and some who wrote absolute rubbish!

How do you define large caliber or medium caliber today?

If we are going to go by animals one wants to hunt, for me a 375 of a very big bore.

It kills everything, legally, on this earth.

I have been using one for many years, and have nothing to complain about.

Neither have all the hunters who have been using it either.

Medium?

For everything, close and far away?

One of teh 300 magnums.

I would tend to lean towards the 300 RUM - just because it was a copy of our own 30/404

Well, I guess I get to see if you are right, Saeed.

I had a .300 RUM made on a pre 64 M70 action and its heading to Uganda in a few weeks.

The outfitter wanted me to bring a .416 for Nile buffalo, and since that has worked well for my other buffalo, that's the heavy on this hunt.

If not for the possibility of longer range shooting at Sitatunga, I'd just haul my .30-06 along.

The 300 RUM will certainly makes it easier to hit things at the longer ranges.

Practice and get to judge distance, and remember how much drop your rifle has at those ranges.

On my first PG hunt in SA, I used a Mod 700 Classic reamed to the 35 Whelen Ackley Improved. I loaded the then available Barnes 250X to 2600 and it was a killer indeed! To my mind, it was closer to the 9.3x62 than the standard Whelen. I later used it again with the 200X and it did the same thing as the 250X did! I could live with a 9.3x62, have owned several, but always came back tot he 35 WAI. Old dogs...

quote:

Originally posted by ismith:
How about a 8x68s for general purpose use?

Nothing wrong with an 8x68s for a medium from what I read, and from what some Europeans I have talked to around African campfires. They are big on that caliber. But I do not own one, have never shot one, nor seen any game taken with one. But I have absolutely no doubt, it’d be a great medium bore to own and hunt.

As to the Simpson formula (if you’re interested), here’s how it stacks up, according to the only ballistic data I could find in the 15th ed. of ‘Cartridges of the World’:

8x68s
WT. 220
VEL. 2,700
CAL. .323
Calc.
E. 3,560
M. 84
KO. 27

Again, so you don’t have to go back to the previous post, here is Simpson’s formula: .358, 2,500fps, 275gr:

E. 3,815
M. 98
KO. 35

So, it lags a bit from the formula in all (3) areas. The 338WM comes much closer to Simpson’s ideal:

338WM
E. 3,815
M. 98.
KO. 33

But heck, I would hunt all PG with the 8x68s. I would do the same with a 30-06, and the 8x68s is a step up from it in both caliber and velocity, and therefore a step up in E,M & KO.

Again, I’m not saying the Simpson formula is the answer to all hunting. It was just a winter’s doldrum musing, and one I’ve been interested and curious about for a long time. With today's powders and bullet advancements, many things have changed since Mr. Simson slayed record numbers of Lions with old cup & core bullets.

But, if his formula was the ‘minimum’ or ideal, think of how great that formula would work today with new powders and bullets. I think it’s kinda’ like what Saeed is saying about the 375 bore today. Everything is so much better, ballistically, today than a 100 years ago, that the 375 does today, what the 40+ calibers did a century ago. That is also why I think the 338WM shows so well in Simpson’s formula today, even though it is a smaller bore than the 358.

My goal was to try to find what rounds today ‘match’ the formula. Many fall a little short, and many exceed it. For me at least, it’s been instructive to examine which ones ARE the formula.

So, I do not believe Simpson was looking for the most powerful rifle cartridge in the world. I think he was looking for a MEDIUM bore that he felt comfortable enough with to hunt Lions & PG with a feeling of absolute reliability, ballistically speaking. For him, at that time in history, it was the 358, 2,500fps, 275 gr. bullet. I want the same feeling and ballistics with these additional requirements: 1) least amount of rifle weight, 2) least amount of recoil, 3) holds the most rounds in the magazine, 4) achieves or exceeds the formula.

As to my requirement #4 above, many rounds will achieve or exceed the formula, but at what cost in rifle weight, recoil, or rounds in the magazine?

In my search so far, it’s either the 9.3x62 or ‘66. YMMV.

376,Styer 270 grain bullet at 2600. I believe it fits in an intermediate length action

The 9.3x66 duplicates it.

quote:

Originally posted by LHeym500:
375,Styer 270 grain bullet at 2600. I believe it fits in an intermediate length action

The 9.3x66 duplicates it.

Now there’s a new one to consider. Here it is:

376 Steyr

WT. 270
VEL. 2,600
CAL. .375
calc.
E. 4,052
M. 100
KO. 37

1) it could be made in a light rifle. Case length is only 2.35”.
2) recoil should be tolerable.
3) number of rounds in the mag....?? It’s case head is .501 (9.3x64 shortened) and the rim is rebated.
4) it achieves or exceeds the Simpson formula. (Exceeds)!

This is definitely a contender. It only falls short a bit in my eyes in requirement #3 above. I really don’t know its magazine capacity, but it has to be affected by the head size. The 9.3x62 (and ‘66) are also slightly rebated rim carts, so that shouldn’t be a big problem.

Good idea LHeym500! Now, about that magazine capacity...?

The Steyr Rifles had a four plus one capacity. Steyr rifles were often handicapped, yes
I said handicapped, with 20 inch barrels.

Hornady does seasonal runs of loaded ammo.

When I went to the Selous for Buffalo and plains game I took my Model 70 Winchester in .416 Rem with a 370 grain Northfork bullet for Mbogo. I took another Model 70 Winchester in .358 STA for the plains game. I loaded a 270 grain Northfork soft point bullet at 2850 fps and a 250 grain Northfork bullet at 3000 fps. I shot Zebra, Kongoni, and Impala with the heavy bullet because that is what I had in the rifle when the shots came. My PH said he would not have a problem with me using the STA on Buffalo. I would certainly recommend the .358 STA as an excellent mid range rifle for Africa. My opinion for what it is worth. Good Shooting.

quote:

Originally posted by LHeym500:
The Steyr Rifles had a four plus one capacity. Steyr rifles were often handicapped, yes
I said handicapped, with 20 inch barrels.

Hornady does seasonal runs of loaded ammo.

Good to hear about the 4+1 capacity.

Too bad about the 20” barrel.

quote:

Originally posted by phurley5:
When I went to the Selous for Buffalo and plains game I took my Model 70 Winchester in .416 Rem with a 370 grain Northfork bullet for Mobogo. I took another Model 70 Winchester in .358 STA for the plains game. I loaded a 270 grain Northfork soft point bullet at 2850 fps and a 250 grain Northfork bullet at 3000 fps. I shot Zebra, Kongoni, and Impala with the heavy bullet because that is what I had in the rifle when the shots came. My PH said he would not have a problem with me using the STA on Buffalo. I would certainly recommend the .358 STA as an excellent mid range rifle for Africa. My opinion for what it is worth. Good Shooting.

The 358 STA! Now THAT round takes Simpson’s idea of a powerful 35 caliber to new heights.

I own one myself and love it, a Winchester Custom Shop SS synthetic.

The 358 Norma actually blows past the Simpson formula pretty well, but the STA goes to the next level.

phurley5, what does your rifle weigh? I know the recoil. How many rounds does your hold? And oh, yes it EXCEEDS Simpson’s formula!!

I actually have two STA’s, each a Custom. The one I took to Africa is from the Winchester Custom shop that I put a Weatherby Accubrake muzzle brake on and it shoots quite well. I can put three down below for follow up shots. That rifle has the most beautiful wood you would expect from the Custom shop. My other STA is a Custom with a pre-64 Model 70 Winchester with a Vies Brake. Both are extremely accurate when the shooter does his part. It would have the same capacity for back up shots. I know the STA exceed your speed guide lines but I like speed in everything I shoot. Good Shooting.

quote:

Originally posted by LHeym500:
376,Styer 270 grain bullet at 2600. I believe it fits in an intermediate length action

The 9.3x66 duplicates it.

I built a .376 Steyr on a VZ-24 23" bbl easy conversion on a M-98

Short barrels are so rediculous on European rifles meant for high velocity.

Magazine capacity has never been any bother to me.

I have been hunting with a rifle that takes 2 in the magazine and one in the chamber.

And it is a dangerous game rifle too.

Several hundreds of assorted elephants, buffalo, lion, leopard, hippos etc have been shot by it.

Never felt magazine capacity was a hindrance.

quote:

Originally posted by Saeed:
Short barrels are so rediculous on European rifles meant for high velocity.

Magazine capacity has never been any bother to me.

I have been hunting with a rifle that takes 2 in the magazine and one in the chamber.

And it is a dangerous game rifle too.

Several hundreds of assorted elephants, buffalo, lion, leopard, hippos etc have been shot by it.

Never felt magazine capacity was a hindrance.

Heh. If I recall corectly, John Hunter's magazine was usually the second barrel of his double. For lions, elephants, rhinos, buffalos and even leopards. And the technique he preferred was to have the animals charge him.

So, just for the fun of it, if two rounds is enough for the many double rifle owners, why not go all the way and shoot a single shot? Much lighter rifle.

If one says, ‘well, two is just for insurance’, then wouldn’t three be better like Saeed’s rifle?

And if three rounds is better, then....

Anyone feel they have a corner on the truth out there?

I will repeat my earlier words...to each their own I say!

A 30-06, 300 WM, 338WM... doesn’t matter. I’d be more interested in the rifle itself. Luckily for me I don’t need the perfect caliber, not anymore.

This thread had been a lot of fun for me!

Thanks to everyone who has played along.

Chasing the ‘perfect medium bore’ (or any bore) is like chasing the Holy Grail. The journey is the reward.

To the average hunter, the rifle is just a tool. To most AR members, I suspect it is a bit more. I belong to the latter group.

Whichever rifle/round you have chosen to hunt with, it is the perfect choice.

And fear not. Winter can’t last forever...

If you have more to contribute, let’s hear it!