Just how much is "enough" gun?

[umshiniwam]

I have always preferred being over-gunned rather than under-gunned and have also been critical of people who use
inadequate calibres to shoot larger animals.

I have been wondering lately though, what is "enough gun".

To try and figure this out in a practical sense, I have tackled the question as below.

The 500 Jeffery launching a 570 gr solid will reliably kill any elephant that has walked this earth at 50m.

Under ideal conditions (e.g. broadside heart/lung or side brain shot) one could even argue that a 500 Jeffery is excessive
as a .375 H&H Magnum could do the same if shot placement is correct.

The 500 Jeffery will launch a 570 gr solid with a muzzle velocity of 2,200 fps and the bullet will be travelling at about 2,092 fps at 50m.
At this distance the energy transferred will be 5,541 ft-lb (7,512.59 joules).
A *very* big elephant bull will weigh about 6,800 kg. If you do the maths
it works out to 1.10 joules/kg. (7,512.59 J/6,800 kg)

If you takes this and you multiply it back out to kg for e.g. an eland bull which may weigh a ton, you end up with
1,100 joules (1.10 * 1,000 = 1,100) and hence may deduce that 1,100 joules of energy will reliably kill and eland bull if shot placement is correct
and bullet construction is adequate (i.e. premium bullets are used)

Stop me if I am wrong.

Now go and have a look at the ballistics tables...
A PMP .270 Winchester 150 grain (mv 2,756 fps) bullet at 200 m will be travelling at 2,266 fps and will transfer 2,234 joules of energy.

If my calculations & deduction above are correct, this is twice the amount of energy that will reliably kill a big eland bull.

I realise tha what I am suggesting is that shooting an eland bull at 200m with a .270 is more than equivalent to shooting an elephant at 50m
with a 500 Jeffery. t seems crazy, I know.

Doing the same calculation for the following animals reveals some interesting figures;

Plains zebra stallion (340kg) -> 374 joules
Kudu bull (315kg) -> 346.5 joules
Blue wildebeest bull (260kg) -> 286 joules
Gemsbok bull - (240kg) -> 264 joules
Black wildebeest bull (193kg) -> 212.3 joules
Red hartebeest bull (160kg) -> 176 joules
Warthog boar (114kg) -> 125.4 joules
Blesbok ram (85kg) -> 93.5 joules
Impala ram (75kg) -> 82.5 joules

To give you an idea of how the above relates to bullet energy, consider the following (from PMP ballistic tables, I am too lazy to do the calculations);

223 Rem 55gr with mv of 3215 fps (1711 J), 200 m = 2297 fps (817 J)
243 Win 100gr with mv of 2953 fps (2624 J), 200m = 2424 fps (1698 J)
30-06 Spr 180gr with mv of 2625 fps (3732 J), 200m = 2159 fps (2426 J)

Have I missed something here?

If the above is relative then I/we seriously underestimate how powerful a small or medium bore firearm is. I am not trying to advocate tha twe use smaller
rifle calibres to shoot bigger animals and personally I would not be keen to shoot an Eland bull with a .270 at 200m but it seems that
(with excellent shot placement and a premium bulet) it can be done and the .270 is well up to the task.

Let the debate begin...

[Webster]

I have been saying this for a long, long time! The law does not allow it but you can shoot pretty much anything with a 243 and 100gr premium bullets. Our locally made rhinos are devastating! I dropped a large Hartebeest cow in her tracks last month with an 85gr rhino! A 270 will do the job on almost anything. This might sound ridiculous to those who have shot buffalo but I wonder what a 150gr bullet would do broadside to a buff in the gearbox (someone else can try it and tell me) Will there be enough penetration? I think so - just make sure you have a tree to climb while it dies - you will need a few minutes - maybe less. The 30-06, 7 x 57, 7 x 64 etc will all do the same job. It is not neceassry to use the magnums. We must go back to our roots and learn to hunt again - shooting is not hunting! Get in close, wait for a good angle and then squeeze - it is all about shot placement. Long live the "smaller" calibers happy0065 ;)

[umshiniwam]

Ja well, in the past I would habve said that you were smoking your socks.

Now I am not so sure any more...

What this has demonstarted to me is that I grossly unserestimate just how deadly and powerful a small/medium calibre rifle is.

[kaspaas]

The thing is, it is not that simple.... It is not so much about the energy than about the penetration. Animals are not "knocked out" by the high muzzle energy, but by critical organs being put out of business. In some animals you first need to penetrate quite an amount of tissue to reach these animals. Sure, something like a 30-06 with 220grain solids has ample penetration to kill any elephant if hit correctly, the hole in the critical organ of your choice is just going to be so small, the elephant might only realise he is dead after trampling you...

[umshiniwam]

The thing is, it is not that simple.... It is not so much about the energy than about the penetration. Animals are not "knocked out" by the high muzzle energy, but by critical organs being put out of business. In some animals you first need to penetrate quite an amount of tissue to reach these animals. Sure, something like a 30-06 with 220grain solids has ample penetration to kill any elephant if hit correctly, the hole in the critical organ of your choice is just going to be so small, the elephant might only realise he is dead after trampling you...

Agreed, but penetration is driven by energy. Not so?

You do have a point about the size of the projectile though.

[Arnold]

penetration is driven by momentum ... not energy

assuming two indestructable bullets are used in the same caliber, a light one travelling fast and a heavy one travelling slow but both with the same energy .... if you do the math the heavy slow one has more momentum and thus will stop slower whp

{the momentum is proportional to the bullet weight if the energy is constant}

[umshiniwam]

penetration is driven by momentum ... not energy

assuming two indestructable bullets are used in the same caliber, a light one travelling fast and a heavy one travelling slow but both with the same energy .... if you do the math the heavy slow one has more momentum and thus will stop slower whp

{the momentum is proportional to the bullet weight if the energy is constant}

Makes sense. I thought I was missing something.

[Arnold]

Throw another spanner in the mix … bullets are not indestructible. A bullet’s, with a certain type of construction, weight retention ability is directly affected by impact velocity. The same bullet will lose more weight when impacted at a greater speed.

Taking this into account the light fast bullet will loose more weight and thus penetrate even less …. this is why premium bullets are recommended for fast shooting magnums while sedate bush veld calibres work fine with non premium bullets.

[Kuduvark]

“Enough gun” can really not be answered truthfully unless we also take into consideration bullet construction and bullet performance.

If looking at just the calibre as being “enough gun”, my requirements would be:

1) A calibre able to launch a variety of bullets that will reliably kill the intended target.
2) The calibre must have sufficient power to ensure penetration of the bullet through the frontal skull and the shoulder bones of the target animal.
3) The calibre must be of sufficient power to ensure reliable performance of the bullet, thus ensuring a kill even on marginal shots in the killing zone.

Thus for me, my .30-06 will be enough gun for any animal up to wildebeest.
How ever, even though the .30-06 has and will kill eland reliably, I would consider a .375 as enough gun for such a task.

[Webster]

I will never argue with someone who wants to use more gun BUT the point that was being made was that the smaller calibers are underestimated. The age of bygone hunters did not underestimate them because the age of high speed magnums had not arrived yet. We now have them and suddenly only they are good enough - I say we must talk more to the old hunters who started in the age before magnums and see what they say. I have a good frend whos has shot 49 Kudus with a 100gr softpoint in 243! He will not use anything else - says he does not need it!

This is just something to think about!! My 243 and 270 have accounted for everything up to Blue Wildebeest without a problem. The only BWB I wounded (5 hours of K@K) was with a 375!!