Same energy from lighter bullets really the same?

[wictor]

Hopefully I can explain this in some sort of sense

They have minimum calibre laws for hunting. Here in VIC 130gr .270 diameter bullet or larger for Sambar. I've put some numbers into the JBM ballistics calculator and get this which is where I start to wonder.

Picking the lightest .270 load with a 130gr bullet from the ADI website I get this.

Muzzle velocity 2,720.
Energy at 100m 1,730 ft-lbs.
Energy at 200m 1,330 ft-lbs.

If I put in the details for a max .243 load with a 105gr pill I get this.

Muzzle velocity 3,000
Energy at 100m 1,830 ft-lbs.
Energy at 200m 1,600 ft-lbs.

(I've rounded a few numbers to make it neater but that's about right, only 5-6 here or there.)

The Gov says the top load is fine, but the bottom load is illegal for hunting Sambar.

On paper though it looks better? I could have a .243 and do everything going by that.

So why couldn't I use a .243 after looking at those numbers?

Does that not come across in practice? Does a lighter bullet not do the right job even if it hits with more energy?

Help a noob understand

[Chronos]

Possibly simply because of the way your state laws are written, if it says min caliber .270, min bullet weight 130gr you'd need to meet both those criteria

If it said something else you could try and interpret it a different way.

Truth is the caliber restrictions are there for a reason. To stop people hunting sambar with a .223. Why? Because not every hunter who thinks they can head shoot a deer at 60y can actually do it, a highly fragile 65gr .243 varmint bullet may not reach the vital zones and because it's not in the interest of the hunting community to have wounded animals wandering off only to die of infection days or weeks later.

I'm sure there are hundreds of hunters in Victoria capable of taking even a large deer with a .243 or 6.5x55 but the limit had to be set somewhere and 130gr .270 is it.

Like our road rules they're written to protect us from the 5% of idiots who'd put us all at risk

Chronos

[Swarm]

Using energy as the benchmark would make sense, but I reckon it would be too difficult to enforce to be practical.

If you found someone in a deer reserve with a Sambar in his truck and he's got a .223 on him and not a .270 you can easily show he's in the wrong.
(of course none of us do this, just for the sake of argument )

If he's got a .243 how are they going to establish whether his load is up to scratch? They're not going to pull pills and weigh them and confiscate cartridges to do ballistics tests for energy tables are they.

[BBJ]

Does that not come across in practice? Does a lighter bullet not do the right job even if it hits with more energy?

Energy figured in a calculator aren't necessarily going to translate to transferable energy in a real word situation.

A heavier, slower bullet is going to have much better weight retention and create a desirable wound channel for a clean kill.

A lighter, high velocity bullet may well hit with more potential energy at the time of impact, but it's just as likely to turn to shrapnel and shred a large area of non-vital tissue - leading to the undesirable situation Chronos described.

There is a reason weight retention is the focus of so many hunting conversations.

[AusC]

To stop people hunting sambar with a .223. Why? Because not every hunter who thinks they can head shoot a deer at 60y can actually do it

It always ruffles a few feathers when it's said but no-one can do a perfect head-shot every time.

To be blunt about it, anyone who won't concede otherwise is a fool or a liar.

[wictor]

Because not every hunter who thinks they can head shoot a deer at 60y can actually do it

A lighter, high velocity bullet may well hit with more potential energy at the time of impact, but it's just as likely to turn to shrapnel and shred a large area of non-vital tissue - leading to the undesirable situation Chronos described.

That all makes sense.

[Norton]

It always ruffles a few feathers when it's said but no-one can do a perfect head-shot every time.

To be blunt about it, anyone who won't concede otherwise is a fool or a liar.

But, but... My precious ego!

[Press]

Pfffft,

Norton, with your .416 you're probably just hitting them in the shoulder and there isn't enough left to tell where you hit it.

Doesn't count as a headshot when you've destroyed everything and the head just got caught in the mix

[Norton]

I'm going to stick with the theory that I'm just awesome if it's all the same