Velocity vs Energy

[J E Custom]

Does the 338 bullet expand at that speed? If not, then i would definately take the expanding 7mm over a non expanding 338...you need to transfer energy to the target for a quicker kill, the non expanding 338 will definitely still kill if you put the bullet in the right place but it may not kill as quickly.

Yes. They are designed to expand within the normal velocity range. (1800 to 2800+) like every other bullet on thin skinned game. only the solids lack the needed expansion.

I hunted elk with a 338 rum using 250 grain bullets and the effective bullet range was over 1100 yards.

I have a 338 RCM in a very light weight rifle, and using the 225 grain bullets at 2950 ft/sec it performs very good on deer and it was built for mountain hunting Elk but doubles as a great hog rifle also.

J E CUSTOM

 

[LaHunter]

Reading posts from guys that kill lots of elk, many of them like the .338 caliber. Many experienced elk hunters will say the .300 mag is better than the 7 mag, but there are lots of elk killed every year with 7 mags.
If you look up the formula for calculating Kinetic Energy, you will see velocity is the biggest contributor to kinetic energy. KE = 1/2mass X Velocity squared. So velocity and energy, while not the same, are very related and energy is very dependent on velocity.
There are lots of other factors to consider beyond energy / velocity for selecting the best cartridge.

 

[26Reload]

I say pick the one you shoot best...either will kill any of the game you listed...
I had a guy from Florida wanted to kill an elk...he brought both rifles with him...he couldn't control either rifle at 100 yards during sitting....i had to finalize both his rifles....ridiculous....
Long story short..all elk were in the ranchers field...rancher killed the biggest bull(as usual)..elk beatcheeks out of field into the mountains...i got this guy down inside a thick nasty brushy road...50 yards from a corner I knew the elk used...several cows came up and thru...then the raghorn stopped at 50 yards broadside....he couldn't shoot...too scared of his rifle....byebye bull.....no way for him to hunt thru the brush after those elk....
Get one..site it...shoot it...be ready......
That's what hunting is about.....

 

[Hand Skills]

As you can see from LaHunter's post, it's a trick question; kinetic energy is (velocity x velocity) x (mass/2). It has a whole lot to do with velocity, only a little bit to do with mass, and nothing to do with anything else.

Im of the opinion the concept of 'energy' should not be debated by mere mortals. Few of us understand what it is in the first place. Those that can wrap their head around the concept recognize that energy must be transferred in order to do work. So regardless of how one looks at it, it always comes back to

Bullet performance

In short;
-pick a bullet designed for your intended target (target density, or weight of animal)
-Use it within it's intended velocity range (velocity window or FPS)
-spin it at an appropriate rate (gyroscopic stability or SG)

If you can do all that and hit your target in the correct area, you'll enjoy great success and never have to think about exterior ballistics again.

There is really no replacement for shot placement.

 

[djm670]

I say pick the one you shoot best...either will kill any of the game you listed...
I had a guy from Florida wanted to kill an elk...he brought both rifles with him...he couldn't control either rifle at 100 yards during sitting....i had to finalize both his rifles....ridiculous....
Long story short..all elk were in the ranchers field...rancher killed the biggest bull(as usual)..elk beatcheeks out of field into the mountains...i got this guy down inside a thick nasty brushy road...50 yards from a corner I knew the elk used...several cows came up and thru...then the raghorn stopped at 50 yards broadside....he couldn't shoot...too scared of his rifle....byebye bull.....no way for him to hunt thru the brush after those elk....
Get one..site it...shoot it...be ready......
That's what hunting is about.....

Ha ha.. and the rancher was shooting a .270 or a .30-06 if not a .25-06. We always used to try and let the paying guests shoot the Elk in the meadow. But it didn't always happen that way if the guest could hit the Elk....

 

[WildRose]

I know this can get a bit dicey but all things considered...
In your opinion, is velocity or energy more important for an ethical kill on big game? I have heard/read various levels of acceptable energy related to game size (1000,1200,1500,2500 ft-lb) but also hear/read that velocity is more important due hydrostatic shock. Personally, I prefer the "wind resistance" of the 7mm for insurance with inaccuracy of wind calls.

Would you choose...

7mm, 180g
2057fps/1692ft-lb
or
338, 250gr
1810fps / 1819 ft-lb

Trying to decide which setup to go with for Elk/Caribou/Moose/Black Bear.

Thanks

Either will certainly get the job done. The .338 gives you a greater margin of error due to the higher energy and larger diameter but the more important factor is your ability to put it where it belongs when you pull the trigger.

 

[FEENIX]

Reading posts from guys that kill lots of elk, many of them like the .338 caliber. Many experienced elk hunters will say the .300 mag is better than the 7 mag, but there are lots of elk killed every year with 7 mags.
If you look up the formula for calculating Kinetic Energy, you will see velocity is the biggest contributor to kinetic energy. KE = 1/2mass X Velocity squared. So velocity and energy, while not the same, are very related and energy is very dependent on velocity.
There are lots of other factors to consider beyond energy / velocity for selecting the best cartridge.

The relationship is directly proportional; any increase in mass or velocity will increase the KE.

KE for 7MM 180G @ 2057 FPS = 35378J

KE for .338 250G @ 1810 FPS = 38045J

Agreed, there are many factors to consider and as Hand Skills noted, shot placement is the "key" and the "nut behind the trigger" must do their part as 26Reload experience shared.

 

[WildRose]

I think On small game the difference won't be as noticable, EXCEPT that the 45/70 does a lot less damage to the meat. In large game, like rhinos, the 45/70 still penetrates thru and thru, while the 30-06 is less than optimal. As a dangerous game stopper, say riled up brown bears or moose or cows even, the heavy for caliber large meplat round will destroy bone without stopping, deflecting, or destroying itself. OTOH, I know an Alaskan who has killed more than fifty brown bears with a 30-06. I say it isn't a good stopper, but it is still a good killer in the hands of a good shooter.

If you show up with a 45/70 to hunt dangerous game in Africa you're probably going to get laughed out of camp.

It simply doesn't have the energy to compete with the African magnums or even the .375 Ruger which gives you 150-200fps more velocity than the .375 H&H.

It's big, it's slow and it's fine for everything we have but not for African dangerous game.

 

[BigGrizz]

Let me simplify this- a 7mm will expand to larger caliber, but a 338 will never get smaller. Period.

The comparison is not apples to apples.

 

[Hand Skills]

The relationship is directly proportional; any increase in mass or velocity will increase the KE.

Directly proportional to mass.

Eg: 180gr @2000fps = 1600ft/lbs

360gr @2000fps = 3200ft/lbs

Double the mass, double the energy.

Exponentially proportional to velocity.

Eg: 180gr @2000fps = 1600ft/lbs

180gr @4000fps = 6400ft/lbs

Double the velocity = 4x the energy.

 

[Hand Skills]

I'm no expert on the subject, but I've read from those experienced in African hunting that MOMENTUM can be a better indicator of performance than ENERGY. I think that's at least 2 separate subjects though

 

[djm670]

I'm no expert on the subject, but I've read from those experienced in African hunting that MOMENTUM can be a better indicator of performance than ENERGY. I think that's at least 2 separate subjects though

Ha ha.. just remember with Momentum... Equal and Opposite, you have to oppose all of that momentum... And as I recall, dangeous game rifles tend to be easy to handle, shorter-lighter....

 

[WildRose]

I'm no expert on the subject, but I've read from those experienced in African hunting that MOMENTUM can be a better indicator of performance than ENERGY. I think that's at least 2 separate subjects though

If I remember right momentum p=mv.

You are right but you don't have the momentum without the mass and velocity.

They also generally will require you to shoot solids as at least your first shot to guarantee max penetration on dangerous game.

 

[WildRose]

Ha ha.. just remember with Momentum... Equal and Opposite, you have to oppose all of that momentum... And as I recall, dangeous game rifles tend to be easy to handle, shorter-lighter....

Definitely not lighter. As a rule the serious DG rifles are double rifles that will weigh in at 9-13lbs to make the recoil more tolerable.