300 BO, 308 Win, 30-06, 300 WM, 300 RUM.....speed kills!

[Nathan]

I could have chose any caliber and shown this perspective. As bigger case gets put behind the bullet, more power and energy is the result. As I increase case size, negatives arise like longer heavier actions, less mag capacity, more recoil, etc....

So why when max loads or a small cartridge size increase are discussed is this the common sentiment,

....about 100 FPS faster than the same bullet out of a <next smaller round> . A target, animal, etc won't know the difference though.

??

My point is the larger cartridges weren’t designed because there’s no impact to the trajectory or to the ability to provide terminal performance on game, these comments show a lack of understanding of the value of increased velocity. A 308 is not a 300 WinMag. Maybe the different ranges that they go subsonic can be our guide as to how science shows is that?

Your thoughts?

[Bfglowkey]

That argument or statement applies ( in my opinion) and is used often when discussing common hunting distances: 150yds or less. I would argue that many of us harvest 100 yds or less. The only game I have taken shots at further then 100 are those Aoudads....jittery buggers. So yes, hitting a white tail at 80 yds with a 308 or a 300 RUM vs a 300 BO ( extreme spread I know but the animal will be dead ) the animal cant tell the difference...its dead. Now take that comparison at say 200-300 yards ( now we get into ethical hunting distances etc for some folks) and a BO is an inferior choice for that same whitetail. The disparity and need/desire for larger capacity cases behind the same diameter bullet is a factor of distance and intended use.

I personally don't worry about energy on target for my practice/target rifles....its moot. As long as it gets there accurately so I can puff my chest out at my mad groups. For hunting, energy on target is vital as you push past common hunting distances to ensure you do not loose the animal or worse cause it to suffer any more then possible by using a weak round that wounds it regardless of shot placement.

[mxsailor803]

Mine is actually pretty simple. Pick the gun/cartridge you are most accurate with that has enough ability to down down game ethically. I prefer not to get beat to death due to heavy recoil rifles. I also don’t want to carry around a 10lbs plus rifle.

[std7mag]

More better, more faster, more power has been the mantra for a long time now.

Needed?
Yes and no.
6.5 Grendel is making hits on target at 1 mile.
With it's low recoil it's easy to make into a decent target cartridge. (Note, good bullet development has given better BCs which majorly factor into the equasion)

But at 1 mile the 338 LM, 408 and 375 Cheytec, and 50 BMG are all excellent target rifles.
I don't think i'd use them for 100 yard IBS or UBR matches though.

Then there is performance for dangerous game.

What most people don't look at as far as hunting is the minimum velocity needed to ensure the bullet has enough energy to perform properly.
Most (not all) bullets need 1,800 fps to ensure expansion. (We are talking rifle hunting bullets here!)
With that criteria, i can safely have the bullet perform from my 284 Win to 600 yards.
While the same bullet from my Rem Mag gives me almost 900 yards.

[jmr40]

It's about impact velocity and the bullets design parameters. MOST common bullets are designed to give good penetration and expansion if they impact between about 1800-2800 fps. Those numbers aren't carved in stone, different bullets and manufacturers will vary some. If they impact too slowly they don't reliably expand. Too fast and they may expand too quickly and not give enough penetration.

Some premium bullets are harder, meaning they stay together better at faster impact speeds, but those also need faster impact speeds on the low end to expand. A bullet that stays together at 3500 fps may need a minimum impact speed of 2200 fps to expand.

Others are designed to expand at slower speeds, those are typically meant for 30-30 class cartridges.

The primary reason for magnum cartridges is to keep bullets above the 1800 fps threshold farther down range. If a 30 caliber 155 gr bullet impacts at 1800 fps or faster the game animal will be just as dead. The animal won't know what cartridge fired it. The only time an extra 100 fps matters is if you're right on the edge of the chosen bullets capabilities.

If you use good high BC 155 gr bullets a 308 will drop below 1800 fps at around 500 yards. A 30-06, a bit over 600 yards, and something from a 300 WM will do so at 700+.

But you also have to consider impact speeds up close. The 300 WM's MV is going to be around 3300 fps. Unless you're using a premium bullet designed to work at that speed you're going to get a bullet failure. The 308 starts at about 2800 and is still above 1800 out to about 500 yards making it usable over a pretty wide range.

The trend in recent years is to take advantage of modern aerodynamic bullets. By doing so it is possible to start the bullets at a more moderate speed, but still retain usable impact speeds at much longer ranges.

This is an admittedly extreme example but it makes the point. If we fire an old school RN 180 gr bullet from a 300 WM @ 3000 fps and a modern high BC 180 gr bullet from a 30-06 @ 2800 fps the, bullet fired from the 30-06 will be faster than the one fired from the 300 WM at only 75 yards. Firing the high BC bullet from a 308 @ 2600 fps it will catch up to the 300 WM at 175 yards.

[ndking1126]

there’s no impact to the trajectory or to the ability to provide terminal performance on game

If a 308 is capable of killing the intended game at the intended distance, then there's no need to bring the 300 WM out unless you just want to. Dead is dead. 300WM has the advantage of being lethal at longer ranges, shoots flatter, and is better at bucking the wind, but since this isnt a long range hunting forum, the statement "the game wont know the difference" is perfectly accurate for most people who visit this forum.

"The animal wont know the difference" is often used as a counterpoint to our tendency to obsess over some of the numbers on a ballistic table. Look at them too long and they start to paint the differences as bigger than they are. If a bullet can poke through both lungs and/or the heart, it's going to kill the animal. We as a human race have been killing animals well before premium bullets, and magnum cartridges were invented. (I'll reiterate, the farther your shot at the animal, the more cartridge and bullet selection becomes an important factor.. this isn't a long range forum so I'm assuming normal hunting distances of 200 yards or less for most conversations.)

I guess I would the turn the table and ask you want you think you gain with more velocity? I get it... bigger wound channel, may (or may not) put the animal down a few seconds quicker, etc with the bigger, faster bullet. Again, dead is dead. All I see is more wasted meat. I'm not hunting a sheep or elk walking along the edge of a steep hill, so I dont mind them running 50 yards instead of 25. If I was, I would want a big magnum that would punch through the upper shoulder and paralyze it so it would drop right there. But in most cases, that's not a shot I'm taking so there's no advantage to the increased velocity.

[HiBC]

You CAN select your gear for the shot that might present itself 1 % or 5 % of the time.
Or you can gear up for the 90% shot.

And,lets not ignore that maybe 50% of the time,the game will be qute close.

OK,my numbers are for illustration only.

You might have to pack a 9 lb 300 WM on 18 elk hunts before the elk give the 300 WM any advantage over a 7 1/2 lb 308.

Odds are,you will trim less ragged bloodshot meat using the 308.

Shot placement is as much a factor as anything else. The average person will anticipate 300 WM recoil.He MAY have the focus to not close his eyes and cringe. Or,sometimes not.

It might be that a 115 gr Accubond launced at 2800 fps by a 257 R will hit the game within a 3 in circle at 125 yds as the relaxed,confident shooter squeeezs off.

Pick what you prefer. If you give the game a clean end,use whatever works.
Its not my business.

For entry level folks,on elk I'd recommend "Adequate for 300 yds" and cartridges generally in the 270/308/30-06 range.

Deer shots are so varied in range and terrain,its hard to nail down. A 30-30 works.So does a 243.250 Savage,etc. Some folks swear by a 223.

Do you need a 300 WM for a 100 lb Texas White Tail? Thats up to you.

Use a ballistic softwware to actually establish Max Point Blank range if you are of that school. Or,impact velocity.

Some folks might be surprised by the actual results

[ndking1126]

So why when max loads or a small cartridge size increase are discussed is this the common sentiment,

The other possible aspect to that statement is that the OP is often asking if the extra performance of the new cartridge is worth the extra cost.. to which the statement implies that you can pay more, but the older, cheaper cartridge is going to kill the animal just as well for less. Unless you intend to shoot an animal in that extra 75 yards of lethal range that the extra 100fps give you, then the person is saying "no, probably not worth the extra cost."

[44 AMP]

I think looking at the energy numbers at different ranges is a red herring.

Once you pass the amount of energy needed for the bullet to reach the vitals, (and nearly all rounds do this) what more do you gain with more energy? And, for me, talking about shooting game animals at 5,6, 700yds or more is just rubbish.

Where the increased speed of the magnums does show a difference is in drop. Look at the tables, with the same bullet, 100fps more muzzle velocity means (approximately) 1/2" less drop per hundred yards.

Now, this doesn't matter a lot when you know the range, but when you are "guesstimating" the range you could be off by quite a bit and not realize it. THEN the flatter shooting round helps compensate for your error.

Is that worth lugging around a couple more pounds of rifle and buring 15%+ more powder every time you pull the trigger? (not to mention the recoil?)

For some folks, it is, for me, its not.

[Shadow9mm]

If the bullet passes through and buries itself 3ft in the dirt, what good does that do you?

How much energy do you need (400ft lb deer, 1500ft lb elk etc.)
how far are you shooting?

to me all that matters is that I can deliver the energy on target. For me that means elk out to 400yds with my 30-06, plenty good. Plus dumping too much energy, especially too close can ruin a lot of mean.