Bullet weight 'effectiveness'?


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ExAgoradzo
September 21, 2012, 12:06 AM
This may or may not be the best place for this question, but here it goes:

This is what is listed on the box:

.30-06 Fed Prem Ammo 165 gr (Barnes Triple-Shock)
Muzzle 100 yards 200 yards
2870 ftlbs 2405 2000

.30-06 Fed Power shock 220 gr (Speer Hot Cor SP)
Muzzle 100 yards 200 yards
2815 2195 1690

Now, my understanding is that someone would buy the first because they wanted something to take down the little black tail deer we have out here or some hogs while someone would buy the second because they wanted to take down some elk or moose. But if you just go by 'energy' the smaller bullet has the larger beat. (I noticed BTW that this is also true when comparing the Corbon 460 gr 45-70 bullets against the smaller 325gr Hornady GMX.) Now, I understand that the faster the bullet goes the more energy it will have, but then why go with the bigger bullet that won't fly as fast (given the same cartridge)?

Why use the bigger bullet?

Why is the 220 gr bullet better to take down a elk than the 165gr? (Also, there must be more to the fact that 'bullet placement' is always key...but assuming a correctly placed bullet, why wouldn't I take the one with the higher energy (but smaller weight) to knock down whatever I'm hunting?)

Perhaps the answer will have to do with penetration, but again, my question will be, wouldn't the bullet with the better design and greater energy (but smaller weight) give better penetration?

Thanks for your help on this, you guys have been so helpful in helping me sort out many things...I appreciate your help.
Greg

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Andrew Leigh
September 21, 2012, 02:56 AM
Assuming that shot placement is equal you can take all the big stuff with both.

Where the Barnes is good is on penetration despite hitting bone, they crush bone and will drill into the vitals. On smaller softer game the barnes at times can drill right through leaving little blood trail when wounding an animal (lung shot etc.). The petals on the barnes get razor sharp and cut like a knife. You also cannot make them much heavier as the bullet length will not allow you to have the required powder load or seating depth. By and large the bullet will stay intact with all 4 petals and weight loss would be no more that 5%. The have a reputation for accuracy.

The 220gr is for me a standard jacketed bullet with a lead core, there will be more fragmentation on penetration and the weight loss will be greater. The bullet will not penetrate as far as the barnes but will penetrate enough. How dead is dead? The fragmenting bullet allow pieces to penetrate other vital organs but remember these are small fragments. The flat base makes this an accurate bullet out to 200m.

A slower heavier bullet generally cause less meat damage, in this case they are the same speed so no gain either way.

Where I come from you would use the Barnes for the bigger stuff as it has the capacity to drill through bone, some of the bigger stuff has massive bone structure. You also never know if they are about to move as you let the trigger go. I would rather shoot an Eland with the Barnes. Although with careful shot placement both will work, the Barnes has more insurance factor.

Finally on the Federal site under Resources and then videos find one that say's Bullet, Bullet Breakdown Video, should explain it well with pictures.

interlock
September 21, 2012, 08:23 AM
in my opinion the bullet with the highest sectional density will penetrate further all things being even.... but they are not

W.E.G.
September 21, 2012, 08:39 AM
Any critter that is so big that it "needs" an extra-heavy 30-06 bullet to kill it has plenty of meat to "waste." Think rhino or cape buffalo.

The 30-06 was originally designed as a military caliber shooting a 150-grain projectile.

If you are really worried about ANY bullet fired from a 30-06 fragmenting or failing to penetrate, you might want to look at a bigger gun, and not a heavier bullet in the 30-06.

The 30-06 loaded with quality hunting bullets in the 150-180 grain weight class will easily kill any animal on North America with one shot to the vitals from any angle.

Once you start getting over 200 grains, I have to wonder whether the twist-rate of an ordinary 30-06 barrel will properly stabilize such a bullet.

jmr40
September 21, 2012, 10:45 AM
This is a complex question, with no simple answer. The way the math works bullets that are faster and lighter show more energy than heavier slower bullets. But ft. lbs of energy never killed anything, broken body parts kill stuff. But energy numbers are not completely irrelevent, they can help predict bullet performance if you understand all the factors involved. Bullet placement, expansion and penetration are the key factors.

Perhaps the answer will have to do with penetration, but again, my question will be, wouldn't the bullet with the better design and greater energy (but smaller weight) give better penetration?



Generally heavy bullets hold together better and penetrate better. Lighter bullets tend to break apart when they hit larger game. The Barnes bullets are fairly new to the scene and are one of the exceptions. They tend to give penetration equal to one or 2 weights heavier. So in this case the 165 Barnes should actually be close to the performance you'd normally expect from a 180-200 gr bullet. If I were hunting elk or moose I'd have no problems with a 150 or 165 gr Barnes bullet. If I were hunting that game with conventional bullets I'd move up to 180-200 gr bullets.

A 220 gr RN bullet is not a good example, but heavier bullets are actually better for longer ranges than lighter bullets. While a 150 gr bullet leaves the muzzle faster, and might have more energy at the muzzle. It also slows down faster than the more aerodynamic .30 bullets in the 180-210 gr range. Those heavier bullets start slower, but because they are more aerodynamic, will reach a point down range where they are moving faster than a 150 would be at that range and have considerably more energy. They are also less effected by wind.

This is also true with the 45-70 bullets you are looking at, just on a different scale. You also have to remember that old school rounds such as the 45-70 work much differently. The energy numbers are more accurate in predicting how well modern high velocity bullets work. Slow heavy rounds like 45-70 show very low energy numbers, but get their penetration from using heavy bullets with lots of momentum. They don't really need to expand much, because they are already so large Modern bullets get their penetration from high velocity and tougher bullets that hold together and expand. Both ways work equally well, just very differently.

The Barnes bullets in any weight are good bullets at reasonable ranges, but are a poor choice for longer range work. Conventional bullets give good expansion when they hit game as long as they are still moving at 1600-1800 fps. If a Barnes bullet impacts game at speeds slower than about 2000 fps they may not expand at all. Just passing through like a military FMJ bullet.

Just remember, placement, penetration, expansion. Those are the 3 keys to killing stuff. There are several ways to accomplish this and there is no simple math formula that can accurately predict what works best.

GJgo
September 22, 2012, 12:12 AM
I'd put a 30-06 w/ a 165gr TSX against any Elk that walks, just put it in the boiler room.

Certaindeaf
September 22, 2012, 12:16 AM
Dang, that 220 is cooking. I don't think I remember them going that fast back in the day.
Those are what you use on the big griz, if that's all you got, back in the day.

powell&hyde
September 22, 2012, 12:29 AM
Your right Certaindeaf, the figures ExAgoradzo posts put the 30/06 220gr into 300 weatherby category. I'm sure something was misread.

ExAgoradzo
September 22, 2012, 12:41 AM
30-06 220 gr Speer Hot Cor SP Federal Power Shock
Velocity Muzzle 100 200 300 400 yards
2400 fps 2120 1860 1620 1410
Energy 2815ftlbs 2195 1690 1285 975

This is taken right off the back of the box. If I misrepresented, this is the fuller description.

Greg

Certaindeaf
September 22, 2012, 12:45 AM
Ah. I see now

ExAgoradzo
September 22, 2012, 02:04 AM
The Federal video was interesting.
http://www.federalpremium.com/videoplayer/default.aspx

I had heard, and was hoping for confirmation here, that in past years the heavier bullets were more popular because the ability for the bullet to stay together was not as good but with the newer bullets speed became more important.

It was interesting to me to see the Barnes out penetrate all of the other bullets, even (especially?) with the cow femur.

Thanks for your comments guys. I love learning about this stuff.
Greg

CraigC
September 22, 2012, 04:24 PM
Why use the bigger bullet?
Maybe, just maybe, if enough people ask this question and seek the answer, shooters will finally figure out that perhaps energy is not the best gauge of a cartridge's effectiveness.

ExAgoradzo
September 22, 2012, 08:05 PM
CraigC, I would love to hear your thoughts on this because I am admittedly clueless.
Greg

GJgo
September 22, 2012, 10:49 PM
For hunting, the bullet & the game determine the weight & speed. Ballistic tips & Amaxes frag if they go too fast or hit bone. Barnes don't open up if they go too slow. Etc. & so on. At the end of the day get the animal to bleed out & you have steak.

To the OP, don't you live in the condor zone? If so no lead for you, so it becomes an easier decision.

ExAgoradzo
September 23, 2012, 12:23 AM
Yes, this is condor zone: hence, I'm not really worried about the 165's working on little black tails or even the hogs: they've worked fine for years here. But the question was born because standing in Cabella's in UT I got to thinking about the larger weights.

The theory I've been working with is that if I needed a bigger bullet (say a 225 grain) it would be better to go with the 338 WinMag b/c that is what it does best.

So, for the moment, I'm working under the theory that variety is the spice of life and hence the large variety of weights for the different calibers.
Thanks again,
Greg

1911Tuner
September 23, 2012, 06:26 AM
Maybe, just maybe, if enough people ask this question and seek the answer, shooters will finally figure out that perhaps energy is not the best gauge of a cartridge's effectiveness.

This.

It's long been my observation that if you need more killing power, what you need is more bullet rather than more velocity...which serves mainly to flatten trajectory. Energy is only one part of a complicated equation.

helotaxi
September 23, 2012, 12:29 PM
in my opinion the bullet with the highest sectional density will penetrate further all things being even.... but they are not
That's fact, not opinion.

The issues with that are two-fold however. Velocity has to be the same and the bullet has to deform the same. In the same caliber, a bullet with a higher sectional density, by definition weighs more. Fired from the same gun, a heavier bullet will have lower velocity than a lighter bullet so it is difficult get velocities the same without comparing different cartridges or different ranges. Also, the bullet has to expand at the same rate. This is essentially impossible unless neither bullet expands at all. As the bullet expands, it typically sheds some weight and the frontal area increases. Both of these decrease sectional density and reduce penetration, but deliver energy to the target. That's the tradeoff there.

Penetration is a factor of velocity and sectional density and both are variable. Penetration is inversely proportional to the rate of change of the sectional density and the rate of change of sectional density is proportional to velocity with a conventional expanding bullet. That means that a high velocity bullet will often expand quickly demonstrating a high rate of change in sectional density and a reduction in penetration. This is where controlled expansion, bonded core, dual core and the like come into play. By slowing the rate that sectional density changes or ensuring that it only changes so much, good penetration can be assured while still allowing some expansion to deliver energy to the target.

Simply delivering energy to a target, especially when we're talking about a large game animal isn't going to kill it. If energy delivery was all that mattered, you would want the most frangible bullet available delivered at the highest velocity possible because the bullet would essentially detonate on impact and deliver all its energy to the target. This almost perfectly describes a varmint bullet and cartridge which most all agree is a great recipe for creating a vicious wound on a big game animal without rapidly, if ever, killing it. To put down a big animal, you have to get to the vital organs and thus, penetration becomes an essential part of the terminal performance equation.

Now let's look at your specific question. When basic "cup and core" jacketed bullet were all that was out there, shooting the heaviest bullet possible made sense because having excess sectional density combined with the reduced expansion from the lower velocity was really the only way to ensure adequate penetration over the widest range of shot angles. The good news today is that bullet technology has come a long way. The Nosler Partition changed the game forever when it allowed for the best of both worlds with a lighter bullet that could be fired at high velocity that would hold together and penetrate while still expanding enough to dump energy on the target. Bonded and monolithic bullets are a further expansion of the idea. The bottom line is that these days you don' t have to go with a heavy bullet of archaic design to ensure adequate performance on the largest game. A lighter weight bullet of modern design will get the job done just as well if not better.

Final thing to consider is required, or available, range. Nosler in particular is very good about publishing the velocity required for the bullet to perform as advertised. With that piece of knowledge and the ballistics of your rifle and cartridge combination, you can determine your max effective range. While in reality, most people are limited by the range they can hit the target, a certain well accomplished and practiced group are limited by the range at which their bullet retains enough velocity to reliably expand. These are the guys that Ultra Magnums and the like are made for. If you know for a fact that you are capable of shooting an animal cleanly at 700yds from a field position and the hunting you are doing might require such a shot, then you calculate backwards from the the required bullet performance velocity at 700yds to determine the muzzle velocity that you need to make that happen. From there you find a cartridge that can deliver that velocity. In a similar vein, if you have a certain cartridge available you calculate the range at which your bullet goes below its designed expansion velocity and you limit your shots to that range or shorter.

helotaxi
September 23, 2012, 12:32 PM
Dang, that 220 is cooking. I don't think I remember them going that fast back in the day.
Those are what you use on the big griz, if that's all you got, back in the day.
Hornady publishes loads with a 220gn round nose up to 2500fps from the .30-06. His initial post was energy, not velocity.

ExAgoradzo
September 23, 2012, 03:11 PM
Thanks Helotaxi,
I'm going to reread that some more to digest it better. I may have a follow up question.
Greg

FROGO207
September 23, 2012, 08:49 PM
I always figured it this way:

If you take a soft ball and throw it at a certain speed and have someone catch it that can measure the impact and record it in foot-pounds of energy. Then take a candlepin bowling ball and throw it at the same speed and have the same setup catch it what would be the recorded energy. IIRC the soft ball would slow faster (smaller mass) and impart less energy on the target when it hits. I sure would be wanting to catch the softball and not the bowling ball if thrown at me.:) I use this example of different weight and similar sized objects instead of bullets for comparison.

Then you enter the expansion factor at velocity required to do the job and it means more on target performance.

Coltdriver
September 23, 2012, 09:44 PM
Its an interesting question and there's more to consider.

The bigger bullets usually give you a rifle with a shorter effective range. But for the speed you have given for that Speer bullet it would very closely match the ballistics of the lighter round. I ran it thru Hornadys ballistics software and it showed about a 7 inch drop at 300 on a 200 yard zero.

A lighter bullet usually gives you greater effective range, with a fast 150 grain bullet you can shoot out to 300 yards pretty easily. Say a few inches high at 100 yards and a few inches low at 300 yards. That Barnes is 7 inches low at 300 yards if you zero for 200 yards.

The problem with the Barnes is that because they are all copper they are longer for a given weight. And that length may be too much for your rifles twist. I would not be surprised if the Barnes were longer than the 220. You may also have this problem with the 220.

What is the twist of your barrel?

gamestalker
September 24, 2012, 12:38 AM
This is an interesting thread to me. I have always been one to reload with the mid weight bullets and then push them as fast as I can using a slow burning powder. My purpose in loading with the lighter weight bullet is that I know I can get as much kinetic energy, foot pounds, or knock down power, as it were, with say a 130 gr. @ 3400 fps (7mm RM) as can be achieved with a heavier 165 gr. bullet, and it is going to produce better ballistics for those long shots as well. I also load for the 30-06, and for that cartridge I will run with 155 gr. to 165 gr weights.

I have been taking elk and other large game using this mind set and have not had a problem putting them down, even at extended distances out past 500 yds.. If the bullet is a well contructed projectile, which Barnes is, you will retain a good amount of projectile. But because Barnes are so long, being that they are solid copper, you are probably going to have a rate of twist issue at those velocities. I personally prefer a Speer for good integrity. But there are a few other really good bonded core style bullets on the market these days. Now there is deffinitely a point in which to much velocity, with to light a projectile will work against you. But in the mid weight class for a given cartridge, one can attain better ballistics, equal or better kinetic energy, and all the necesary penetration needed to punch through the shoulder of your quarry.

An example of what I'm referring to would be an elk I shot with a .270 win back in the 1980's using a 130 gr. Speer Hot Core BT at over 3150 fps MV. I shot that elk from the butt and ran the bullet straight up the back bone, punching through every single vertebra, and the bullet came to rest at the base of the neck, buried in the neck bone. When I recovered the projectile and cleaned all the bone off, it had retained 91% of it's original weight, and was in a nice mushroomed condition. I killed another elk with the .270 win from over 500 yds. also using the Speer 130 gr. BT, and that shot placement was through the shoulders, both shoulders. With the 30-06 I have had simular results using the 155 gr. and 165 gr. weight bullets on elk and deer. So my opinion is to go with the 165 gr. and some IMR-4350, RL19, RL22, or any other nice slow burning powder that will get your velocity up there and group well.

An example of energy I have tested is, I loaded up a 162 gr. 7mm RM RL22, and a 130 gr. RL22 and fired them both at a 1/2 piece of plate steel. It doesn't matter what grade the steel was, because I used the same piece of steel for both loads. The 130 punched straight through, the 162 gr made a large dent and crater. I recovered the the 130 gr. from a 5 gal. bucket of water the steel plate was resting against. And although there was a .510" steel plug in the bucket, rather than a projectile, it clearly demonstrated how much more effective the gain in velocity was v.s. a heavier projectile in terms of energy from 200 yds..

I've heard a lot of reloaders question what degree of accuracy I'm getting with such high velocity loads with medium weight bullets. But at 200 yds. I can get 1" groups without much effort, even when pushing them at those high velocities, or as fast as I can without pressure issues.

GS

ExAgoradzo
September 24, 2012, 01:16 AM
I have a Rem 721 made in April of 1951. I have no way of knowing what the twist is unless one of you guys can tell me how to do it. I would be interested in knowing...

Could you somehow do it with a cleaning brush following the rifling???

Greg

Ridgerunner665
September 24, 2012, 01:24 AM
The twist is 1 in 10"...standard for 30-06...and it will stabilize any "normal weight" (up to 220 grains) .30 caliber bullet you want.

The rate of a bullets spin doesn't slow down as its forward velocity does...centrifugal force keeps it going, there is very little resistance on the bullet to slow the spin...just what little air the rifling marks catch.

Theoretically,
You could fire a bullet straight up...it would go as far as the velocity would carry it, be stationary for a split second (still spinning), then fall back to the ground...still spinning.

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