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Optimum and Maximum Practical Game Weight

9911 Views 39 Replies 12 Participants Last post by  mikmarandola
I have searched the internet for Information on stopping power and formulas and tried to figure a formula to account for explosive wounding. This formula can be found under Hunting Stories, perhaps the wrong place to put it..

As I said before I think the Taylor, Hatcher and Thornily formulas to be among the best. I found a post on a forum claiming the Optimal game weight formula to be the best. I found a ballistic program which whilst calculating a ballistic chart also would calculate Taylor's knockdown number or any other of twenty-six knockdown formulas.

The text attached to the program gave the formulas, plus other formulas to calculate gel wood and steel penetration. It also had a chart for each formula so you could know what was needed for each class of game. When you calculated the number for a deer rifle on Taylor's chart, then calculated the number for almost any other formula it still came out as a deer rifle. So it matters not what formula you use as long as you have a chart to go with it.

I then thought what is the best formula. Going back to what I know.

1/ The 45 auto has a great reputation for short range stopping power. It loses 30ft/sec over 100yds so it doesn't lose much stopping power over distance.

2/ The 30 cal carbine was considered to be a bit marginal when it came to stopping determined enemies.

3/ The 223 Armalite/M16 could inflict terrible wounds (at short range) due to explosive wounding and or an unstable bullet.

I think these guns should be rated 1, 3, 2, or perhaps 3, 1, 2, at very short range. Looking at these weapons using OGW gives 1/ = 41lb 2/ =141lb 3/ = 97lbs.
The advantage of this formula is obvious, a 150lb deer is to much for a 45 auto, or is it.

There were several game weight formulas with my ballistics program. My favourite Maximum Practical Game Weight uses Energy calibre and bullet weight to produce the target game weight. EN x BW x CAL divided by 100
1/ = 341lb 2/ = 203lb 3/ = 111lb if these weights are the maximum you can expect to get a quick kill with a well placed bullet. I then divide by 2 to get what I consider the "Optimum" game weight". The result means (3/ = 56) the Armalite/M16 could be relied on to take down coyotes at over 100yds. If the game is dangerous divide by 4, e.g. You have just been surprised by a 120lb mountain lion at 50 paces you can't rely on a 45 auto (1/ = 85) to stop it with one shot.
I haven't forgotten about bullet types I would multiply the above numbers by Hatcher's bullet chart e.g. 0.9 for FMJ, 1 for LRN. I have read that pointed bullet tend to tumble for these I would use a factor of 1.5 which still doesn't turn the Armalite/M16 into a good deer rifle.
With these and most other stopping power formulas a base ball has more stopping power than a big game rifle. However apples are not oranges and a baseball is not a bullet. The formula I Have for Gel Penetration is:
MOM divided by Cal^2 x 6.625
This gives a gel penetration of .9 inches hardly what is required for an offensive weapon.
As for explosive wounding as far as I know it seems to happen with very high velocity bullets. Perhaps this is already figured in the formula as energy increases with the square of velocity so does the expectation of explosive wounding occur.
After much study these two formulas seem much better than I originally thought.
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I don't agree that you can predict how far a lung-shot deer will run, with anything.

What might be claimed is that the bigger calibers leave a better blood trail, and that is fine with me. Depending on where you hunt that could be a serious issue, or no consequence whatsoever.
Furthest iv seen a good double lunged buck go is about 70 yards. that was with a 30-30 with 170 grain corelokts at 5 yards, on a fairly calm deer. If one never had to worry about having a blood trail, i guess a .223 rem with proper bullets could probably be "suitable" for most anything in the lower 48. Most places that i have seen, where deer hang out also have at least some cover... just saying.
Obviously there are a lot of people using the 223s for huning judging from the amount of Deer bullets made in the calber.
Barnes, Nosler, Trophy Bonded Bear Claw, Winchester all make bullets suitable for Deer.

Natives in Alaska even hunt and kill bears with the 223. Yes, Grizz and Polar

http://shootersforum.com/forumdisplay.htm?f=22

Check out the link they went hunting this bear with a 223
Furthest iv seen a good double lunged buck go is about 70 yards. that was with a 30-30 with 170 grain corelokts at 5 yards, on a fairly calm deer. If one never had to worry about having a blood trail, i guess a .223 rem with proper bullets could probably be "suitable" for most anything in the lower 48. Most places that i have seen, where deer hang out also have at least some cover... just saying.
Well I have trailed lung-shot deer farther than that, at least double on a couple of occasions. Not that I'd prefer to, that's just how it works out sometimes. You never know. Two instances that come to mind were with my .257 Weatherby and .30-06, so it can happen with the bigger stuff too.

We also generally hunt from fixed blinds, which makes a world of difference in having a steady rest. Also, quite a few of the deer that get shot with .22 and .243 cal rifles are does and such being harvested for the freezer. It makes a big difference when you have high density and a season 2-3 months long; you can pass up those marginal shots and go out another day.
Well I have trailed lung-shot deer farther than that, at least double on a couple of occasions. Not that I'd prefer to, that's just how it works out sometimes. You never know. Two instances that come to mind were with my .257 Weatherby and .30-06, so it can happen with the bigger stuff too.

We also generally hunt from fixed blinds, which makes a world of difference in having a steady rest. Also, quite a few of the deer that get shot with .22 and .243 cal rifles are does and such being harvested for the freezer. It makes a big difference when you have high density and a season 2-3 months long; you can pass up those marginal shots and go out another day.
I'm sure if i get to the number of deer you have taken, i will likely have had to trail one 100+ yards too. Good point about the doe's, a small doe or even medium sized doe isnt hard to kill at all. Where you hunt is there access to dogs for following a blood trail?

I just dont think there is many circumstances where a .223 would be a reliable deer killer, at least you would eventually lose some well shot deer. In the situation you describe it would probably be very usefull. I consider the .243 the bare minimum for a good deer rifle, which require very precise shot placement, and it is a powerhouse with 100 grain partitions compared to the .223 rem.

I very rarely get a chance to hunt doe's here, and the majority of the bucks around here are mature, so over a span of 20 deer here, you are lucky to have 3-4 does mixed in with probably 10 mature bucks and 6-7 young bucks, versus somone who is hunting small doe's with the occasional buck. That calls for a different type of cartridge requirement, so i understand why theres such variation.

I know and understand why the .223 rem is used for deer, i just dont understand why people are arguing that it is a GOOD deer cartridge, it most certainly isnt, just because a lot of guys have killed a lot of miniature does. The pic showed earlier looked like a barnes tsx, recovered from a double lung shot deer with no bone hit, if the bullet not exiting being as high qaulity as it was is not indication that a .223 rem isnt a deer cartridge, what is?

Heck id use a .223 rem for pronghorn in a pinch with some good tsx bullets, but **** its no deer cartridge or itd be as popular or more than the .243, dont you think id like to shoot a pop gun and witness bang flops? i dont really ENJOY the recoil. :confused: :confused:
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There is a wide range of suitability between the two extremes of "good" and "bad". I never said the 223 was a bad deer cartridge, but it sure isn't a great choice, especially north of the Mason-Dixon.

Mike, on those deer you've had to track quite a ways after being shot with your 257 and '06...did you eventually find your bullet had penetrated completely, allowing for a blood trail that CAN be followed?

It's easy to say the word, "deer" and forget that you're talking about animals that can range in size, quite a bit. The first buck I ever shot was an old Michigan whitetail that dressed out at 160lbs. The third deer I ever shot was a nice 3x3 blacktail, but he only dressed out at 85lbs. The middle one was a scrawny little blacktail that I never bothered to weigh, but if he had been a boy on the playground, he would have been picked last...I'm guessing 60lbs, dressed.

To put it in perspective, my dad shot a blacktail just a few hundred yards away, with a 30 carbine. His shot was aimed behind the ear, but hit the deer a little lower down, in the neck. It only ran 200 yards...STRAIGHT DOWN HILL! :D Dad cussed that deer, and that gun, swearing he would never again use it on anything bigger than a jack. At the same time, he harvested more than a handful of deer with a 22...Win Mag. The times were tough but the shot conditions were ideal: He was a crack shot back then and hitting an object the size of a brightly lit quarter was no trick at all. And our family ate well for a week or two. Does that mean the 22WMR is a "good" deer rifle? Of course not! Just because a given cartridge "will" kill a deer, does not mean it is a good choice to consistently do so, under a wide variety of conditions.

I find it a bit absurd that this topic even has to be debated, really. So, I'll shut up, now.
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I agree with you Broom 110% ...

a .243 is plenty, a .223 is not. and anybody that really believes otherwise is not well informed.

you can lead a man to knowledge, but you cannot make him think......
I agree with you Broom 110% ...

a .243 is plenty, a .223 is not. and anybody that really believes otherwise is not well informed.

you can lead a man to knowledge, but you cannot make him think......

To ignore the many Deer taken successfuly each year with the 223 is to ignore the facts

If the 22 center fires were not used by so many each year, then there would be no market for the "Deer" bullets made for them by MANY manufacturors, including but not limited to Nosler, Speer, Barnes, TBBC, etc.

Those that refuse too admitt that the 223 works, makes me wonder if they have ever seen one used on Deer with a proper bullet and shot location (any where through the chest acavity
I agree with you Broom 110% ...

a .243 is plenty, a .223 is not. and anybody that really believes otherwise is not well informed.

you can lead a man to knowledge, but you cannot make him think......
That's rich. How do you explain the multitudes of deer taken every year with the .223? It must be adequate.
My point was.

Gentlemen seems my thread has stirred up a hornets nest.

To Broom_JM. I am not offended, rather complimented, for me mathematics can solve any problem how else did America put a man on the moon.

To jwp475 I did not say a 45 auto would not stop a cougar, I said could not be relied on. I am British (Scottish) I have fired .303/.308/7.92 military weapons at an army organised shoot. The only pistol I fired was a Remington 44 cap and ball revolver.
A pistol is a back up weapon for someone like a radio man whose main job is communication, killing the enemy is usually done by others in a platoon. As a back up to any hunting rifle the 45 auto would be high on my list of possible choices.

To the others who made replies: The point of this thread was to offer a stopping power formula which would model reality, i.e. what actually happens when Game (or people are hit by bullets) different weapons can then be rated and chosen for the job in hand. I did not mean to start an argument on how good a deer rifle the 223 Remington is. As broom_jw says the rounds I chose to compare were military rounds, they were chosen because these weapons have a reputation for stopping power or the lack of it.

I have followed the thread and been surprised to read that the 223 was chosen as a weapon to wound our enemies, not kill them. American Indians were I think rather good at killing their enemies, even if to prove their bravery they would sometimes hit an enemy with a coup (coo) stick. Are we to go the same way? I always thought one reason the 223 was chosen to allow the soldier to carry twice the number of rounds.

To mikeG I have some thoughts (ideas) on the right bullet but feel I would be better to start a new thread.
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To Barkbuster: I don't think it is legal to use dogs for trailing up deer in Texas anymore. Not sure but I don't have one suitable, anyway.

To Jason: One very long tracking job had the bullet stop on the opposite side, barely poking out. The only blood was likely from the entrance hole. The other was a through and through shot. So, both can happen. I'll take an exit hole and blood any day though.

To the original poster: I think this illustrates why the formulas are all pretty well useless in the real world. There is just such a variety of experience under what might be near-identical conditions. One animal drops dead, another goes many hundred yards, etc., etc. No formula can explain such a thing.
The 223 was not chosen to wound the enemy, it was chosen as you correctly stated to be able to carry more ammo and be controllable to fire in full auto mode. With proper bullets the 223 is effective on the battle field and in the Deer wounds and the facts support this. The short barreled Military weapons with the reduced velocity and the longer engagement distances (300 yard and beyond) in Afghanistan is where the 223 is lacking and glaringly so

Math can indeed solve all problem if one understands the math and all of the science involved in wound trauma incapacitation

Duncan MacPhearson has produced a math model that works and was proven by Dr. Martin Fackler

{Moderator edit: Sorry, no copyrighted materials may be posted without written permission of copyright holder. See the policy change thread here. Sorry for the inconvenience, but you can provide a link to a page selling the book if you like.}

Duncan's model is for handgun cartridges and velocities. The added velocity of rifles add other dynamics to the equation, scuh as greater amounts of hydraulic pressure that also aids in the size of the wound channel as well as secondary projectile wounding
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How long before this useless argument ends????????? :confused:
I've had nearly all my deer fall within my sight, so the lack of a blood trail is irrelevant. I know of a failure to exit with a 165 gr btsp 3006, at 65 paces, with 2850 fps on a little 80 lb Ark buck. It ran 80 paces and was nearly lost, at dusk, in heavy brush. Jamie had to run to town and get 3 buddies with flashlights to find it.
How long before this useless argument ends????????? :confused:
It'll probably end about the time one of these guys has a trophy buck move, just as they squeeze the trigger, or when they find out their scope had come loose, shifting POI a few inches. As the deer of their dreams runs off to die a long, slow death, with little chance of tracking it successfully, because those tiny bullets just don't allow for much wiggle room, these guys who are willing to operate on the thinnest margin of acceptable performance will find out what happens when ideal turns into marginal.

Wisdom is the fruit of failure, by and large...you make enough dumb mistakes and you learn to think things through, allowing yourself a margin for error. When you're young and cock-sure, you'll ride the razor's edge, but after you cut yourself enough times, you smarten up and realize things don't always go just as you planned. In fact, you start to see things clearly and grasp that they RARELY go by-the-book! That's when these guys will figure out that you don't hunt with just barely enough gun...you carry something that will get the job done, and then some. You chamber a cartridge with a bullet that will work when everything is textbook AND when you, or providence, encounter a far less than ideal situation.

Sadly, a lot of people refuse to learn by anything other than their own mistakes; least of all the wisdom, conventional or hard-earned, offered by others. In fact, the most hard-headed guys will push the envelope as far the other direction as possible, just to prove...well, to prove their elders right, by and large. I should know...been there, done that, got the bad memories to prove it.

FWIW, Ken -- These are the "pointless" arguments that should be argued. No, I won't convince jwp to err on the side of caution, or that discretion is the better part of valor. He'll be convinced he's right until backed into a corner and the good Lord delivers an incontrovertible lesson. That doesn't absolve me of the right (and responsibility?) to do my best to shed a little light on the subject, does it? I sure hope not, because, just as I won't shy away from testifying about the Way, the Light, and the Truth, I will not stop sharing what I have learned about other things close to my heart.

P.S. I'm a man of God first, and a man of science, second. Math might get man to the moon, but it is only by grace that he may be redeemed. There is no formula for calculating what a given bullet will do because there is no way to quantify the "spirit" God has endowed his creation with. Hunt long enough, as many of us here have, and this too, will become evident. Hunting's way more fun than MATH, anyway! :p
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Well, if the thread has a life of its own - my .02.

Although in my state the legal minimum caliber for big game (deer, elk, bear, etc) is ".223 centerfire" (which includes the .22 Hornet), I'm personally not about to take either my .223 Remington or .22 Hornet on such a hunt. The .243 caliber will be the minimum for deer/antelope, while the 6.5mm's will do for deer. Elk and bear require a 7RM minimum.

Going hog hunting, TPV has convinced me to take the 7RM and 7 Dakota with 175 gr SP bullets.
In my ridiculous state (Indiana) minimum bore size for a deer rifle is 35 caliber! Well, unless your barrel is short enough to be legally considered a handgun, in which case the minimum is .243" In the rifle, the case can't be more than 1-5/8" long, but in a handgun, you can shoot a 300WM, if you like.

Talk about things that don't make sense, eh? :)
The rules are often ridiculous for the same reason a stopping power formula to choose your gun and ammo can't be universally agreed on, whether for game or for social purposes. It's the individual factor. How much gun the individual can shoot accurately; how much gun the individual game animal needs to be stopped humanely; what the individual circumstance of range and shot angle are likely to be; how much gun is too much from the standpoint of meat destruction. You're always striking a balance.

I'd rather see a kid use a .223 he can hit with than a .308 he can't. If that's not acceptable for what you are hunting and the kid can't shoot anything bigger very well, then he needs to grow another year before hunting something that size. The ability of the cartridge to do damage is seldom the only consideration. Thus, the formulas are unable to stand alone.
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Spot on Uncle Nick
Uncle nick I Don't know what all the letters mean but you don't get to be a master instructor at anything unless you are an expert.
There is nothing in your last post I don't agree with.
I thought the Maximum Practical Game weight was one of the better stopping power formulas as it had no need for an animal chart. I did mention in my original post that no mater what formula used a weapon classed as a deer rifle came out as suitable for deer. To be blunt no rifle recognized as being a good deer rifle turned up on any chart as an elephant gun.
I never thought about the meat which a bullet might destroy.
So because you are an expert and I mean that in a respectful way. Please comment on this.
I think stopping power formulas are not The problem.. I think people use the wrong bullets for the job, for example fast expanding hollow point bullets on game which requires deep penetration. Combine this with the claim " I got a chest hit " which turns out to be a gut shot and it gets easy to say stopping power formulas are rubish.

I had a friend when I was a boy who said he could shoot rabbits at 25yards with his 22 air rifle (11 foot pounds) and telescopic sight. His claim was he could shoot them in the eye. I never saw a rabbit further than 15 yards and they were always running.
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