Shooters Forum banner

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.
See less See more
1 - 3 of 40 Posts
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.
See less See more
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.
See less See more
1 - 3 of 40 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.