Okay, I just entered in some numbers, trying to crunch out what weapon would be the best at varying ranges and whatnot. To be honest, I based the range and damage capability of each round off of the comparative M1 Garand round, which was a 11.2 gram round fired at roughly 820 m/s, reaching a maximum effective range of 1000 meters.
As it turned out, the 5.56mm got an effective range of 500 meters, the 6.5mm grendel round got an effective range of 700 meters, and the 7.62mm x 51mm NATO round got an effective range of 850 meters. All of these, rough estimates of course. It turns out to be pretty close to real life statistics so, I figured the effective range of the 6.5mm Grendel round (which is listed as being the same, but preforming better than the 5.56mm round) was pretty accurate.
I then began to crunch a few numbers to see how well each weapon would preform at the minimum effective range of the lowest effective range of all the weapons (In this case, 500 meters for the 5.56mm weapon). I derived a number from this that would would proportionally compare damage ratios solely based on effective range distances (Which in the end cuts out a s**t load of variables). Not completely out of tune, I then compared the damage ratios, using both momentum and energy (multiplying them, assuming that all the bullets were of the same type and were the same used by NATO) and got 0.67760, 1.68510, and 2.67330 in raw Ratio analysis of the 5.56mm, 6.5mm, 7.62mm round respectively.
I think calculated the number of raw rounds could be carried without magazines (I.E. just raw bullets) for 22.5 lb, which was 1000 rounds of 5.56mm ammunition. Using the basic calculation that you can "Carry twice as much 5.56mm ammunition as 7.62mm ammunition" (Even though in some cases it's slightly more an in other's slightly less) I then began to proportionally analyze the 6.5mm grendel round in comparative weight to round analysis, which brought me to the conclusion that you could carry 500 and 870 rounds of 7.62mm and 6.5mm rounds respectively compared to 1000 rounds of 5.56mm ammunition.
I excluded a number of variables; including accuracy, weight of the weapon, recoil, terminal performance, and while I did not exclude reliability, it turned out to be negligible in reality (although the same would not be true if the weapons were tested in different environments, but this was essentially a clean room). I felt I could exclude accuracy becuase it would provide certain weapons with an inflated unfair advantage in mathematical analysis, becuase weapons of equal performance with different rounds should be compared in the spirit of the round testing, and becuase all the accuracy information presented that the weapons were reliable enough to hit a man sized target out to 500 meters reliably. I excluded the weight of the weapon becuase in my studies, comparative 7.62mm weapons and 5.56mm weapons (6.5mm being used in 5.56mm weapons) were of roughly the same weight per gun (although not the same per magazine), making the weight negligible. I excluded recoil due to the fact that I was testing the capabilities of specific rounds without worrying about training to use such rifles, and also becuase most modern 7.62mm x 51mm rifles are capable of controlled low recoil fire and an AR-10 uses the same proportional gas method as the AR-15, making it, as proved by the Newton's second law, have the same recoil as a 5.56mm round (of which the 6.5mm is considered to have the same recoil of the 5.56mm, making it negligible as well). I removed terminal performance due to extreme differences in ballistic coefficients and the fact I was only testing effective ranges and below. And finally, the reliability and likelihood to jam in a "Clean Room" was found to be irrelevant, and while calculated, pretty much unimportant.
Secondly, I did two series of tests to determine the capabilities of the weapons.
For the 500 meter test, I multiplied the total number of rounds (to show what a single soldier could do), by the damage performance, by the reliability, and finally by the abilities at effective ranges (1, 1.4, and 1.7 for the 5.56mm, 6.5mm, and 7.62mm rounds comparably).
For the CQB or 100 meter test, I eliminated a few of the previous variables, and multiplied the total number of rounds by the amount of rounds per clip/RPM rate (which ironically roughly translated to the RPM rates for the rifles, in terms of ratio, eliminating that variable) multiplied it by the damage performance and then multiplied it by the reliability.
The results I got were purely based in RATIO analysis, with the number themselves being irrelevant, only the ratio when compared to the other numbers. The results I got were somewhat astounding and seemed to match, in my mind, what the general "Say-so" of the rounds are; that is 5.56mm is a light-weight low power round, the 6.5mm is an intermediate, and the 7.62mm is a heavy high powered round. In hindsight, the primary reason why the 5.56mm x 45mm NATO preformed so poorly in the 500 meter test was due to poor terminal performance, were as reason the 7.62mm x 51mm NATO preformed poorly in close range 100 meter combat was due to the lower volume of fire. The reason why the 7.62mm preformed, over-all, in the end, better than the 5.56mm round despite it's poor performance in the CQB category, was due largely to it's performance in the long range category, this most probably becuase it carries an excessively higher amount of energy than the 5.56mm round does (nearly twice as much). The reason why the 6.5mm did so spectacularly in both arenas was due to it's intermediate capabilities. The round basically was 90% as efficient in removing targets at long ranges compared the 7.62mm and 115% as efficient at removing targets at close ranges compared to the 5.56mm in terminal statistics. While it's potentially possible to presumably equal out the ratios to both 105% in both categories, I was satisfied with the results. In complete terminal statistics, I was able to reliably justify that the 6.5mm round outpreformed the 5.56mm round by being nearly 155% more efficient at both duties, and out preformed the 7.62mm by being nearly 128% more efficient at both duties. While different variables could have resulted in different statistics (for instance, removing both a long range and short range comparison, and disregarding the killing power of the rounds), the over-all comparison seemed to result in an over-all accurate set of Data. In other words, a large amount of variables were isolated, including user skill, environmental factors, true reliability (in the environment), terminal ballistics and slight differentiations in weight and recoil (which proved to be negligible in the end).
500 meter Performance 5.56mm- 660.96- 29.28% of the 7.62mm
7.62mm- 2257.31- 100% of the 7.62mm
6.5mm- 2045.68- 90.6% of the 7.62mm
100 meter Performance 5.56mm- 2575.18- 86.7% of 6.5mm
7.62mm- 1663.95- 56% of 6.5mm
6.5mm- 2968.1- 100% of 6.5mm
Total Performance5.56mm- 3236.14- 65.4% of 6.5mm
7.62mm- 3921.25- 78% of 6.5mm
6.5mm- 5013.77- 100% of 6.5mm
Due to the remarkably low performance of the 5.56mm round, and to min-max the 5.56mm round... In spirit of the alleged performance of the 5.56mm round, perceived to having all the following capabilities in a single round (which of course it doesn't)- being capable of piercing 13mm (.5 inches) of homogeneous steel as in the M955 rounds, being capable of as being as accurate at the 5.6mm Gw Pat 90 or achieve .72 MOA at 300 meters, having the same over-all make-up and wide-spread use as the M855 Ball, and being as lethal as the Mk 262 5 gram Special Forces Cartridge, all at the beloved "600 meters"...
I got these figures. Which were essentially remarkably low performance from the 5.56mm round, again. The significant number increase from the previous test was mostly from mild improvements in it's long range terminal ballistics, this most probably due to a more accurate, more energetic, and more powerful (5 gram) round. An increase of roughly "30" or a .63% increase in performance at close range performance was noticed, compared to a 6.38% in long range performance. The net increase resulted in bridging a 6.6% gap and resulted in an increase of total performance when compared to the 7.62mm round, although the 7.62mm round still outpreformed the 5.56mm by 6% in terminal statistics when compared to the 6.5mm, this of course compared to the original 12.6% that the 7.62mm outpreformed the 5.56mm. Notably, the 5.56mm got 15.76% of the total 500 meter performance numbers, compared to 13.31% before, or an 18.4% improvement over last time without the min-maxing.
4235.27
500 meter Performance5.56mm- 667.64- 35.65% of 7.62mm
7.62mm- 1872.24- 100% of 7.62mm
6.5mm- 1694.99- 90.53% of 7.62mm
Total Performance5.56mm- 3268.83- 70% of 6.5mm
6.5mm- 3536.18- 76% of 6.5mm
6.5mm 4663.09- 100% of 6.5mm
100 meter Performance5.56mm- 2601.19- 87.63% of 6.5mm
7.62mm- 1663.95- 56% of 6.5mm
6.5mm- 2968.1- 100% of 6.5mm
Here's my blatantly hard to understand Print Screened Excel copy to show you a picture of what I did.