- Education and Science
Tokarev 7.62x25mm vs. m1911 .45 ACP: An examination of Kinetic energy and its relation to object mass and velocity.
7.62x25mm vs. .45 ACP
When I try to compare these two rounds to one another, my imagination invokes two heavy-weight boxers. The .45 which I compare to George Foreman, is a lumbering powerhouse when within range will drop you like a bad habit. The 7.62x25mm I compare to Evander Holyfield , it is a Cruiser weight who can hang with the heavy weights. Somebody simply forgot to tell the 7.62x 25mm that it wasn’t supposed to match and in some ways exceed the much revered, U.S. made .45 ACP.
In terms of velocity, the 7.62x25mm begins where the .45 ACP leaves off, at approximately 1,200 feet per second. Without a doubt the 7.62x25mm is a superior penetrator. What ballistics aficionados tend to argue is “Stoppng Power” which is the ability of a round to stop your attacker. Much of this debate started when men of so called “civilized” societies had to shoot tribesmen repeatedly in order to put them down. Well, “civilized” brains got together and decided that a larger heavier bullet would help them in the civilized endeavor of stopping charging tribesman. So, the debate continues today, velocity vs. bullet weight. There obviously is not nearly as much information about real – life encounters with the 7.62x25mm. There are plenty of real accounts about the .45 ACP, and overall, the consensus is that a big, wide, heavy bullet makes a big wide hole.
Below is an example of bullet trajectory and (bullet drop)
Trajectory and Velocity, stopping power and Conclusion
Trajectory is the path that a moving object follows through space as a function of time. As it pertains to a projectile it can be simply defined as the path a bullet takes from muzzle to target. A bullets trajectory is effected by the weight (grain) of the bullet and the speed at which it is travelling. Trajectory is usually not extremely important in relation to pistol cartridges unless you are hunting at longer ranges, in which case you need to account for bullet drop and wind. Snipers have a third variable, barometric pressure which varies in different locations. I got the following figures by inputting each rounds ballistics at JBM Ballistics an online ballistics calculator. The .45’s 230 grain bullet drops approximately 7 inches at 100 yards. It’s maximum point blank range is 88 yards. Point blank range is when a pistol’s point of aim is the point of contact. At 100 yards the point of aim for the .45 is 7 inches above the bullseye. The 7.62x 25mm doesn’t drop 7 inches until it has reached approximately 200 yards, at which range it is still travelling over 1,200 feet per second! By the time a .45 ACP has reached the 200 yard range it has dropped over 20 inches. I know, I know, who is going to shoot a pistol out to 200 yards. In any case, the 7.62x25mm retains its penetration capability at further range, making it a superior battle pistol for longer shots. This would have benefitted the Russians during WW II against heavily dressed German soldiers with any number of obstructions from magazines, belts etc.
But 7.62x25mm is not a good Defensive round, it overpenetrates!!
If you read any firearms forums or articles about the 7.62x25mm gun enthusiasts point out two consistent features of the 7.62z25mm. First, it has a flat trajectory. Second, it is a good penetrator and can defeat kevlar helmets and body armor. Reason being, as we discussed earlier it is a very fast moving light round. However, what most gun enthusiasts agree on is that the 7.62x25mm round doesn’t have sufficient “stopping power” and that it is more like an ice pick that does little damage and goes in and out. The goal of a defensive cartridge is to transfer most of its energy to the assailant. To achieve maximum energy on target usually a hollow-point bullet fits the bill perfectly. In addition to hollow points, there are new designer rounds that maximize terminal ballistics. Interestingly, on company produces a cartridge for the 7.62x25mm with a 52 grain projectile that moves at over 2,100 feet per second. This means at within the regular range of pistol gun fights…..7 yards you can shoot your assailant with a pistol round that approaches rifle velocity. Unfortunately, I cannot find a non-bias test on the stopping power of the 7.62x25mm round.
In regard to the .45 ACP there are more quotes and sayings associated with it as there are for Confucius. The .45 isn’t a fast moving bullet, but then again the .45 doesn’t have to move fast for anybody.
I cannot find any other ammunition that elicits the kind of response you get from discussing this particular round. Not even the .44 magnum gets the attention that the revered .45 ACP does in the U.S. The .45 ACP was developed in 1904 in a reaction toward the Moro people’s ability to keep charging when shot by the .38 long colt. In 1904 the Thompson – Legarde tests were carried out. These test involved shooting cattle and human cadavers with several different pistol rounds. Although highly unscientific the tests resulted in the conclusion that a pistol cartridge for the military should be no less than .45 inches in diameter.
Stopping Power (Kinetic Energy)
Kinetic energy is very simply the energy needed to accelerate an object (in this case a projectile) to a certain velocity. This energy is transported with the projectile until deceleration at which time this energy is transferred into the object stopping the projectile. Interestingly, when it comes to speed and mass, one can increase the kinetic energy of a projectile by four times, just by doubling its speed. For example, an 55 grain bullet being fired from a rifle at 3,000 fps. Has four times the kinetic energy as a 55 grain bullet moving at 1,500 fps from a pistol. Here is a simple bullet energy calculator that shows the 230 grain .45 and 7.62x25mm energy. The Tokarev’s round has 440 ft. lbs. of energy leaving the muzzle, the .45 has 414 ft. lbs. This means that the Tokarev’s much smaller 88 grain bullet is going to take more kinetic energy to stop. This is only a strength if the 88 grain bullet is going to deliver all of that energy into the target. If you calculate the (un-named companies cartridge) its kinetic energy accounting for a 52 grain bullet moving at 2,120 feet per second the energy rises to 518! That’s a 16% increase! Also, since it is built to fragment on impact more of that energy is going to be dispersed into the target. This company also makes a 65 grain SWAT load that moves 1,800 feet per second and 467 ft lbs. of energy, that still match the energy level of the 7.62x25mm.
Versatility and Final Thought
If I had to pick one of these rounds and it was the only one I could use for anything it would be the 7.62x25mm. With the arrival of modern cartridge manufacturing and designer bullets this round can be used from anything from home defense to varmint and small game hunting. It would be an excellent round for a carbine and could even be used for deer. The .45 simply can’t boast that kind of versatility. The main difference is that there really aren’t any modern platforms to shoot the 7.62x25mm from. I can’t find any research being done with different bullet shapes and loads (not saying it is not being done). There was a 50 grain rifle shaped bullet of an accelerator design that would have been an outstanding varmint and small game cartridge but was discontinued. In closing, I would like to say that I would not want to be on the wrong end of either of these rounds. The .45 is no slouch when it comes to putting down a threat. However, I think we are just beginning to realize the versatility and power of the 7.62x25mm.