There’s news that an Italian company has designed a new projectile that (they claim) will reduce recoil and speed up the bullet without any changes to the rifle itself. How, you ask? By drilling a channel in the center of the projectile and venting gasses from ports drilled in the sides of the bullet. According to the manufacturer these vents will not only act as a muzzle brake but will also make the bullet faster, as the channels are pointed backwards in an attempt to get some extra speed out of the round. I call bullshit, and here’s why:
“Rocket propelled” projectiles are nothing new. Fans of the James Bond series of films may remember a certain firearm from You Only Live Twice that used rocket propelled projectiles instead of the traditional gunpowder and dumb projectile used in firearms. Turns out that was a real gun being designed and produced with the hopes that the U.S. military would pick it up for the Vietnam War, but they were so expensive and inaccurate that the guns were quickly abandoned. The best groups they could get out of the gun was 17 MoA, which is over 1 foot at 100 yards.
One of the reasons that the gyrojet didn’t work is that the forces acting on the bullet after it leaves the barrel weren’t perfect — one port of the rocket engine would often be blocked or the exhaust would be impeded such that the projectile would inevitably fly off course and group worse than a CAI Tantal.
These bullets suffer from the same problem. Even if — IF — their manufacturing process was so accurate and precise that they could cut identical ports symmetrically around the projectile the act of firing the round and gripping it with the rifling in the barrel would inevitably create different sized ports that would vent the gasses in different directions. Even the slightest of imbalances in force would throw these rounds off course, or at least destabilize them to the point where they tumble instead of spin.
And then we get to the recoil compensation argument, which might actually be plausible. As the bullet leaves the barrel there is a fraction of a second where the ports on the bullet are exposed but the base of the bullet is still engaged in the rifling. At this point the expanding gasses driving the round can escape through those ports, but there isn’t enough space for all of the gasses to leave. This, in theory, increases the time it takes for the expanding gasses to leave the barrel and should reduce recoil as recoil is a function of force over a period of time (the longer it takes the gasses to leave the gun the lighter recoil will be). But that recoil reduction period is so brief and comes at such a great cost (reduced accuracy) that it really doesn’t make sense to use this projectile instead of attaching an actual muzzle brake (which will significantly reduce recoil).
In other words, no matter how well these things are made the concept itself is flawed. I think.
The icing on the cake? These are technically “armor piercing” rounds according to the ATF so we’ll probably never see them imported in the US.