This is filled with assumptions that I believe to be true; but please disabuse me of any that are wrong.
Boattailed bullets can take a couple hundred metres to completely stabilize once they leave the muzzle.
I’ve read that one of the major factors in this instability is that the blast of propellant gasses flow around the bullet, remaining laminar for a relatively long period.
Short range benchrest shooters use flatbased bullets because they stabilize much faster and the bullets do this because the gas deflecting off the flat base interrupts the powder gas flow along the bullet.
Now if this stuff is true, wouldn’t barrel porting work to decrease groups sizes by reducing the size and power of the muzzle blast? Let’s say, 3”-to-6” back from the muzzle we bore a series of holes, following the grooves of the barrel, with the holes equalling perhaps 2 or 3 times the area of the calibre to ensure most of the pressure is bled down (for a .30 cal barrel, .30 cal equals about 0.071 square inches, so it would require 46 to 70, 1/16” holes). We would, of course have to carefully balance the holes to minimize any unequal thrust applied to one side of the barrel, we’d also have to minimize any stiffness loss to the muzzle, maybe by increasing the diametre of the barrel along the ventilated area to make-up for the loss of material.
Thus the bullet gets to coast through the final 3” of barrel and exit from the muzzle mostly undisturbed.
Would this work?
I doubt this is an original idea.
I’m familiar with “Magnaporting”; but I don’t believe the port area was sufficient in the examples I’ve seen and because the main purpose of it seemed to be recoil and muzzle-rise control, uneven thrust distribution would have not been seen as a drawback.
Boattailed bullets can take a couple hundred metres to completely stabilize once they leave the muzzle.
I’ve read that one of the major factors in this instability is that the blast of propellant gasses flow around the bullet, remaining laminar for a relatively long period.
Short range benchrest shooters use flatbased bullets because they stabilize much faster and the bullets do this because the gas deflecting off the flat base interrupts the powder gas flow along the bullet.
Now if this stuff is true, wouldn’t barrel porting work to decrease groups sizes by reducing the size and power of the muzzle blast? Let’s say, 3”-to-6” back from the muzzle we bore a series of holes, following the grooves of the barrel, with the holes equalling perhaps 2 or 3 times the area of the calibre to ensure most of the pressure is bled down (for a .30 cal barrel, .30 cal equals about 0.071 square inches, so it would require 46 to 70, 1/16” holes). We would, of course have to carefully balance the holes to minimize any unequal thrust applied to one side of the barrel, we’d also have to minimize any stiffness loss to the muzzle, maybe by increasing the diametre of the barrel along the ventilated area to make-up for the loss of material.
Thus the bullet gets to coast through the final 3” of barrel and exit from the muzzle mostly undisturbed.
Would this work?
I doubt this is an original idea.
I’m familiar with “Magnaporting”; but I don’t believe the port area was sufficient in the examples I’ve seen and because the main purpose of it seemed to be recoil and muzzle-rise control, uneven thrust distribution would have not been seen as a drawback.
