Porting a magnum handgun
I have a bit of a nimrod question, but if I don't ask, I don't learn.
I was just watching the TV show Handgun, in which they featured 41 and 44 magnum revolvers. Several were ported for recoil....my question is, does porting reduce the velocity of the round? and by how much? If it is substantial, why not just shoot a less powerful handgun such as a 357, if the muzzle jump is such a problem? Thanks!
I was just watching the TV show Handgun, in which they featured 41 and 44 magnum revolvers. Several were ported for recoil....my question is, does porting reduce the velocity of the round? and by how much? If it is substantial, why not just shoot a less powerful handgun such as a 357, if the muzzle jump is such a problem? Thanks!
0
-
I've had .44's in 5 1/2, 6 1/2, 7 1/2 and 8 3/8 barrel lengths. My favorite is a flat-top blackhawk with a 6 1/2" magna-ported barrel.
While I don't have before/after velocity figures, as near as I can tell there's no appreciable velocity loss. That said, I wouldn't go to the expense of porting any of my .44's. The 6 1/2 I have only because it came that way. Doesn't bother me, and it took a beautiful pistol out of the "collector" realm, and down in the lower stratosphere where I could afford it.0 -
Reduce the velocity, yes. How much? Not quite as much as having a 1" shorter barrel.
Velocity increase in not linear, IOW the bullet will accelerate much more in the first inch than it will in the last inch0 -
I have a 6" barrel ported .44 mag that I take with me hiking/backpacking and hunting (for back up) in the big bear (blacks and grizzlies) country of Montana. I personally would not rather run into them. [:p] My pistol shoots comparable to .357's recoil and I shoot it comfortably and effectively up to 10-15 yards. I purchased the gun and practice at that range for it's purpose ... bear encounters.
The velocity loss with the porting is very negligible but the muzzle jump/recoil reduction attained is tremendous. I was faced with the same challenged before my purchase and was leaning more toward the .357. But with the porting and the inherent advantage of the .44 mag, my choice became more apparent.
357 Mag 158 gr XTPr
Test Barrel (8 V") Velocity (fps) / Energy (ft-lbs)
Muzzle 50 100
1250/548 1150/464 1073/404
44 Mag 240 gr XTPr
Test Barrel (7.5 V") Velocity (fps) / Energy (ft-lbs)
Muzzle 50 100
1350/971 1231/807 1134/685
The key is get the caliber you can effectively shoot - shot placement is key - practice, practice, practice - no excuses! [}:)][:p][^]
Cheers!
Ed
ADDED:
Check out this video, I have the same model except blued ...
http://www.youtube.com/watch?v=itMT7bF7eV8&feature=related
(C&P)
Mag-na-port has been tested many times since its initial introduction. H.P. White Laboratories performed tests on rifles equipped with and without Mag-na-port to determine the effect on free recoil and velocity. Findings in the laboratory-conducted test had a 20.8% reduction in free recoil for the rifle equipped with Mag-na-port. These same tests noted velocity averages less than four-tenths of 1 percent with the Mag-na-ported rifle, considered statistically insignificant.
In tests at Cornell University using a series of compression sensors rigged to a modified Ransom Rest mounted on a spring-loaded sliding track connected to an oscilloscope, a before and after analysis of the effect of Mag-na-porting on a series of different calibre revolvers was conducted. These tests were on revolvers ranging from .38 Special to .44 Magnum, in barrel lengths from 2 to 8-3/8 inches and frame sizes from small to heavy. Recoil reduction ran from a low of 11% on the .38 to a high of 47% on the 44 magnum. The conclusions drawn from the tests confirmed that Mag-na-port does not decrease bullet velocity or increase muzzle blast. These same tests also confirmed that Mag-na-port does reduce the intensity of apparent recoil.
(http://www.statusguns.com/agents_ProPort.htm)0 -
I have never seen a brake reduce velocity in anything I've ever put a brake on... 0 -
quote:Originally posted by mrbruce
I have never seen a brake reduce velocity in anything I've ever put a brake on...
Brake's are beyond the muzzle, ports are before the muzzle0 -
quote:Originally posted by ltcdoty
I have a bit of a nimrod question, but if I don't ask, I don't learn.
I was just watching the TV show Handgun, in which they featured 41 and 44 magnum revolvers. Several were ported for recoil....my question is, does porting reduce the velocity of the round? and by how much? If it is substantial, why not just shoot a less powerful handgun such as a 357, if the muzzle jump is such a problem? Thanks!
In *theory* porting reduces the velocity because you're giving up some integrity from the full barrel length, but in practice, this is only by a negligible amount, probably less than 2%.
I suspect that ordinary shot-to-shot variation in velocity will exceed the absolute reduction in velocity from porting the typical revolver, and unless you were chronographing a good number of rounds before-and-after to compare median velocities, you'd probably never notice the difference.
As mentioned, you'll lose more velocity by cutting off an inch of barrel length than you will from any normal porting job.
The reason you don't go to a lesser powered round is because a ported .44 magnum is still a lot more powerful than a non-ported (or ported) .357.
The way porting works is by directing some of the muzzle exhaust gasses directly upward (and possibly a little backward towards the shooter). The gasses going up tend to push downwards on the end of the barrel, partially counteracting muzzle flip.
There are several reasons why this isn't done to ALL revolvers:
-Venting gasses upwards also vents muzzle FLASH upwards right into the sight picture. Not good for night vision, and flames shooting upwards from the muzzle can cause their own problems.
-Porting adds cost to the gun.
-Ported guns are perceived as louder by the shooter.
-The ports themselves can accumulate dirt/carbon, requiring more maintenance (cleaning).
Edit: Note that there is a difference between PORTING (where you drill holes in an existing barrel) and BRAKING (where you add a muzzle device AFTER the barrel).
Since the bullet is effectively out of the gun before it takes effect, BRAKING should not affect muzzle velocity at all.
PORTING, on the other hand, does bleed off some gas from the barrel BEFORE the bullet leaves the barrel. So there will be SOME reduction in velocity, though as above, in practice the amount of velocity reduction is so small that you're never going to notice it.
Also note, that there is a difference between porting a RIFLE and porting a magnum PISTOL. In a rifle, you can expect the bullet to have achieved near maximum velocity by the time it hits the end of the barrel (though this will depend on the exact load and gun). Particularly with a magnum pistol, the bullet will still be accelerating when it hits the muzzle, meaning bleeding off a little gas from the pistol barrel will likely affect velocity more than with the rifle.0 -
"TV show Handgun"? That's something I'd love to see!
Any info about where I can look for it?0 -
I have a .44 Redhawk I use for hunting that I had ported. Having fired it both ways, my conclusion is that porting reduces recoil but increases felt muzzle blast. Under no circumstances would I port a self-defense handgun; the blast will blind you in the dark. 0
Please sign in to leave a comment.
Comments
9 comments