Nightcrawler
Member
Been thinking about the use of suppressed weapons.
They have the distinct advantage of making a weapon quieter; they don't "silence" it, by any means, and that whole bit about the MP5SD's bolt reciprocation being more audible than the round firing is probably just a silly urban legend.
However, a suppressed .223 or .308 round will still have an audible sonic crack as the bullet passes by, as the bullets are moving in excess of the speed of sound. Granted, a good .308 suppressor can give the rifle the report of a .22, making it much harder to locate the firer, and that's the idea.
But for idealized suppressed use, you want to utilized subsonic ammunition. It makes an audible difference.
Some weapons are more suited for this than others.
Rifle rounds, typically, are not so well suited. The reason is this. There are two factors that contribute to how much energy a fired round has: bullet mass and bullet velocity. Subtract one and you need to increase the other to keep the energy the same.
Most rifle rounds are bigger on velocity than they are in bullet mass (especially small bore rounds like .223 and 5.45mm).
So, given that the speed of sound at sea level is roughly 1100 feet per second, let us consider 1100FPS at the muzzle the "speed limit" for proper suppressor ammo.
Suddenly, 5.56mm isn't looking so good. 55 or 62 grains at 1100 fps? Pretty sad, performance wise. What's the heaviest 5.56mm bullet available?
.308 fairs better, but not by much. The heaviest factory .308 loads seem to be 180 grains. (The only factory box of .308 subsonic I've seen had 180 grain bullets.) 180 grains at 1100 fps is barely low-level .357 Magnum territory. Now, they make heavier .30 caliber bullets than that; specifically, 220 grain bullets that some .30-06 loads use. I don't know if you could make one of these work in a .308 case, though.
Pistol rounds typically give up less than rifle rounds in this department. For 9mm, you typically have 147 grain bullets at 950-1000 fps, which is a regular standard-pressure load. Other non +P loads are subsonic at the muzzle, too. But if you're maximizing suppressed power, you want the heaviest bullets possible, and the heaviest usable for 9mm is 147 grains, I believe.
.45ACP gives up practically nothing as most .45 loads (including +P) are subsonic at the muzzle anyways. And if your speed limit is 1100 feet per second, a 230 grain bullet beats a 180 grain one.
10mm...don't know how well this would work. There are 220 grain 10mm bullets, though they're not available in any factory load. 220 grains at 1100 fps is pretty respectable for a pistol round, and would offer better penetration than a .45ACP load. (Were any subsonic 10mm loads developed for the suppressed MP5/10mm?)
.357 Sig. Probably better than 9mm in this regard, as it'd have an easier time pushing the heavier bullets to the 1100 fps limit.
.40S&W: Most factory 180 grain loads are subsonic anyways, so unless you want the lighter bullets you're not losing anything.
9x18mm: I believe all 9mm Mak loads are subsonic anyways.
Then you get some oddballs, like .300 Whisper. .300 whisper is a GOOD idea. You can get the .30 caliber bullet to 1100 FPS without all of that wasted case capacity you'd get in a .308. .300 Whisper (in Cor-Bon's load) uses a 220 grain .30-06 bullet and pushes it to 1040 FPS; it equals the performance of suppressed .308 in a smaller, lighter package. (In theory, with the extra case capacity, .308 could push a heavier bullet to the same speed, but I think 220 grains is the heaviest .30 caliber bullet available right now.)
What I think would be REALLY interesting for suppressed use would be some of the big bore magnum loads. Again, if your maximum velocity is 1100 fps, you may as well have the heaviest bullet possible. There are 300+ grain bullets available for the .44 Magnum. Obviously, suppressing a revolver has its own set of problems, but you could use the .44 Magnum round in a semiauto "thumper" carbine with an integral suppressor. Better suited to such a carbine would be the nearly-extinct .45 Win Mag round, with its 320 grain bullets. .50AE could work too.
Just some late night musings. Any thoughts?
They have the distinct advantage of making a weapon quieter; they don't "silence" it, by any means, and that whole bit about the MP5SD's bolt reciprocation being more audible than the round firing is probably just a silly urban legend.
However, a suppressed .223 or .308 round will still have an audible sonic crack as the bullet passes by, as the bullets are moving in excess of the speed of sound. Granted, a good .308 suppressor can give the rifle the report of a .22, making it much harder to locate the firer, and that's the idea.
But for idealized suppressed use, you want to utilized subsonic ammunition. It makes an audible difference.
Some weapons are more suited for this than others.
Rifle rounds, typically, are not so well suited. The reason is this. There are two factors that contribute to how much energy a fired round has: bullet mass and bullet velocity. Subtract one and you need to increase the other to keep the energy the same.
Most rifle rounds are bigger on velocity than they are in bullet mass (especially small bore rounds like .223 and 5.45mm).
So, given that the speed of sound at sea level is roughly 1100 feet per second, let us consider 1100FPS at the muzzle the "speed limit" for proper suppressor ammo.
Suddenly, 5.56mm isn't looking so good. 55 or 62 grains at 1100 fps? Pretty sad, performance wise. What's the heaviest 5.56mm bullet available?
.308 fairs better, but not by much. The heaviest factory .308 loads seem to be 180 grains. (The only factory box of .308 subsonic I've seen had 180 grain bullets.) 180 grains at 1100 fps is barely low-level .357 Magnum territory. Now, they make heavier .30 caliber bullets than that; specifically, 220 grain bullets that some .30-06 loads use. I don't know if you could make one of these work in a .308 case, though.
Pistol rounds typically give up less than rifle rounds in this department. For 9mm, you typically have 147 grain bullets at 950-1000 fps, which is a regular standard-pressure load. Other non +P loads are subsonic at the muzzle, too. But if you're maximizing suppressed power, you want the heaviest bullets possible, and the heaviest usable for 9mm is 147 grains, I believe.
.45ACP gives up practically nothing as most .45 loads (including +P) are subsonic at the muzzle anyways. And if your speed limit is 1100 feet per second, a 230 grain bullet beats a 180 grain one.
10mm...don't know how well this would work. There are 220 grain 10mm bullets, though they're not available in any factory load. 220 grains at 1100 fps is pretty respectable for a pistol round, and would offer better penetration than a .45ACP load. (Were any subsonic 10mm loads developed for the suppressed MP5/10mm?)
.357 Sig. Probably better than 9mm in this regard, as it'd have an easier time pushing the heavier bullets to the 1100 fps limit.
.40S&W: Most factory 180 grain loads are subsonic anyways, so unless you want the lighter bullets you're not losing anything.
9x18mm: I believe all 9mm Mak loads are subsonic anyways.
Then you get some oddballs, like .300 Whisper. .300 whisper is a GOOD idea. You can get the .30 caliber bullet to 1100 FPS without all of that wasted case capacity you'd get in a .308. .300 Whisper (in Cor-Bon's load) uses a 220 grain .30-06 bullet and pushes it to 1040 FPS; it equals the performance of suppressed .308 in a smaller, lighter package. (In theory, with the extra case capacity, .308 could push a heavier bullet to the same speed, but I think 220 grains is the heaviest .30 caliber bullet available right now.)
What I think would be REALLY interesting for suppressed use would be some of the big bore magnum loads. Again, if your maximum velocity is 1100 fps, you may as well have the heaviest bullet possible. There are 300+ grain bullets available for the .44 Magnum. Obviously, suppressing a revolver has its own set of problems, but you could use the .44 Magnum round in a semiauto "thumper" carbine with an integral suppressor. Better suited to such a carbine would be the nearly-extinct .45 Win Mag round, with its 320 grain bullets. .50AE could work too.
Just some late night musings. Any thoughts?
