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Posted: 9/2/2006 5:10:39 AM EDT
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When using 9mm ammo with a suppressor... does the higher the grain number (eg 147 grain) mean the bullet will, in most cases, be heavier and therefore travle slower (not necessarily subsonic). So if you have a 147 grain round and a 115 grain round the 147 grain round will be quieter in your suppressor? |
| Depending on atmospheric conditions the speed of sound is around 1100fps. Any object (bullet) travelling slower than that will not break the sound barrier and create a sonic 'crack'. The muzzle 'bang' is what you hear when you are close to the gun, the sonic 'crack' is what people hundreds of yards away hear. 115gr 9x19 is usually supersonic from a 4" barrel, 147gr 9x19 is usually subsonic from a 4" barrel and 124gr 9x19 could go either way depending on the load. When buying ammo go to the manufacturers' website and look at the ammo specifications, it will list the velocity from a pistol. The ammo I use is Federal American eagle AE9FP and EA9N2 147gr subsonic. If you down-load 115gr ammo to subsonic velocities there probably won't be enough recoil force to cycle most autos unless you tune the springs to work and then you couldn't fire full-power loads without damaging the gun. |
7000 grains to the pound. So yes, higher numbers are heavier, and yes, heavier bullets are usually slower, but not always. |
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