Is there a difference? From what I gather, most of the 9mm 147gr bullets travel at subsonic speeds anyways. Are "subsonic" rounds loaded to an even slower velocity?
Most of the Max loads for 147gr 9mmx19 is still slower than 1125fps. So technically, its all subsonic.
Now I will say, *my* subsonic loads are using minimum and sometimes a touch below minimum loads. Basically just enough to cycle the gun with a supressor on it (wont cycle without one).
Now I will say, *my* subsonic loads are using minimum and sometimes a touch below minimum loads. Basically just enough to cycle the gun with a supressor on it (wont cycle without one).
Ok, thanks Whitey. That's what I figured, but people advertise 147gr ammo as subsonic like there's something special with that....
OKC ~1200f above sea level. (All FPS I give,... multiply by .9873)
Humidity barely plays a role in the speed of sound, as humidity increases so should the speed of sound, but the increase is slight.
The only noteable change occurs with temp...
So lets say:
0*F = 1050fps
60*F = 1117fps (OKC annual average)
103*F = 1162fps
Most fiocchi data I see has it rated at 1000-1050. Unless it was some +P I have never heard of...
Now if you chrono'd it and it came out faster... then I guess I wont be buying fiocchi as they obviously load hotter than their listed data.
Humidity barely plays a role in the speed of sound, as humidity increases so should the speed of sound, but the increase is slight.
The only noteable change occurs with temp...
So lets say:
0*F = 1050fps
60*F = 1117fps (OKC annual average)
103*F = 1162fps
Most fiocchi data I see has it rated at 1000-1050. Unless it was some +P I have never heard of...
Now if you chrono'd it and it came out faster... then I guess I wont be buying fiocchi as they obviously load hotter than their listed data.
Looking in speer's manual, what I have at hand for the moment, depending on powder 820-1000 fps.
Interesting not they also say 147gr bullets NOT recommended for barrrels longer than 10 in. Funny I have not seen this not in other manuals. I use it in a 16 in barrel seems to be ok??
Interesting not they also say 147gr bullets NOT recommended for barrrels longer than 10 in. Funny I have not seen this not in other manuals. I use it in a 16 in barrel seems to be ok??
is subsonic better for hollow points? does it help with the efficacy of taking down a bad guy?
You might be able to drive a 147 above the speed of sound, but there's no reason to. Most of the 147 JHP's are designed to expand efficiently at subsonic velocities.
FWIW, it's best to keep suppressor loads around 950. Regardless of what the speed of sound is based on atmospheric conditions, the decibel levels climb noticeably above 950.
FWIW, it's best to keep suppressor loads around 950. Regardless of what the speed of sound is based on atmospheric conditions, the decibel levels climb noticeably above 950.
only time I specifically use subsonic 9mm is if i'm shooting suppressed.
Assuming PF for +p 9mm is around 150,000 (someone correct me if I am wrong) then at 147 grain, that would imply subsonic.
If someone is loading 147 grains at supersonic they are probably going +P+, which may be dangerous.
So i would guess most 147 grain ammo is subsonic already.
Labeling it as such implies its usability with a suppressor (which is why it was originally developed perhaps)?
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