Subsonic data source

[maggot]

I'm looking for a source of subsonic reloading data for rifle calibers.Like .223 .243 .308 7.62x39,ect

[ricciardelli]

All you have to do is launch your bullet at less than 800 FPS, and it is a "sub-sonic" load.

But why?

[PaulS]

Steve,
the speed of sound under "normal" atmospheric and "standard" pressures is 1100 fps.

Maggot,
look at "reduced velocity loadings" in the manuals that you have or, if your manuals don't show reduced loadings go to the bullet manufacturer's website and ask them what they would recommend for a 1000 fps loading.

PaulS

[Leftoverdj]

Use cast bullets for this work. There are reports of jacketed getting stuck. Cast is much less likely to get stuck and much easier to get out.

The usual reasons for wanting subsonic ammo are for firing in a suppressed gun or for an accurate small game load. 1050 fps almost always gives good accuracy and a trajectory close enough to .22 lr to be intutitive for most of us at small game ranges.

If noise suppression is the issue, use the fastest powder that will give you the velocity you need. More powder = more gas = more noise. This holds for both suppressed and unsuppressed guns.

[ricciardelli]

Steve,
the speed of sound under "normal" atmospheric and "standard" pressures is 1100 fps.PaulS

Yup, I know that...but I always use 800 because that is what the factory .45ACP (non+P) does.