Quote:
Originally Posted by gtiso
I have been trying to work up a subsonic load using lil gun and 220gr smk
I am using a 16" barrel ar15 gas port in the carbine position in 85 deg weather
lake city brass winchester small rifle primer
8.5 gr 1306fps
7gr 1098fps
6.5gr 1067fps
6gr 1035fps
just curious how my results compare to anyone else's
6 gr of lil gun is not very much volume in the case
I am thinking about another powder
I have some 322 has anyone tried using this for a subsonic load
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The speed of sound changes mostly with temp. and a bit with humidity. The pressure/elevation has very little impact on the speed of sound.
For the conditions that you list above (85 deg F) the speed of sound is about 1144 fps. So your 7gr load of LilGun is your best subsonic load. Your 7 gr load will be subsonic at temps down to about 48-50 deg F.
A good velocity to shoot for (pun intended) is about 1080 which is subsonic down to a temperature of about 30 deg F.
With a deep seated long 220gr SMK, 7gr of LilGun should pretty much fill the case. So it looks to me that you already have a good load if it hold a nice tight group.
I hope this helps.
320pf