.308 subsonic

[1911bmw]

I have been researching subsonic loads for my .308.  Heavy bullets and trailboss seem to be the way to go.  Everything I've read says about 10 grains of powder should give me velocities around 1000fps.  I started with 9 grains.  The hammer fall was the only sound I could hear and the bullet landed 5 feet in front of me.  10 grains put the bullet about 40 feet.  What did I do wrong?

220 gr hornady innerlock
10 gr imr trailboss
standard federal primers
new federal cases
20 degrees outside
22 inch barrel (cleaned)

[Hit or Miss]

I'm suspecting that the jacketed bullet is part of the problem.  It takes a little more powder to push them to speed as they don't seal the barrel as well as lead.  Check out this link too, http://www.imrpowder.com/PDF/Trail-Boss-data.pdf good information.

[jhalcott]

 Definetly go with a heavy for caliber CAST bullet. Check accuracy with and with out the gas check if the design calls for one. Seating depth WILL be a factor also. 20 to 22" barrels seem to work better than longer ones in MY limited experience.Velocity MAY have to be closer to 1100 fps IF deer are the target. If you are looking for a soft recoiling load for the kids to start with, a .22 rf may be a better choice. Remember that the .308 has a short neck. This can allow those long bullets to become "bent"in the case. So look for a bore rider design that will line up truer in the bore.

[1911bmw]

Thank you.  The IMR info was interesting.  Deer are the target.  I live out of city limits but still have close neighbors so I was hoping for something quiet.  I tried drilling the flash hole to 1/8 and magnum primers with 10 grains today and the bullet made it to my 30 yard target fast enough to knock snow off of it but I could still see the bullet in flight.  Very quiet though.  I guess I will get some cast bullets and see if that does the trick.  I read that the natural lube in the lead bullets  helps.

[shot1]

If you are going to go after deer with those low velocity loads you better shoot them in the head and make sure you hit the brain or they will be running all over those close neighbors yards leaking blood all over the place.