Subsonic

SDW308 · June 4, 2009, 10:16 AM

Does anyone have a good subsonic load for a .308? If so do I need a case filler and what kind of case filler?

**Unclenick** · June 4, 2009, 06:28 PM

If you want to play with case fillers, avoid the high bulk ones, like Cream of Wheat or corn meal. They have been known to be involved in chamber ringing. Polyester pillow stuffing seems to work OK as it is mostly air and melts down to a thin disc.

That said, if you are going to hold the .308 down to subsonic velocities, you will be shooting Bullseye or some other very fast pistol powder that isn't very sensitive to position in the case, so you probably won't need the filler. There is a series of three articles on a Finnish web site on how to develop subsonic .308 loads. It is worth a read, though the English version is not entirely fluent.

freakshow10mm · June 4, 2009, 08:16 PM

Work up loads with TrailBoss.

**Unclenick** · June 5, 2009, 06:02 AM

Trail Boss is a good idea, but it is strictly for cast bullets in a rifle. The maker claims odd pressure spikes are observed using it for jacketed bullets. I have no clue why that should be so, but like my guns too much to try to test it for myself.

June 4, 2009, 10:16 AM	#1
SDW308 Junior Member Join Date: June 3, 2009 Posts: 6	Subsonic Does anyone have a good subsonic load for a .308? If so do I need a case filler and what kind of case filler?

June 4, 2009, 06:28 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	If you want to play with case fillers, avoid the high bulk ones, like Cream of Wheat or corn meal. They have been known to be involved in chamber ringing. Polyester pillow stuffing seems to work OK as it is mostly air and melts down to a thin disc. That said, if you are going to hold the .308 down to subsonic velocities, you will be shooting Bullseye or some other very fast pistol powder that isn't very sensitive to position in the case, so you probably won't need the filler. There is a series of three articles on a Finnish web site on how to develop subsonic .308 loads. It is worth a read, though the English version is not entirely fluent. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

June 5, 2009, 06:02 AM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Trail Boss is a good idea, but it is strictly for cast bullets in a rifle. The maker claims odd pressure spikes are observed using it for jacketed bullets. I have no clue why that should be so, but like my guns too much to try to test it for myself. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

June 4, 2009, 08:16 PM	#3
freakshow10mm Junior member Join Date: January 23, 2008 Location: MI Posts: 1,398	Work up loads with TrailBoss.