Subsonic 308 with no Trail Boss

[outrider58]

Since pressure spikes are to be considered with using titegroup, I would only attempt this on plated/cast bullets sized to +.001 overbore. GRT says a range of 3-4 grains of titegroup should achieve subsonic values for bullet ranges from 160-200 grains.

I run 4.5 grains along a 165 grain plated 9mm bullet sized to .356 on the 350L, achieving transonic velocities (~850 fps).

I don't go above 4.0 on any of my super 9mm. I know there is a very narrow range with 9mm. It it very easy to slip below reliably with it. I love how it shoots though. I've been reloading 9mm for years with it. It's my favorite powder for 9mm.

 

[motox79]

I’ll be honest. I was worried most about case fill. When I saw Hodgen actuall list a load data for the 190 sub x I was excited (though I’m not gonna lie….. when I took my first shot I was flinching) I’m hoping with the 255gr sub x (1.575” long, and a flat base) it will shot fairly consistent since a lot more of the case is filled. I’m still keeping an eye out for trail boss (in case anyone has a source) but I’m excited to try to work up a load.

 

[motox79]

Take a look!

 

[lazarus]

I’ll be honest. I was worried most about case fill. When I saw Hodgen actuall list a load data for the 190 sub x I was excited (though I’m not gonna lie….. when I took my first shot I was flinching) I’m hoping with the 255gr sub x (1.575” long, and a flat base) it will shot fairly consistent since a lot more of the case is filled. I’m still keeping an eye out for trail boss (in case anyone has a source) but I’m excited to try to work up a load.

Unless you've double loaded it, don't flinch.

You aren't anywhere remotely close to maximum pressure running pistol powders at subsonic velocities in rifle cases. If I've got the time later I'll punch some data in to GRT, but if I am remembering off the top of my head, when I was looking at a 156gr subsonic load for grendel using Bullseye, I think it was around 5gr of powder to hit ~1000fps and I think GRT was saying max pressure was in the mid 20k range. To exceed maximum safe pressures, you'd need to more than double charge the case. I think even with 10gr, GRT was claiming something like 1700-1800fps and like 40-45k psi peak.

 

[Blacksmith101]

Another thing worth looking into, search Ed Harris's "The load - 13 grains of Red dot" for low power/subsonic 30 caliber or larger rounds.

He cooked up a lot more than Ed's Red actually...

Link to "The load - 13 grains of Red dot":

"The Load" is 13 Grains of Red Dot"