subsonic .308

[Guest 556or762]

Well since I have gotten my YHM 7.62 suppressor picked up I have tried loading some subsonic .308 using berger 175gn bullets. I got some info from Hogdon on a few loads using trailboss and other pistol powders Trailboss having the highest sectional density to try to fill the case best I could. I started by drilling out the flash hole to 1/8" on my brass then loaded remington MAGNUM primers and 8.0 to 11gn of trailboss in .5gn increments with std 2.8oal. I have to say it is quiet out of a 20" barrel, I have not gotten it over a chrono yet but the 11gn seems to be right on the verge of supersonic so temp and humidity might take it over the edge but 10gn seems to be a good compromise on velocity and sound once I get some velocities I will fine tune it to within about .4gn of supersonic to get the most energy. Ill update after I get these rounds on a chrono if anyone has any insight let me know, my other 308 has a 26"barrel so I would like to make sure I have 1 subsonic round that stays subsonic in it and I know the 20"will be good, I also have some outlaw 220gn bullets to try once I get a baseline with the 175's.

[Guest fdx28]

With an 18" barrel, 11.25 twist and loading 180 Hornady's, 10.7gr of Trailboss with Winchester Mag LR primers gave me right at 980-1000 fps and the most accuracy. I used FGMM cases as I wasn't worried about the soft brass with low pressures. I worked 10.0 to 11.0 with .1 increments. I used the Possum Hollow flash hole tool to open it up a little bit.