All data in this caliber is subsonic but is not normally tagged with the name subsonic. Bullet: 220gr Sierra Pro Hunter RN (MFG Part #2180) Powder: Trail Boss Subsonic Trail Boss Loads . IMO, Trail Boss is the best subsonic-load powder on the planet, if you don't really care about cycling. Here's my quandary. The lightest I would recommend for a sub is a 190 grain. The advantages of such loads, the posters type, are low noise and an absence of recoil, and I’m all for that. Thanks in advance for any replys Re: Subsonic load for 308 with Trail Boss Trail Boss is not in the database of the Quickload software I have but I was able to get some data with a powder I know to be similar in burn rate. The 300 AAC Blackout is a similar concept to previous wildcats, such as the 30-221 and 300 Fireball, as well as the proprietary 300 Whisper®, except that 300 BLK was the first to be a SAAMI approved cartridge and any company is free to make firearms or ammunition. Some of us know that this caliber began life as the 300 Whisper. Then fill the case to that mark with Trail Boss, pour into the scale pan and weigh. *Shaded column displays subsonic load data. The advantages of such loads, the posters type, are low noise and an absence of recoil, and I’m all for that. Date: Jul 31 2013 These loads and others were shot with Trail Boss powder in an attempt to develop subsonic velocities (left to right): .30-06, .308 Winchester,.30-30 Winchester, .243 Winchester, .223 Remington. Take 70% of this powder charge weight (multiply the maximum load from step 1 by .7), and that is your starting load. I have Trail Boss but my go to powder for subs in my 300 Blackout is Little Gun. According to my data: 135 SMK's 7gr Trail Boss 1000 … Author: John Haviland / Wolfe Publishing Co.

3 6 8 1. In 9mm, most loading data are supersonic. Full length size. Trail Boss 5.6 Energy/ft.lbs 269 882 977 1077 1182 1292 1407 INDICATES MAXIMUM LOAD - USE CAUTION LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED. I use 7.1 to 7.2 GN LG. I spent weeks trying to get an idea of where to start for subsonic .308. Trail Boss 5.6 Energy/ft.lbs 269 882 977 1077 1182 1292 1407 INDICATES MAXIMUM LOAD - USE CAUTION LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED. 3 6 8 1. Pressures will be below the maximum allowed for this cartridge and perfectly safe to use!

My initial objective here was to develop subsonic loads.

I want to be able to load the 150 and 160 grain bullets out to the proper place in the case mouth, and that just cannot be done with the AR-15 mag length restriction. Unlike the reduced power H4895 loads, which in both the 6.5 Creedmoor and 308 Winchester had similar points of impact (POI) to their full power counterparts, the Trail Boss loads all had a POI at 100 yards that was lower than the full power equivalent.