Started trying get the 190s to shoot subsonic in 308 Ruger American. The 322 and 4885 both shot well at 1050 but both seemed loud to me. Tried the Titegroup and settled on 8.1 at 1040 as a good quiet load that shoots pretty decent.
308 win 190 subx aubsonic
- Thread starter Eric Leonard
- Start date
It’s my sons rifle I’ll have to ask him, he just left with it but it’s just a factory Ruger American so assume it’s a 10 but I’ll make sure and let you know
He said it was a Predator Gen II 22” bbl 1-10 twist
I also load the 190 Sub-X over 8.1gr Titegroup. The suppressed 20" 1:10 twist Rem700 sends it at ~1080fps and they are reliable 1 MOA loads. I pressed out to 300yds just for fun and it ignored the wind.
I also have 175gr subsonic plinker loads over 7.5gr Titegroup that go ~1080fps, too. They also stay 1 MOA at 100yds and are stable out to 200yds.
I also have 175gr subsonic plinker loads over 7.5gr Titegroup that go ~1080fps, too. They also stay 1 MOA at 100yds and are stable out to 200yds.
Found the sierra matchkings 175 180 to be good projectiles in the 308 sub area. Really hard to get consistent results with the big case volume and low pressures. Would like to play with a 338 arc or 338 br and see if combustion cleans up.
1 my sons bought some kind short barreled AR pistol in 338 ARC and it shoots the factory ammo very well. It surprised me in fact how well it shot.
Dellet reports the 175gr SMK to be a great subsonic bullet in 300BO… very accurate for target shooting out to distance (300 yards). Just keep in mind that the SMK is not a bullet designed for expansion or fragmentation, especially at subsonic velocity.
Case Capacity of 338ARC ~34gr, 30BR ~41gr, 8.6BO ~46gr.
I haven’t seen any discussion on using the BR case… it has all been either 338 Razorback, 338ARC or 8.6BO. Have you tested the fit of +300gr projectile into BR case to determine whether the heavy projectile and short case still reliably feed from a magazine. Does it still fit in magazine with BR kit? If it doesn’t then how does it function in standard AICS magazine? I know that with the longer 8.6BO case reliably feeds/extracts in bolt rifles and gas guns.
The 1:3 twist is nifty meat blender with 8.6BO, but a 1:5 twist is still fast enough to get great cavitation while still getting the solid copper projectiles to fully expand. These faster twist are huge multiplier at subsonic velocities. The solid copper projectiles, which tend to be most accurate… and lethal. Lead core projectiles, such as SubX, do better in slower twists (1:6 - 1:8).
There are some great subsonic gel block videos testing twist rates and bullets on YouTube.
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Ok - my curiosity got the better of me… why no major development of BR case for subsonic??? It turns out there was a little known cartridge called the .338 Whisper that was based on the 7mmBR case. It was created by JD Jones (SKS Industries) in the early 1990’s. He created two versions with the 338 Whisper (Type 1) based on BR case and the 338 Whisper (Type 2) based on 221 Fireball case. For those who are curious these are the interesting details.
Wikipedia - 338 Whisper
338 Whisper (Type 1) - Cartridge Diagram
PTG Chamber Reamer - 338 Whisper
Wikipedia - 338 Whisper
338 Whisper (Type 1) - Cartridge Diagram
PTG Chamber Reamer - 338 Whisper
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