Having a high BC bullet at subsonic speeds does not benefit the shooter at all. 300 BLK subsonic loads the other day for a 1:8 8 barreled AR. BC (ballistic coefficient) is for supersonic flight, and does not matter at subsonic speeds. This allows the 100 grain SP flat base to be more stable and have the potential to be more accurate at subsonic speeds than a BTHP design. At 1050 fps, most 270 bullets apparently wont stabilize.

The 100 grain SP flat base is a much shorter bullet than a similar weight BTHP bullet, like a Berger or similar BTHP bullet. Ive read up a little about people doing subsonic 270 and the biggest problem seems to be stability. In a given twist rate (like a 1:8″ or 1:10″ barrel twist) and slow subsonic speeds, a shorter, flat base bullet is more stable than a longer BTHP match bullet is. Bullet length is a major factor in how stable it is out of the muzzle. These capture and spin bullets at very high rotational velocities to produce artificial stability to overcome the natural stability, which is actually their. Why use a 100 grain SP (soft point) flat base bullet, instead of a BTHP or match bullet? When shooting at subsonic speeds, bullet stability becomes a huge factor for the bullet to properly stabilize and for it to shoot well. Note- If you are sighted in with standard full power 25-06 ammo, this subsonic round will impact about 10″-12″ low from a 100 yard zero.

If you do not have a 1:10″ twist, please contact us about this ammo for bullet stability. 100 grain SP 1040 fps in 24″ suppressed barrel (about 1020 fps in 22″ barrel). New Hornady 25-06 brass, Sierra 100 grain SP Pro Hunter bullet, Federal 210M (match) primer, all loaded at subsonic velocity! A 1:10″ twist barrel is REQUIRED for this bullet to stabilize. You may know that the 300 Blackout can get close to Hollywood quiet, especially in a bolt action rifle with subsonic ammo.

Subsonic bullet stability