8.6 BLK Thread

[STFU]

Bullet RPM = MV X 720/Twist Rate (in inches)

For a subsonic - 1050 x 720/3 = 252,000 rpm (300gn Matchking)
For a supersonic - 1970 x 720/3 = 472,800 rpm (210gn Barnes TSX)

For comparison -
308 supersonic - 2800 x 720/12 = 168,000 rpm

For further comparison:

(300BLK) MUZZLE VELOCITY​	TWIST RATE​	BULLET RPM​
1070​	8​	96,300
1070​	7​	110,057
2077​	8​	186,930
2077​	7​	213,634

1070 fps is my home brew 220gr
2077 fps is S&B 147gr

That 1:3 twist is amazing...

 

[Jowl1]

8in 8.6 sig cross

 

[Aszerigan]

Just got notice. - Starline is releasing their first batches of 8.6 to dealers now. It is now an officially mainstream cartridge.