Re: What is the ultimate subsonic round?
As any sub can only be driven so fast, how about bigger bullets?
We've been stuffing Lehigh pills in 458 Socom cases. Examples in my pic above. This project is still in the R&D stages but making good progress. A dedicated sub-only can will follow.
Off the shelf cases and a 1-8" twist barrel spins the almost 600grs. to 1,430 ft.lbs. of thump at the muzzle with 1,050fps. But, it's only good if you want/need a stick fully dedicated to subs and are in love with the spendy Lehigh brass bullets. I do and I am.
Here are the numbers. And yea, at 250yds that aerodynamic hunk of brass will drop a wee bit over five (5) FEET with a hundred yard zero on the gun. You'll need a rangefinder and a scope with enough elevation!
<span style="text-decoration: underline">Input Data</span>
Ballistic Coefficient: 0.630 G1 Caliber: 0.458 in
Bullet Weight: 582.0 gr Bullet Length: 2.414 in
Muzzle Velocity: 1050.0 ft/s Distance to Chronograph: 10.0 ft
Sight Height: 1.50 in Sight Offset: 0.00 in
Zero Height: 0.00 in Zero Offset: 0.00 in
Windage: 0.000 MOA Elevation: 0.000 MOA
Barrel Twist: 10.0 in Twist Direction: Right
Temperature: 0.0 °F Pressure: 29.92 in Hg
Humidity: 0.0 % Altitude: 0.0 ft
Vital Zone Radius: 5.0 in
<span style="text-decoration: underline">Output Data</span>
Elevation: 16.959 MOA Windage: 0.000 MOA
Atmospheric Density: 0.08629 lb/ft³ Speed of Sound: 1051.0 ft/s
Maximum PBR: 139 yd Maximum PBR Zero: 117 yd
Sectional Density: 0.396 lb/in² Stability at Muzzle: 1.606
<span style="text-decoration: underline">Calculated Table</span>
Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s) (in) (MOA)
0 -1.5 *** 0.0 *** 1051.9 1.001 1429.6 0.000 0.0 ***
25 1.9 7.4 0.0 0.1 1038.1 0.988 1392.3 0.072 0.0 0.0
50 3.4 6.5 0.1 0.2 1024.9 0.975 1357.3 0.144 0.0 0.0
75 2.8 3.5 0.2 0.3 1012.5 0.963 1324.6 0.218 0.0 0.0
100 -0.0 -0.0 0.4 0.4 1000.7 0.952 1293.8 0.293 0.0 0.0
125 -4.9 -3.8 0.6 0.4 989.4 0.941 1264.9 0.368 0.0 0.0
150 -12.1 -7.7 0.8 0.5 978.7 0.931 1237.7 0.444 0.0 0.0
175 -21.5 -11.7 1.1 0.6 968.5 0.921 1212.0 0.521 0.0 0.0
200 -33.2 -15.8 1.4 0.7 958.7 0.912 1187.7 0.599 0.0 0.0
225 -47.3 -20.1 1.7 0.7 949.4 0.903 1164.6 0.678 0.0 0.0
250 -63.8 -24.4 2.1 0.8 940.4 0.895 1142.7 0.757 0.0 0.0
275 -82.7 -28.7 2.5 0.9 931.8 0.887 1121.8 0.837 0.0 0.0
300 -104.2 -33.2 3.0 1.0 923.5 0.879 1101.9 0.918 0.0 0.0