Firing 35 Whelen out of the Mini-G.
The ammo I used was 250 grain rated at 2600 FPS in a 24 inch barrel.
I fired 10 rounds and received an average FPS of 2428 FPS.

Ammo rated at 2600 FPS in 24" barrel
Fired from Mini-G 2428 FPS in 16" barrel
I lost 172 FPS or about 7%
The ammo would deliver 3754 FLBS in 24" BRL
It delivered 3346 Foot LB's in the 16" BRL

At 140 yards the groups were just under 2" off a rest.


Here's some .308 data
150gr bullet has approx velocity of 2800 fps. 2,611 foot pounds of energy 24" barrel
Out o f the Mini-G
barrelAverage FPS 2666
Foot pounds of energy 2368

30/06 Mini-G

Done by a third party.

AMMUNITION
VELOCITY
ENERGY
GROUP
Federal American Eagle 150-grain FMJ
2705
2437
1.56”
PMC 150-grain Soft Point
2652
2343
1.08”
Remington 150-grain Metal Case
2657
2351
1.18”
Greek 150-grain FMJ Surplus
2528
2129
1.99”

All groups were fired from a seated rest with targets set up at 50-yards with five shots to a group. Velocities were measured with a PACT chronograph and expressed in Feet per Second. Energies are listed in Foot Pounds of Energy.


These are NOT my numbers. These numbers were given to me by a third party using a Mini-G with a TE of 4 and ME of 1.