Here's a list of ammunition for the 157mm Rifles used on the Mengwa. Note the see-through of the complete Practice Round at the top; the rounded object on the back end is the countermass, a sponge-like object that is about 85% water, and absorbs most of the backblast and shock. The propeelnt charge is sort of short for an RR round, but the large daimeter allows for a large volume of propellant.
As with the 150mm howitzer ammo used by the Tigerwolf MBT, most of the rounds are rocket-boosted to improve range, velocity, and hitting power.
The employment of the gun-launched guided missiles is very important, because they make a seperate missile-armed Tank Destroyer unneccessary. Exept for the Flechette round, and Cannister round, all of the other rounds are rocket-boosted in flight (then again, the missiles are technically rocket-PROPELLED in flight).
All of these rounds are essentially slightly cut-down versions of the ammo used in the Tigerwolf's gun, so if you want to see what thier effects are, go here; http://www.furaffinity.net/view/596962/
The rocket-boosted rounds have a Ca. 5000 feet range, while the Flechette is effective out to 1.5 miles, and the Cannister 3000 feet. The rifle-launched Talon has a range of about 3.5 miles, while the rifle-launched Fang is effective out to 5 miles.