These might actually sell better if they had listed them under large bore ammo 40 mm.$1200 for 97 rounds on GB.
The Marine trading cadre at Carswell uses a 40mm air soft round without the BB’s. They stuff a weighted tailed nerf football with built-in whistles in the nose down the front of the barrel. Cheap, with good range.
We had a blast shooting the things during MOUT/CQB FISH exercises in the old housing area.