The .177cal/4.5mm H&N Prometheus shoots very well in my 70 year old Benjamin model 317 pneumatic air rifle!
Crosman's lead free .22cal/5.5mm Monster!
I love this AirGun ammo!
I feed it to my Crosman 2240, 1322's, Diana Chaser co2 rifle and my Beeman P1 Magnum spring piston air pistol!
The 8.5 grain penetrators are devastating when shot by Magnum power AirGuns.
The .177cal/4.5mm "fast flight" 5.4 grain penetrators from Crosman are the perfect length for the Crosman's 357 Co2 revolver, and any breach loading or break barrel type of AirGun.
Trevor Adams reviewed the original "Prometheus" ammo a couple of decades ago:
