Some Interesting Data

I noticed, while playing around with the calculators on Airguns of Arizona, that there is an advantage to middle weight pellets vs. heavy pellets.

Look at this:

9.3 grain RWS Supermag pellets (.177 caliber)
Ballistic Co-efficient = 0.012
Average muzzle velocity in the Diana P5 Magnum: 450 fps (4.18 FPE)


8.2 grain RWS Meisterkugeln pellets (.177 caliber)
Ballistic Co-efficient = 0.010
Average muzzle velocity in the Diana P5 Magnum: 507 fps (4.68 FPE)


Not only do the lighter pellets provide slightly more power at the muzzle, they retain it better initially as well:


Supermag retained velocity at 10 yards = 406 fps (3.4 FPE)

Supermag retained velocity at 20 yards = 365 fps (2.75 FPE)

Supermag retained velocity at 30 yards = 329 fps (2.24 FPE)



Meisterkugeln retained velocity at 10 yards = 447 fps (3.64 FPE)

Meisterkugeln retained velocity at 20 yards = 395 fps (2.84 FPE)

Meisterkugeln retained velocity at 30 yards = 349 fps (2.22 FPE)


At shorter ranges, the medium weight pellet performs better, but starting at 30 yards (which is long range for a pistol like the P5) the heavy pellet starts to edge out the medium weight pellet. That's because FPE (Foot Pounds of Energy delivered) is a delicate balance between velocity and mass; once the pellets are traveling at roughly the same speed (329 fps vs. 349 fps), the mass of the heavier pellet is going to enable it to deliver a harder punch. The heavy pellet is traveling 20 fps slower at 30 yards, but still hitting harder.

However, at shorter ranges, the medium weight pellet's advantage is that its lighter weight helps it to retain more velocity.

CONCLUSION: Under 30 yards, the medium weight pellet packs more of a punch. At 30 yards plus, the heavy pellet has the edge.

I just thought I would make a note of this. I love examining data like this. It really helps one gain a better understanding of the physics involved in this enjoyable sport.