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rsterne · Moderator

I got the opportunity today to do some Ballistics Coefficient and accuracy testing today with heavy pellets in my 22XX PCP.... I cranked the power up to the current maximum (~31 FPE) and shot 5 shot strings through my Chrony at the muzzle and at 25 yards.... then calculated the BC for each pellet using ChairGun2:

JSB Heavy 18.0 gr. @ 898 fps - BC = 0.039
H&N Baracuda (Kodiak) 21.0 gr. @ 821 fps - BC = 0.051
H&N Rabbit Magnum II 24.8 gr. @ 749 fps - BC = 0.072
Predator Big Boy 26.0 gr @ 738 fps - BC = 0.030
Eun Jin Domed 28.7 gr. @ 699 fps - BC = 0.048
Eun Jin Pointed 32.4 gr @ 653 fps - BC = 0.044

Also tested (because I didn't have them when I did earlier tests) with the gun dialed back to previous power ~ 25 FPE:

Beeman Hollow Point 14.3 gr @ 890 fps - BC = 0.022
Hatsan Domed 14.3 gr @ 884 fps - BC = 0.021

As you can see, the new H&N Rabbit Magnum II has the best Ballistics Coefficient, and the highest I have ever seen for a pellet.... However, it is still a long way from that of a .22 Short subsonic 29 gr. which is 0.122.... I tested a couple of 14.3 gr. pellets at close to 1000 fps, and I notice the Ballistics Coefficient is dropping off significantly at those velocities.... Even the 18.0 gr. JSB Heavy had a 10% poorer BC at 900 fps than it did at 820.... On the other hand, the Kodiak was almost 10% better at 820 fps than it was at 750.... Perhaps there is a "best" velocity when it comes to BC at around the mid 800 fps range, I don't know.... Shocked

I then shot some 5-shot groups from the bench at 20 yards with the following results, pellets listed best to worst:

JSB Heavy - 0.4" CTC
H&N Baracuda - 0.5" CTC
Predator Big Boy - 0.5" CTC
Eun Jin Pointed - 0.7" CTC
Beeman Hollow Point - 0.8" CTC
EunJin Domed - 0.9" CTC
Rabbit Magnum II - 3.7" CTC and 2" to the left!
Hatsan Domed - 4.0" CTC

All the pellets produced acceptable to good accuracy, enough for further testing except for the Hatsan and the new H&N Rabbit Magnum IIs.... I have read in another thread that members are not happy with the accuracy of these new, non-waisted H&N pellets, and unfortunately I have to second that assessment.... too bad, because their BC is excellent.... Rolling Eyes

Bob