32 AIRGUN WORLD http://www.airgunshooting.co.uk
only real visible difference is that it’s coated in
a copper coloured veneer – we cut one open
- and as it measures just 0.1mm shorter than
the JSB, it will be interesting to see how they
perform against each other.
Lastly, the ‘control’ pellet is a bog-
standard AA Diabolo Field at 8.4gr, although
it could be any traditional domed pellet
around the 8-9gr weight that works well with
your airgun.
TESTING AND RESULTS
As always, testing was carried out at 25-ish
metres, into 40mm thick blocks of warmed
terracotta clay.
The heavyweight Piledriver was first into the
breech of the excellent Daystate Pulsar, and
allowing for the astonishing 10 inches of
holdover required at just 25m, it was able to
deliver quite reasonable groups. From a
ballistics standpoint, it arrived with a velocity of
343fps losing a total of 97fps on exit, which
doesn’t look promising. In regard to energy
dissipation, the Piledriver sheds just 2.67 ft.
lbs. of energy, which again, isn’t getting the
ballistic juices flowing.
The JSB Exact Beast was next on the test
sheet and surrendered 159fps of velocity, and
85 ft.lbs. of energy, which was quite a
reasonable result for a pellet of this weight.
The third.177 pellet was the H&N Rab
Power Mag. Although only a fraction lighter
than the Beast, the Rab delivered an almost
identical 158fps, with a similarly comparable
4.26 ft.lbs. loss in energy.
Finally, the ‘control’ pellet. You might well
ask why this 8.4gr pellet is here amongst the
heavy weight contenders, but if you’re up on
ballistics, or have read the introduction to this
article, then I’m willing to guess you have
something of an idea – it totally wrecked the
other pellets in this test!CONCLUSION
So, the Beast and the Rab are pretty much neck
and neck in second and third place, with very
little to decide, and although the Beast was
slightly up on velocity and energy lost, it’s worth
noting that with the Pulsar, which is quite pellet
friendly, the H&N was a true ‘Beast’ to get to
group, and it took more than a few attempts to
get a clean shot through the R2a Chronographs.
If your rifle gets on with these then great, but
otherwise there are others you could be looking
at, like the H&N Piledriver, but excellent though
it might be in an FAC air rifle, in a 12 ft.lbs. gun,
the numbers just don’t stack up. However, they
do confirm the principles of ballistic coefficient
because this heavy pellet gave up very little of its
velocity or energy to the target material.
So to this month’s winner: Ladies and
Gentlemen, and those of you with an
unspecified or fluid gender, we give you the
Air Arms Field Diabolo. This diminutive 8.4gr
pellet totally outperformed all of the heavy and
medium weight contenders in regard to
accuracy and ballistic capability, and it did so
thanks to the principles of sectional density,
coefficient of form, and ballistic coefficient.
Don’t you just love it when the maths add up! PELLET TESTING - BALLISTIC COEFFICIENT
Some entry holes are more impressive than others. Which is better, a larger or smaller exit hole?
A visit from Mr Dremel revealed the lead beneath
the copper veneer.Mr Dremel should reveal the inner secrets of the Rab Mag. The R2As can take a heck of a lot of grief and perform.