Pellet velocity versus accuracy test: Part 2
by B.B. Pelletier
Today, I’m testing the accuracy of my Whiscombe running at full bore. This is the end of Phase One of this experiment. Next time, I’ll reduce the velocity of the rifle and retest all four pellets.
The shooting was done indoors at 25 yards. The Whiscombe is scoped with a Simmons 4-12x scope, and I did use the artillery hold, even though the rifle is recoilless, because John Whiscombe told me to.
KRAAK! That’s what the Beeman Devastator pellet says when it goes downrange at 1,200 f.p.s. It sounded as loud as a .22 long rifle shot, though I’m sure it wasn’t.
I was all set to show you a blown group and then lecture you about the evils of diabolos breaking the sound barrier, only these pellets didn’t seem to cooperate. They all wanted to go to the same place, which upsets all sorts of apple carts.
How about that! Apparently, these Devastator pellets missed the memo that they aren’t supposed to be accurate at high velocity. The 10-shot group at 25 yards measures 0.903 inches. While it’s not a super group, it’s also not bad for a hunting pellet going 1,200 f.p.s.!
Crosman Premier lites
Next up are the Crosman Premier lite pellets. They had the good manners to behave as a diabolo pellet should, by grouping 10 shots in 2.385 inches. Though only a single pellet opened the group to that size, the other nine were still more scattered than the Beeman Devastators.
The Premiers also broke the sound barrier, but the sound wasn’t as loud as the Beeman Devastators. I’m thinking the Devastators were also detonating, which is something the JW75 hardly ever does.
If you will recall, Beeman Kodiaks brought the rifle’s velocity down to just under 1,000 f.p.s. That’s still in the transonic region and too fast for optimum accuracy — at least according to the popular theory. Kodiaks turned in the second-largest group of this test, though it was much closer to the best group than to the worst. Ten pellets went into a group measuring 1.055 inches.
Eun Jin heavies
The last pellets I tested were the 16.1-grain Eun Jin pellets. Usually, I think of Eun Jins as an okay pellet that delivers maximum power; but in the JW75, which is a spring-piston rifle, they’re the weakest by a considerable margin. However, they’re also down out of the transonic region where all the bad things happen, so I guess I shouldn’t be surprised when they turned in the best group of the test. Ten pellets went into a group measuring 0.755 inches, or just about three-quarters of an inch. And 7 of those 10 pellets went into a smaller group that measures just 0.413 inches across.
While I was shooting, I noticed that with both the Premiers and the Eun Jins, the first few pellets landed away from the principal group. That lends a lot of support to the viewpoint that barrels have to be conditioned by shooting a few pellets through them before they can be expected to perform at their best.
As a result of this observation, I’m going to run this exact test one more time with a slight change. Before I shoot a group for the record, each new pellet will be fired three times. That way I can be sure we’re seeing the absolute best this rifle can give us at this power level with these pellets.
I was very surprised by the performance of the Beeman Devastators. They didn’t act as I felt sure they would. And I will be very curious to see what they do in the next test. I don’t know what’s happening, because I’ve seen high velocity scatter pellets in the past; but perhaps the introduction of the Whiscombe has changed something. We shall see.