Which is Best?
Gary Wain investigates the perennial .177 versus .22 debate
Gary Wain revisits an old chestnut - which calibre for accuracy, .177 or .22?
Having finished writing February’s article, I felt almost as if my mind had been read when our esteemed editor, Terry Doe, pointed me in the direction of a letter that had been sent in by one of our readers, a Mr Robin Lambert. In his letter, Mr Lambert said he would be interested in seeing a real-world test between .177 and .22 that would settle the argument between those who insist that .22 holds its energy better and those who are adamant that .177 retains more power – either that, or solve the Middle East crisis.
Well, Mr Lambert, and I guess many others out there who might be wondering the same thing, let’s see if we can at least shed some like on this perpetually thorny subject, but be warned, I suspect this particular rabbit hole is quite deep.
In order to understand the answer, you must first determine exactly what the question is. To do this, the first thing we need to do is define what exactly we mean by ‘energy’ and ‘power’. Now, I should perhaps point out that I am neither a practising nor armchair physicist, and so my definitions and principles should be appreciated as such. What I will do, though, is attempt to link an understanding of the principles with what we shooters need to know, and with luck, relate that to the question in hand.
So, with the above caveat in mind, the laws of physics inform us that energy is associated with either motion (kinetic energy), or the ability to create motion (potential energy). We’re further enlightened that energy can neither be created nor destroyed, but only changed from one form to another. This concept is known as the principle of conservation of energy and is acclaimed as the first law of thermodynamics. For the physicists amongst you, I appreciate that this is not true,
“this is simply too much to address within the scope of a single article”
strictly speaking, but can be broadly accepted within a closed system. In shooting terms we think of energy as the amount of kinetic energy imparted to a projectile at the muzzle, and it is typically measured in foot-pounds, abbreviated here to ft.lbs. It is widely appreciated that the heavier the pellet and the faster it is moving, the higher its muzzle energy and the more damage it is capable of doing. Do please note that velocity plays an important part in this equation. The equation for calculating kinetic energy is Ek=1/2mv squared, where E=Energy, V=the velocity of the bullet, and m=mass. Riveting though this formula is, we’re lucky in that when programmed with the mass of a pellet in grains, chronographs are able to calculate the energy in ft.lbs. automatically.
Power is a little harder to define. I suspect that neither you, I, or indeed, Mr Lambert, are thinking of power in regard to classical physics, wherein it is defined as ‘the rate of doing work’. More simply understood as the amount of energy transferred in a given unit of time, and although this definition might tip its cap vaguely in the direction of terminal ballistics, more likely we’re thinking of that much debated term ‘stopping power’. Stopping power defines the ability of a projectile to inflict sufficient trauma to the target to incapacitate it immediately. What we’re talking about here is the terminal ballistic effect and the ballistic wound channel.
From the tests I’ve already done, we know that a pellet produces a cavity within the subject target matter. There are two types of cavity; the first relates to the actual diameter of the pellet, and the latter to the temporary displacement of the target material as the pellet passes through. In the experiments we’ve done with ballistic clay, to some extent we have been able to observe and measure these temporary ballistic effects in the form of the plaster of Paris core samples.
This leaves us with two distinct sets of units to measure. The first is the energy that a pellet possesses, not only at the muzzle, but also at ever-increasing distances, and the second is the energy that pellet is able to impart to the subject matter. As you may have already guessed, this is simply too much to address within the scope of a single article, so I will first look at the concept of energy as questioned by Mr Lambert, and in particular the manner in which this is affected by distance. As we will be gathering data on velocity, we will also look at how this is affected by distance.
So, we come to testing. Armed with my trusty R2A chronographs, courtesy of Blackpool Air Rifles, I set up a range to measure the velocity and energy of pellets from both .177 and .22 at
“Initially ,I thought it would be a great idea to measure every metre”
distances between one and 40 metres. As with all testing, it’s important to eliminate, or at least mitigate as many variables as possible, and thanks to Terence Logan, and the team at Daystate, I was able to get loan of a .22 Pulsar to complement my coveted .177 Pulsar. True to his word, Terence had actually provided me with a .22 Pulsar with a muzzle energy that was to within .02 ft.lbs. of my .177. Not only that, but Terence had also supplied it with a matching MTC Viper Pro Tactical 5-30 x 50, and an identical, hard-wearing, black laminate stock. When it came to pellets, I was aware from previous testing that the Pulsar performs well with a range of pellets, but like many rifles, seems to love the AA Diabolo Field, so I would use the 8.4gr in .177 and the 16gr in the .22.
Initially, I thought it would be a great idea to measure every metre, from zero to 40 metres, but as each shot required me to get up, walk to the chrono’, record the value, lift the heavy work bench one metre further away, walk back, sit down, re-aim and then repeat, to be honest, by the time I got to the 25 metre mark I was totally knackered, Forget biathlon, they ought to have this as an Olympic event. I quickly worked out that by the end of testing both rifles I’d have walked 3280m, so I decided to agree with Mr Lambert and just measured every five metres.
At the end of a full day’s testing, and an awful lot of walking back and forth, what had I learned? Well, although not a direct part of the question, let’s look at velocity first. From the real-world data obtained, it’s clear to see that the heavier 16gr .22 pellet is much slower than the lighter 8.4gr .177 pellet. That said, in the first 20m, the .22 pellet loses less velocity than the .177. However, .22 then loses much more velocity than the .177 between 20m and 40m. When we look at energy, measured in ft.lbs., we see that both pellets have roughly the same amount of energy up to the 20m mark, at which point .22 starts to lose energy at a faster rate than the .177 pellet. In practical terms, this was observed in the testing process because up to the 20m mark it was pretty easy to shoot both calibres through the small opening in the steel guard. Above 20m, I noticed that it was much harder to get the .22 pellets through than the .177 ones, as the damage to the guards will attest.
From the data obtained we can therefore confirm that that the lighter .177 pellet retains energy more readily than the heavier .22 pellet, a great deal of this being related to the higher velocity. Of course, the question is, what happens to this energy when the pellet impacts the target? I already strongly suspect that the .177 will surrender more of its energy more readily, as seen in the plaster-cast core samples, but in future articles I hope to put some figures together to allow us to see just how much of difference there is in the power delivered to the target on impact. As ever, if you’ve got any aspects of pellet testing or ballistics you’ve always wondered about, do please message us and we’ll do our best to look into it.
The steel baffles did their job and prevented an embarrassing call to Blackpool Air Rifles.
Forget biathlon – they ought to make shifting this lot 1m at a time for 40m an Olympic event!
How hard can it be at 1m?
What could be better than one Pulsar?
It might look sunny, but it was cold enough to snap a moustache off!
A Daystate Pulsar, MTC scope and rangefinder and I’m good to go.
Where are you putting your money – .177 or .22?
Which calibre proved the most troublesome?