What’s The Best Pellet Weight For My Airgun In .22 Caliber?
Many newcomers to the airgun world find the huge variety of airgun ammo confusing – or worse. What – they ask – is the best pellet weight for my airgun?
Pellet Weight Background
In fact, the answer to this question is becoming daily more complex. This is due to the rapid increase in interest in slugs as airgun ammo. In general, they’re heavier than pellets and require more power to shoot successfully.
Below: H&N Baracuda 18s are a quality .22 caliber pellet that perform well in many PCPs.
Added to this are the the remaining effects of the soundly-discredited airgun marketing philosophy that “higher muzzle velocity must be better”. According to this, no acceptable air rifle can be any use if it has a (claimed) muzzle velocity of less than 1,000 FPS.
In fact – so this line of thinking goes – 1,200 FPS or even 1,500 FPS JUST HAS to be best for your airgun. “Real men” wouldn’t settle for less…
Sadly, nothing could be further from the truth!
Unfortunately such hyper-velocities are primarily associated with .177 calibers. One issue is that these velocities may cause pellets to exceed the Sound Barrier (approximately 1,100 FPS) and thus cause an extremely-loud report – no matter what claims are made for the silence of the airgun in question.
Crossing the Sound Barrier also can do bad things to accuracy. We all want to hit the target we’re aiming-at, don’t we?
Above: The KalibrGun Cricket II Tactical is a powerful PCP that will give best results with heavy pellets or slugs. That’s Matt Coulter shooting.
The second issue is that best accuracy is generally achieved with lead pellets fired at a muzzle velocity of somewhere between 850 and 950 FPS. HAM testing proves this and it’s well-known to knowledgeable airgunners.
A third issue is that larger-diameter pellets – in .22 caliber, for example – are generally much heavier than those in .177 caliber. That’s just plain physics. They’re bigger and thus heavier.
It’s obvious to everyone that a heavier pellet would need more power to achieve a certain muzzle velocity – say 1,000 FPS – than a lighter pellet. It just makes sense.
That does mean, however, that we need to forget FPS as any sort of realistic measurement of airgun performance and settle – instead – for power: aka muzzle energy.
Below: Heavy pellets generally prove their worth at long ranges as they’re less effected by wind.
So, in order to understand the best pellet weight for my airgun, I need to know its muzzle energy. This information is readily available from manufacturers and dealers, so you should easily be able to find the information for your air rifle.
Muzzle energy is measured in units of Ft/Lbs. In the metric system, the unit is the Joule (J).
Unfortunately – like FPS – muzzle energy varies with the weight of the pellet that’s being fired. Generally, break-barrel air rifles will show their highest muzzle energy with the lightest pellets. PCPs and CO2-powered air rifles generally produce their highest power levels with heavier pellets.
Below: Apart from weight, there’s also pellet shape to consider, as we see with this range from Norma. But that’s another story altogether!
Many airgunners are buying PCPs these days and they’re not buying .177s. (You can see that from the number of new PCPs designs being introduced with no .177 caliber version).
So it makes sense to look at weight of .22 caliber airgun ammo – both pellets and slugs – and understand how that relates to the muzzle energy (power) that’s required to achieve FPS in the 850 – 950 FPS range.
Next, it’s necessary to say that – just because a certain pellet provides an appropriate muzzle velocity – that does not mean that it’s bound to be accurate in your air rifle. There will still be experimentation needed by the shooter to discover if your air rifle’s barrel “likes” that specific pellet.
But at least you’ll be looking in the right range to find the best pellet weight for my airgun.
Ammo Weight And Muzzle Energy Relationship
The simplest way to visualize the relationship between ammo weight and muzzle energy is to draw a graph. With Muzzle Energy on the vertical (y) axis and pellet weight on the horizontal (x) axis, we can then calculate and plot lines matching the appropriate relationship for muzzle velocities of 850 FPS and 950 FPS.
The chart below shows this. Here we show pellet – and slug – weights from 10 to 42 Grains and muzzle energies from 10 to 90 Ft/Lbs.
The example shows how we read off appropriate pellet weights for a .22 caliber PCP air rifle with a 30 Ft/Lbs muzzle energy.
So – in the case of such an air rifle, it’s likely that 14.66 Grain H&N Field Target Trophy pellets would be suitable, as would 18.13 Grain JSB Jumbo Heavies. You could also try 21.14 Grain H&N Baracuda Match pellets, as they’re close and would give around 800 FPS. That’s a little slow but may be OK.
But if you have a yearning to try heavy slugs with more than 30 Grains weight – after all, the high BCs must be good, right? – you can see from the graph that such slugs need a power of somewhere in the 50 Ft/Lbs to 60 Ft/Lbs range.
That’s probably not going to give a great result with your 30 Ft/Lbs air rifle. In fact, the slug will have a muzzle velocity of something like 675 FPS…
Pellet Weight And Muzzle Energy Relationship For Break Barrel Air Rifles
Break barrel spring/piston and gas ram air rifles generally have relatively low muzzle energies. This means that they perform best with lighter pellets. For this reason, HAM has not tested many break barrels in .22 caliber, concentrating instead on .177 caliber guns.
However here is the graph of actual performance for a typical .22 caliber spring/piston gun. In fact, it’s the HAM test data from the Gamo Swarm Maxxim. Yes I agree the data is somewhat “ragged”, but it makes the point nonetheless, as the trend line shows.
As you can see, the Muzzle Energy tends to fall with increasing pellet weight. This is normal for spring/piston and gas ram air rifles.
You can see full details in our test review.
This tells us that most spring/piston and break barrel guns are unlikely to do well with slugs as the lightest .22 caliber slugs available in the US market are the 20.3 Grain Daystate Howlers.
Pellet Weight And Muzzle Energy Relationship For PCP Air Rifles
Here is the same chart for a typical .22 caliber PCP air rifle. This time the data is from our comprehensive HAM test review of the Umarex Gauntlet 2 in .22 caliber.
As we can see, the muzzle energy rises significantly with increasing pellet weight. This is normal for PCPs.
In this case we can suggest that – although the Gauntlet 2 gave excellent accuracy across the whole range of test pellets (even the lightest) – it gave best accuracy with the heaviest pellets.
This, plus the power levels demonstrated in the test, indicates that the Gauntlet 2 could be a candidate for use with heavier slugs up to around, say 30 Grains in .22 caliber.
Best Pellet Weight Chart
This chart is actually the same as the first one above, but a just part of it. It just focuses on the weights of pellets (rather than slugs) to make it easier to read and use.
Best Slug Weight Chart
And here’s another version of this chart showing the weights applicable to .22 caliber slugs. As you can see, you’ll be needing a VERY powerful PCP to shoot 40 Grain slugs – somewhere in the range of 65 Ft/Lbs to 80 Ft/Lbs
Conclusion – The Best Pellet Weight For My Airgun
Using the charts in this article, you should be able to make an initial assessment of the pellet weights that are likely to work well with your air rifle.
However please remember it’s still only a guide…
Every individual airgun will have its own specific ammo preferences, so you’ll need to try a variety of pellets and slugs and make your own tests. There’s bound to be outliers to this general guide. But I hope it helps “get you into the ballpark” with choosing the best pellet weight for your airgun, thus saving some time, cost and frustration.
Good luck and have fun!