Airgun Guru: should every airgun owner have a chronoscope?

PUBLISHED: 11:26 21 October 2016 | UPDATED: 11:26 21 October 2016

From the least expensive to the top of the line, there are chronos to suit all budgets

From the least expensive to the top of the line, there are chronos to suit all budgets


A reader is thinking of adding a chronoscope to their kit bag, but is unsure whether it merits the money, considering it may not be used much

Q: I have a birthday coming up soon, and have decided to treat myself to something to enhance my airgun shooting. I’ve already got rifles and scopes, so was thinking of a chronoscope. The one thing that’s always held me back from buying one in the past is the thought that they aren’t cheap, given the occasional use they are likely to receive. Can you justify spending £100-plus?

The Airgun Guru says:

In my opinion, every airgun owner should own, or at least have access to, a chronoscope. Most gun shops and airgun clubs have chronoscopes for the use of customers or members, but if you’re not a club member, it can be inconvenient to test your rifle. It’s far better to have one at home.

The most obvious and important reason for owning a chronoscope is to ensure your airgun is safely within the 12ft. lb. limit with a range of pellets. Airgun muzzle energy, both spring airguns and PCPs, can vary hugely according to the pellet it is shooting.

Chronos like this Caldwel Precision can be used down range as well as at the muzzleChronos like this Caldwel Precision can be used down range as well as at the muzzle

Spring airguns generally give higher muzzle energy with lighter pellets, PCPs with heavier pellets. This is only a generalisation and certain pellets can buck the trend, sometimes for reasons we still don’t understand, so the only way to be sure a rifle is legal with a pellet is to test it.

The other reason to test the rifle regularly – it’s a health check for your airgun and can warn you of developing problems.

The lowest cost chronoscope is the Combro CB625, a small unit that is attached to the barrel near the muzzle. At under £50, these are great value for money, best suited to PCPs due to the recoil of spring airguns, which can make it difficult to keep the unit firmly attached to the barrel.

Other chronoscopes tend to retail at two to four times the price of the Combro. What they offer is a wide aperture to shoot through, so you can measure the pellet velocity at longer ranges to see how much energy the pellet carries, or use the application in Hawke Chairgun Pro to calculate the pellet’s ballistic coefficient, essential for plotting trajectory.

When budgeting for a chronoscope, allow extra for a jeweller’s scale to weigh pellets, because the weight of pellets can differ considerably from the weight marked on the tin. If you’re checking your airgun is legal, it’s essential to know the correct pellet weight.

Are chronoscopes worth the expense? An unqualified yes. Knowing your rifle is performing correctly is worth a lot, but knowing it’s legal is priceless.

Oh, and Happy Birthday!


More advice from the Guru:

AirGun Guru: buying a second hand rifle

Airgun Guru: Recoil

Airgun Guru: Stop your rifle going rusty

Airgun Guru: pellet power

Airgun Guru: how often do airgun barrels need to be cleaned, and what’s the best way of cleaning them?

Latest from the Airgun Shooting