Hot barrels and accuracy: mutually exclusive or not?


From years of anecdotal evidence, I was sure that when I asked does a hot barrel ruin a rifle’s accuracy? I’d come face to face with a big sign saying yes!

Instead I found the answer sitting on a fence, yes on one side and no on the other. I hate that.

It tuns out the real question is how much does heat affect accuracy? And the answer is different for every rifle! Nothing’s ever simple, eh?

In some rifles, accuracy goes out the window. In others, the change is hardly worth noting.

If you want to see the nitty gritty of the testing we did to learn this depressing lesson, check out the video. You’ll also get some advice about how much loss of accuracy really matters, and discover how to check your rifle’s accuracy when it’s hot.

Or if you want to jump straight to the spoilers, read on.

The testing was done on behalf of Eagleye Hunting Gear, who have commissioned an ongoing series of myth-busting gun videos.

What we found from testing a number of sporter-weight rifles is that all will shoot larger groups as heat builds.

However, some rifles are not nearly as badly affected as others.

The only way to know how yours will perform is to test it.

Hot barrel testing simply involves firing a large-ish number of shots as rapidly as you can while being as accurate as you can. Ideally, mount a camera near the target so you can see the progressive impacts and get an idea of how the barrel is behaving as it gets hotter and hotter with each shot.

Don’t over-do it or you may cause damage to the barrel by getting it way too hot. Fifteen shots should be ample to give you a sound result. Maybe less if there’s a dramatic shift.

Your first three shots set the benchmark for accuracy. The rest reveal how good or bad your rifle is at dealing with heat.

Why does heat affect accuracy?

Here’s a very quick lesson is the how and why of the matter.

When the metal of a barrel gets hot, it expands. Its physical structure is also altered.

As a result, the vibrations that ripple through the barrel during firing will also change. This means that when the projectile leaves the barrel, the muzzle is likely to be pointing in a different direction than it would under the influence of cold-barrel vibrations.

Hence your bullet goes in a different direction and hits somewhere else.

One day we’ll go into this in proper scientific detail, but this will do for now.


For your enjoyment and entertainment, Straight Shooting, Australia's 1st Digital Firearms Hub, delivers the latest information on guns, gear, issues and more, directly to your inbox.

Sign up now and you'll be automatically entered into our regular competition draws.

* Don't forget to also like us on Facebook & Instagram!

NOTE: Our system requires double opt-in. Please confirm your subscription by clicking on the link sent to your email. If you can't find it, please check your inbox or spam folder.

We don’t spam! Read our privacy policy for more info.


Please enter your comment!
Please enter your name here