Barrel Life: A Screed of Old Standby & the Math of the Matter

Once the start is thoroughly worn you're unlikely to get minimally useful performance much less acceptably consistent performance. The rest of the rifling, the bore, can and usually does have a much longer "life" than the muzzle end or the rifling origin. There's a lot of technically detailed yuk to explain that but it's more math than needs to be written and nobody really cares to read that kind of stuff except physics geeks and materials scientists.

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Figure 6. Counterbored rifle muzzle.

If a muzzle is heavily eroded you might be able to lop a couple inches off and have it re-crowned and it might just last a good while longer. Could also back bore it, that is drill into it to make a new crown deeper in. Depends. If the throat is burned you can do basically the same thing. This is called "setting back" the barrel. You lop a couple inches off both ends, rechamber, re-thread and reinstall the barrel. I've never known anyone that's actually done that. Probably because as I got old enough to replace barrels they were already something of a commodity item. Not nearly as big a pain to deal with as they used to be. Also, at least in the sports I compete in, the standard practice seems to be toward chasing the lands (seating bullets gradually longer and longer to keep the jump to the rifling the same) as far as you can and then tossing the pipe outright and simply getting another.

So what you're probably looking for is how to maximize barrel life. Well, I'm sure there are 100 opinions but there is at least one plain fact, Rule #2. I won't judge your rules if they're different. I bet they'll be nearly identical though. Here's what I do. Keep in mind, I'm not a big hunter. I'm a match/competition shooter and part time instructor. I shoot high volume when I shoot and shots are almost always done rapid fire.

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Figure 7. Drop-in barrels are inexpensive, common and easy to install.

As far as when to clean a rifle: By my way of doing things it is when it starts opening up the group sizes. Fouling reaches something of an equilibrium at some point where it doesn't get much worse for each shot. This is after a period of fouling the barrel till it shoots "normal". I find after a certain number-range of rounds my groups stabilize and my velocity SD's thin out a bit. So I use that area to my advantage. Most of my match guns usually end up getting thoroughly cleaned after 200-400 rounds or so. If you want to clean it after a little range day, run a patch with some Hoppes #9 or CLP on it till they come out clean, then another patch dry and call it even with a final light coat of gun oil.

My Rules for Maximum Barrel Life:
1. Don't clean too often. Clean when it actually needs it.
2. Do NOT shoot your gun hot. If it's starting to warm up, open the bolt and set it aside. This is actually Rule #1 but I like the existing Rule #1 where it's at. Shooting it hot will burn out the throat in no time.
3. Don't clean from the muzzle if you can possibly help it. This helps avoid damage to the crown. Avoid anything going across the muzzle in a direction bullets don't go.
4. Don't push your bore brush all the way through the muzzle. When it gets there and the tip has passed partially through, pull it back. Same for patches.
5. Never ever think that twisting/spinning a brush in your bore is a good idea. Any twisting it needs to do, the rifling will make it do.

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Figure 8. This is a murder weapon from a rifle barrel's perspective.

6. Don't get aggressive with the physical part. Find a better life through chemistry. Chemical agents should be used to remove metal (copper/lead) fouling. Brushes and patches with fairly mild cleaners/solvents easily remove carbon. This is another reason to not clean deeply too often. Chemical agents for copper fouling are extremely harsh as a rule, overuse and misuse will damage barrels.
7. Keep track of how many shots you can take before needing a cleaning. Track that over time and watch for changes. This is your barrel talking to you.
8. Don't shoot steel jacketed/bi-metal jacketed bullets if you like your barrel and want long barrel life. They're pretty darned hard on barrels.
9. Use a coated cleaning rod like a Dewey Rod and use an bore/action guide. These little things add some kit and cost but they help by keeping things lined up cleanly right off the bat, helping to prevent damage.
10. Seriously, don't shoot your gun hot.

Above all, remember that like any tool rifles require maintenance but much like common hand tools, not all that much. Wipe em' down when they're dirty. Keep them away from moisture. Don't let caustic agents spend much time in contact with them. Don't get them too hot. In general, the same rules you'd apply to a Snap-On box end wrench generally apply to a rifle barrel. You don't have to wear white gloves. These are tools that can take some rough use. You do want to have them in a condition for immediate use after you put them away so a quick wipe down, a patch set through the bore and being properly put away should suffice until it's obvious that it's time for a more thorough cleaning.

All of the above is old hat for most of the folks that will read this.