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Of Barrels And Accuracy

By Jon R. Sundra

The procedure for the breaking-in of a new barrel is surely one of the most controversial subjects among accuracy-conscious shooters and hunters. Generally speaking, those who consider a break-in regimen to be critical are custom barrel makers and benchrest shooters. But there is widespread disagreement as to specifics.

Some would have you shoot and clean after each shot for as many as 20 rounds, followed by five 3-shot groups with cleanings in-between, followed by incense-burning and incantations to the barrel gods. At the other extreme are those who believe that the normal process of sighting in a new rifle and finding an accurate handload or factory load will put more than enough rounds through a barrel to “break it in” before they even think about cleaning it, and then they do it purely out of guilt!

At the risk of oversimplifying, there are three basic ways to break in a barrel other than simply shooting it:

  • Repetitive shooting and cleaning
  • Fire lapping
  • Hand lapping

The shoot-clean, shoot-clean routine needs little explanation. The bullet itself serves as a lap, with the passage of each bullet contributing to the reduction and hopefully the elimination of any microscopic burrs and rough spots, and the cleaning after every shot or three prevents any build up of copper fouling.

Fire lapping requires handloading and consists of hand rolling bullets between steel plates coated with mild abrasive pastes ranging from 320 to 600 grit. Rolling the plates under hand pressure alone is enough to imbed the abrasives into the bullet’s bearing surface. Using moderate pressure handloads, each bullet sent down the bore essentially accomplishes the same end as the shoot-clean process, only faster.

Hand lapping consists of a lead lap precisely sized to the bore and attached to a cleaning rod. Using these same lapping compounds, the lap is manually run back and forth for as long as thought necessary, which can be five minutes or 30. Some proponents believe that a lead lap isn’t needed, and that all it takes is tight-fitting cleaning patches soaked in lapping compound, and lots — like hundreds — of passes in the bore.

All the aforementioned procedures are best done with a bore scope monitoring the process, because any of them can be overdone and cause more harm than good relative to barrel life. What is so paradoxical is that there are so many highly credible and successful competitive shooters, even record-holders, who say the various barrel break-in ceremonies are just that – ceremonies to instill peace of mind.

One must keep in mind, however, that many of the pricier production and semi-custom rifles which now come with MOA guarantees and 3-shot group targets, have had several rounds put through them. If it’s a 1/2 MOA guarantee, chances are that quite a few rounds have been fired before the gun is shipped. If it’s a pricey custom rifle, you can bet the barrel has been lapped, so any break-in machinations likely will do nothing but reduce its accuracy life.

I’m a minimalist when it comes to breaking in a new barrel. If it’s a personal rifle that I’ve put together and intend to use in the field, I’ll shoot five shots, cleaning after each, and that’s it. However, if I see a degradation of accuracy during handload development or factory ammo samplings, I’ll clean barrel until I get a white patch in, white patch out.

I have to say, though, that hasn’t happened very often, especially over the last couple of decades. If truth be told, today’s rifles, even the “value priced” ones, have remarkably good barrels, good enough that if one tries four or five factory loads, chances are at least one will shoot 1 to 1/2 MOA. On paper at least, that means the gun is capable of 7 1/2-inch groups at 500 yards, which is well within the vital zone of a whitetail deer. Is that good enough for any kind of competitive shooting? Hell no, not even close.

But I’m talking hunting rifles, which I venture to say are what interests most of you reading this deathless prose. More than 95 percent of the shooting I do is testing new rifles, and when a gun arrives, I simply give the barrel a routine cleaning before heading to the range. And like I said, the few rounds expended zeroing-in the scope and the trying out of a few different loads is usually enough to reveal a gun’s potential. If a rifle just doesn’t seem to want to shoot, it’s usually a bedding problem. It’s rarely a bad barrel or a barrel that isn’t broken in.

Now competitive shooters, especially the benchrest crowd, are a different breed. To these guys, a difference of .050-inch in aggregate group size on a 100-yard target can be the difference between first and tenth place. Rebarreling a competition rifle two or three times in a season is not rare among active shooters.

There is nothing these guys won’t do barrel break-in wise if they think it will gain them a few thousandths on paper. Some are less fanatical than others, but in either case, they are in the same boat as we hunters: they can’t undo whatever break-in ritual they performed to see how that barrel would have shot had they done nothing.

Though the break-in process is different from barrel cleaning, the two are so closely intertwined. You can’t address one without at least giving a nod to the other. Like break-in procedures, opinions on how and when to clean a barrel vary widely. It’s safe to say that hunters are less demanding than target shooters. I’m of the school that says if it ain’t broke, don’t fix it.

When testing a new rifle, I make sure it’s clean before taking it to the range, but then I rarely clean it before I’m through shooting it, which is usually around 60 to 80 rounds. And then I clean it only because I don’t want to return a test gun to the manufacturer with a dirty barrel! If I’m going to hunt with that rifle, so long as it’s shooting acceptably well, I won’t clean it because I know the three shots I’m going to take to check zero on arrival in hunting camp will likely print a similar size group and have the same point of impact as the last group I fired back home.

Like barrel break-in procedures, barrel cleaning can be taken to extremes bordering on alchemy, and I’ve got no room here for either. Suffice to say there are dozens of excellent bore cleaning solvents and lubricants out there, and there are dos and don’ts. For one, clean from the breech end, and always use a bore guide. Use only brass bore brushes, never stainless steel, and never try to reverse the direction while the brush is in the barrel; always push them clear of the muzzle before reversing direction. As for cleaning rods, use the one-piece kind made of stainless steel or ones that are nylon coated.

To sum up, when it comes to a hunting rifle, I’m a minimalist regarding both breaking in a barrel and cleaning it. The typical hunting rifle is fired fewer than 200 rounds in a lifetime, and most of them are at targets.

I believe a barrel shoots best after 20-30 rounds have been put through it, and that’s usually all that’s needed to reach that gun’s potential. If it makes you feel better to venture afield with a clean barrel, by all means. As for me, if it’s shooting well at the range, I go huntin’ with a dirty barrel.

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