Myth: Perfect Barrel

2-Oct-13 – 09:04 by ToddG

One of the most common myths I’ve heard repeated throughout the shooting world has been the importance of a perfect barrel. At matches, during law enforcement testing, and even around the water cooler with engineers at gun companies it seems like many people consider the barrel of a pistol as some kind of sacrosanct, fragile object needing extreme care to maintain pristine condition.

Then there is my approach:

WTS17barrel-at-53kThe barrel pictured here (left) is from my Springfield Custom Shop 9mm Warren edition 1911 at a little over 53,000 rounds. It’s seen a steady diet of mostly +p pressure, lead-free ammunition. The barrel has been cleaned about twenty times, so once every 2,500 rounds or so on average.

The rifling has been completely worn away from the first third of the bore. We’re not just talking about lead and carbon fouling. We’re not talking about some little scratch or imperfection. A sizable chunk of the barrel is now smoothbore.

So with such tremendous damage the gun must surely be inaccurate as heck, right?

Well, earlier this week, Bill Riehl of Blackfire Engineering tested the gun in a Ransom rest as part of a comprehensive (and scientific) examination of the pistol. Result? At thirty-five yards, a ten shot group of Federal match ammunition measured 2.04″! Riehl specifically tests at thirty-five yards because it better detects minor stability issues than the traditional 25yd most pistol shooters use. And while you can only extrapolate roughly, the 2.04″ group at 35yd suggests you’d probably see sub-1.5″ at 25yd… in a barrel missing a third of its rifling, in a gun that’s got well over 50,000 rounds through it.

I’m not suggesting you should purposely abuse your pistol barrels. Shooting higher pressure, higher velocity ammunition wears barrel faster. Shooting lead-free ammunition wears barrels faster. Failing to keep barrels free of firing residue wears them out faster. If you want your gun to be as accurate as possible for as long as possible, you should take good care of it.

But just like most modern service pistols themselves, the barrels in today’s better handguns are incredibly tough and capable of taking a lot more punishment than most people realize. So the next time someone tells you that it’s important to “break in” your pistol barrel, or that you have to clean it every 200 rounds, or that some imperfection in the bore will ruin it forever just remember you’re talking about a 10MOA pistol, not a quarter-MOA precision rifle.

Train hard & stay safe! ToddG

  1. 18 Responses to “Myth: Perfect Barrel”

  2. Todd: Excellent report, which raises the question of how much rifling is needed to keep acceptable accuracy. Half the bore? A third? A twist at the end? We might well be fooling ourselves about many firearms-related things that we “know to be true”–but aren’t.

    By SteveJ on Oct 2, 2013

  3. The plural of anecdote is not data, but this is a noteworthy anecdote. Thanks for posting.

    By Redchrome on Oct 2, 2013

  4. It makes me wonder what the bore looked like at the end of the P30 test!

    By john k on Oct 2, 2013

  5. Do you have any corresponding chrono data to see what impact the lack of rifling has on velocity?

    By JV on Oct 2, 2013

  6. Like John K, said…I am now curious as to what your P30 barrel looked like after your were through with the test.

    By Tim on Oct 2, 2013

  7. A 2″ J-frame jumps a bunch of freebore before encountering about an inch and a half of rifling, and they do okay in the mechanical accuracy department. You just need enough rifling to spin the bullet, and the bullet probably shouldn’t be yawing wildly when it engages it.

    Would you want all that freebore if you were trying for sub-MOA groups at three-digit ranges? Probably not. But this ain’t that. ;)

    By Tam on Oct 2, 2013

  8. Like John K, said…I am now curious as to what your P30 barrel looked like after your were through with the test.

    The lands and grooves were worn all smooth. :|

    By Tam on Oct 2, 2013

  9. Nevermind that the P30 probably started off with the lands and grooves worn all smooth… ;)

    By Redchrome on Oct 2, 2013

  10. *headdesk*

    By Tam on Oct 2, 2013

  11. Very interesting! I saw a colt .38 revolver. The whole middle portion of the bore was pitted, but the gentleman who owned it was capable of putting the contents of the cylinder into a silver dollar at 50 feet. He said the real important part was that there wasn’t any pitting at the muzzle or the crown. Otherwise accuracy only required a few inches of viable rifling.

    By John on Oct 2, 2013

  12. What does the worn out 1/3 of the barrel slug at?

    By Tyler on Oct 2, 2013

  13. The use of a 10 shot group makes the amateur statistician in me smile. 10 shot groups are ABSOLUTELY demonstrated to be a much better representation of what a gun will do than a 3-5 shot group. Given that it was in a rest anyway, that makes it more impressive.

    What would be interesting (and likely happened, I just haven’t seen it yet) is to test the velocity difference between the first round and last. Given that counter-boring a shotgun improves the performance, it wouldn’t surprise me if the erosion in Todd’s barrel had virtually no measurable effect on velocity.

    This is an impressive result.

    By dan-o on Oct 2, 2013

  14. This is the sort of thing that makes me smile when I see guys using brushes and solvent on the bore of their Glocks after shooting 1-200 rounds.

    By Chuck Haggard on Oct 3, 2013

  15. Chuck, especially when a short spray of creeping oil and two passes with a boresnake would make it cleaner than after the first of those 200 rounds.

    By Marc on Oct 4, 2013

  16. Good Opinion. There are certain disciplines that we can’t lump into a generalization though. Bullseye and PPC are two that come to mind. Ignoring barrel maintenance when shooting competitively at 50 yards WILL cost you points.

    By Craig on Oct 4, 2013

  17. While true for pistols, I may not be so with rifles, especially faster calibers.

    By 0987654321 on Oct 5, 2013

  18. I wonder how this result compares with barrel life seen by Chuck Taylor in his 300k+ test.

    By J on Oct 7, 2013

  19. Have a SVI 2011 that’s late 1990′s vintage with a bore that looks similar (I’m the fourth or fifth owner). Accuracy remains excellent and the same handloads produce near identical velocities in a new CZ TS.

    By Middle Man on Oct 7, 2013

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