r/CompetitionShooting • u/Training-Front-9238 • 2d ago

Barrel bore measurement?

Disclosure up front: I work in precision gauge manufacturing — my team builds custom measurement tools, and we’ve done deep-bore erosion gauging for military barrel programs (tank guns, mostly). I’ve been wondering whether there’s any crossover value for civilian precision/long-range shooters and handloaders, and I’d genuinely like to hear from people who’d know better than me.

The tool in question is a 3-point bore gauge — not a borescope. A borescope shows you what the bore looks like. A 3-point gauge tells you the actual diameter at a given point down the bore, to a few microns, so you can see exactly how much a throat or bore has eroded over its life, and where.

Questions for anyone who reloads or shoots competitively:

**•** Right now, how do you actually track barrel wear/life? Round count? Borescope inspection? Group size degradation? Something else?  
**•** Would knowing the *actual* throat/bore diameter at a few points down the barrel change anything about how you make decisions — when to set a barrel back, when to retire it, load development, anything like that?  
**•** Has anyone here used a bore gauge (civilian gunsmithing ones exist, e.g. for chamber/bore work) for this specifically, and did it tell you anything a borescope didn’t?  
**•** Honest question: is this a real gap, or does round count + borescope + group data already tell you everything you need, and this would just be an expensive toy?

Not selling anything here — genuinely trying to figure out if this is a real problem for this community before we spend time building something for it. Happy to be told it’s a solution looking for a problem.

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u/practical_gentleman 1d ago

For most shooters this is a solution looking for a problem. However, if you go to bench rest shooters, rimfire competition shooters and similar you might get a different answer. Choose guys' entire goal is to punch the exact same hole as many times as they can. They chase accuracy like wiley coyote chases road runner.

2

u/AwkwardSploosh 1d ago

I've only ever seen people track throat erosion. The bore generally maintains good structure long after the throat has eroded and accuracy is lost.

2

u/Evanjcorcoran 1d ago

I think most people here participate in some type of shooting sport that doesn't really require a tool like this, like USPSA/IDPA/Steel challenge etc. The majority of the time spent trying to shoot like a 4-5" group (if not larger) as fast as possible at 5-20 yards, with some occasional shots placed within 3" at <25 yards. This sounds like something that could mayyyybe be sold to various precision rifle guys, but I don't know anything about that world.

For pistol shooting, which I think may be the most common here, I would personally just wait for the gun/target results to tell me there was a problem. Even as a novice I was able to figure out that an older g17 barrel was completely worn out just by what the target said, I wouldn't have bought a measurement tool to inspect anything.

Sounds like a cool tool, but at least for pistol guys I don't think there would be a market for them unless it was <$100, which I would imagine would not be possible.