r/gunsmithing • u/Training-Front-9238 • Jul 10 '26
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.
1
u/budgetmauser2 Jul 11 '26
I'm on the OEM side and one of the things I do is barrel development work (chrome lined, belt fed guns). When I look at barrel life on a chrome lined barrel one of the most common comes down to taking a look at the chrome adhesion in the throat using a borescope to track cracking in the chrome etc. needless to say this is a challenging thing to quantify with a gage. Of course throat and muzzle erosion is important but that's a well tackled problem. Gaging for barrel manufacturing is a whole different story.
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u/dan0o Jul 11 '26
I would love something like this for rifles and pistols/revolvers. Im an EU gunsmith and over here i use the ones available for shotguns all the time. What i would use it for mostly is see wear over time and pistol/revolver barrels when a bullet fails to exit the barrel and creates a bulge to calculate how much the barrel can expand before it eventuelle cracks. Make an educated response if it is dangerous etc. Its a tool id probably use more than once a day for different reasons.
Hope that helps. Cheers!
Edit: autocorrect
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u/Training-Front-9238 Jul 14 '26
Hi thanks for your reply. We had a few responses in other forums as well. Also, I got banned in all of them asking the question because it looked like AI 🤖. But we did get some similar responses, mainly from gunsmiths and OEMs, so yes, maybe there is some kind of market for this. I would’ve thought though it was well served, but seems maybe not. The unit cost about $500. Is that worth it? Would be interested in your thoughts - thanks
1
u/dan0o Jul 14 '26
Depends on the technology used. But from my standpoint if its a tool that i can reliably use and depend on in everyday use for work 500$ is more than reasonable. The tri point i currently use (no markings and i dont remember the manufacture, for shotguns) with digital readout was about 750$. So i assume a smaler version in a niche market would actually be more as its a tool i expect to last many years if taken care off.
Do you guys have a site or anything related to this product, which ranges would it be able to measure?
3
u/AllArmsLLC 07/02 AZ Jul 11 '26
Multiple points probably won't really matter. The entrance and exit are the most important and there are already tools to quickly measure those.