barrel micrometer
- Thread starter peterdobson
- Start date
I think you would be better off with a set of bore gauges in 10 thou graduations... that would handle the bore...
how you are going to measure the grooves?
Why is another question?
I would suggest contacting a barrel maker, telling them what you actually want to do and see what they recommend.
how you are going to measure the grooves?
Why is another question?
I would suggest contacting a barrel maker, telling them what you actually want to do and see what they recommend.
Provide better information.
What exactly, are you trying to measure, to what end? And how accurately?
Starrett, Mitutoyo, and all the other decent quality measuring tool makers, have catalogs that approach the size of small city phone books, with variations on size shape and accuracy that will make your head spin.
Unless you can actually define what you are trying to accomplish, asking for a universal tool to do all things is pretty much just wasting your time.
MIRAMICHIER
CGN frequent flyer
- Location
- Miramichi,Nb
Hey Peter check out Starrett No.700 series / .200-2" / accuracy .0002"
If you or your gunsmith has a good selection of reamer pilots you can use those to measure. They are in .0002" (two tenths) increments. They can be mounted on a 6" piece of 1/4" drill rod. De-grease the rod and use scotch tape to retain the bushings. This will give you bore size not groove size.
Pete
Pete
Hi Peter
If this isn't a quality, precision barrel trust the gunsmith and move on.
For a quality, precision barrel the game changes. Was it air gauged and does he mean the lands or the grooves? If he was setting up for chambering and noticed an oversize immediately, he would likely be talking about the lands. This does not necessarily mean the grove diameter, or main bore diameter, is too large. Who is the barrel manufacturer and was it air gauged.
I have learned enough to know that there are several methods to make a quality barrel and many reasons for an error and that no manufacturers are prefect.
If this barrel was supposed to be air gauged, you need to verify the findings and if verified, you really should let the manufacturer know of the problem.
For land diameter checks, you can simply install reamer pilot bushings on a "range rod" to find the diameter. Let me know if you want to borrow some.
Rob
If this isn't a quality, precision barrel trust the gunsmith and move on.
For a quality, precision barrel the game changes. Was it air gauged and does he mean the lands or the grooves? If he was setting up for chambering and noticed an oversize immediately, he would likely be talking about the lands. This does not necessarily mean the grove diameter, or main bore diameter, is too large. Who is the barrel manufacturer and was it air gauged.
I have learned enough to know that there are several methods to make a quality barrel and many reasons for an error and that no manufacturers are prefect.
If this barrel was supposed to be air gauged, you need to verify the findings and if verified, you really should let the manufacturer know of the problem.
For land diameter checks, you can simply install reamer pilot bushings on a "range rod" to find the diameter. Let me know if you want to borrow some.
Rob
slug it with soft lead, cheaper and faster then waiting for an expensive tool that your only going to use once arrive in the mail.
If it's over sized it may just shoot flat based bullets like a hot damn, boat tails not so much, regardless of what gauges and bore scopes say you're never going to know how it's going to shoot until the chamber is cut and it's threaded to an action. If this is the first time your "gunsmith" has seen a variation in bore or groove diameter it's a good time to get a new "gunsmith"
If it's over sized it may just shoot flat based bullets like a hot damn, boat tails not so much, regardless of what gauges and bore scopes say you're never going to know how it's going to shoot until the chamber is cut and it's threaded to an action. If this is the first time your "gunsmith" has seen a variation in bore or groove diameter it's a good time to get a new "gunsmith"
Really?
Any real reason to spend thousands of dollars on actual working and capable measuring equipment, or would this be a really good time to suggest just using it for a tomato stake and spending the money on a replacement barrel?
In all honesty, I would really have expected the Gunsmith to actually quantify the 'oversize'. And be able to come up with a better plan than to leave you swinging in the breeze looking for measuring tools (good ones are NOT cheap!) to measure what should either work or won't.
Slug that barrel at each end and through the middle and measure up the slugs for groove diameter with a quality vernier micrometer.
This will get you the info you need. Cerrosafe will also give the info, but the "window" of exact measurement
is fairly small, time-wise. Dave.
This will get you the info you need. Cerrosafe will also give the info, but the "window" of exact measurement
is fairly small, time-wise. Dave.
fingers284
CGN Ultra frequent flyer
- Location
- Alberta Cowboy Ranges
what I suspect the problem is here is that the gunsmith has a "solid pilot reamer" and it is of a smaller dia than the bore so he is afraid of "chatter" happening when chambering...a removable pilot reamer with a "custom fit" pilot bushing will probably end the problem.
I suspect same, but the OP has been less than really helpful with information. No real info about what the actual problem is, except that the gunsmith says it's oversize, when in order to actually provide anything really useful for an answer, a LOT more information would be required.
End of day he could have been shipped a .45 cal barrel instead of the .30 cal one he ordered. That would also fit his description. As would the thread not screwing in to the receiver.
