Checking neck wall thickness?
- Thread starter DRNewcomb
- Start date
Yeah. Some way I can gage the neck thickness before seating the bullet, to see if the neck needs to be re-turned. I was kind of wondering if there was any sort of feeler gauge that would do that. Other than your method, I can only think of sticking each one back on the neck turner, just in case, or using a tubing micrometer. Since I don't own a tubing micrometer I'll have to troll the pawn shops to see if I can pick one up.
These are on sale now at Sinclair:
http://www.sinclairintl.com/reloadi...meters/digital-thickness-gauge-prod36561.aspx
Pretty decent tool for the money.
Ken
http://www.sinclairintl.com/reloadi...meters/digital-thickness-gauge-prod36561.aspx
Pretty decent tool for the money.
Ken
The RCBS "Case Master" works too. It's not cheap at nearly a hundred bucks, but it does several different types of measurement including neck wall thickness using a dial indicator.
http://ads.midwayusa.com/product/31...3eZtg-la8TBjb8JTJTcUDccNT2JxTcqCSKhoCLUHw_wcB
http://ads.midwayusa.com/product/31...3eZtg-la8TBjb8JTJTcUDccNT2JxTcqCSKhoCLUHw_wcB
Jeepers! I have one of those. Never thought to use it to measure neck thickness.
Generally speaking, dials and dial calipers are not used to measure wall thickness, the reason is they are really only accurate to the 1 thousands and so if your neck is 12 to 15 thousands, there is really not much resolution. This is the reason why micrometers which are accurate to the ten thousands are used to measure neck wall thickness. About the only time a dial like the RCBS “Case Master” is used is to sort and cull cases i.e. figure out which are the ones which are way off.
You on the other hand is trying to see how consistent your necks which have already been turned are, so that is likely the wrong tool. Of course, if you don’t care not being able to figure out ½ thousand difference, a dial-based like tool like the RCBS will do, but if you don’t care about that degree of change, why think about re-turning your necks? Not giving you a hard time, just pointing this out.
You on the other hand is trying to see how consistent your necks which have already been turned are, so that is likely the wrong tool. Of course, if you don’t care not being able to figure out ½ thousand difference, a dial-based like tool like the RCBS will do, but if you don’t care about that degree of change, why think about re-turning your necks? Not giving you a hard time, just pointing this out.
Shynloco
You can lead a horse to water, but ........
Note the optimum word is "good." I thought I had "good" tools in Starrett Calipers and Mitutoyo Ball Mics. But recently in a similar topic discussing this very issue, I discovered my tools were marginal and on the lower end the of "precise" scale. In other words, it appears that based upon the comments of established competitors who chimed in, get your wallet out if you want to be serious about "precision" measurements that lead to better accuracy. Another poster above mentioned (and provided a link) the Sinclair digital tube mic that I just ordered in order to get to that .0001 measurement. $229 is still cheaper than the $600 digital micrometers competitors use. And I might note, many other factors such as how uniformly and evenly are you "micing" a case to determine how close each of the wall thicknesses are on your casings. Just food for thought. Remember, this stuff ain't cheap and you get what you pay for.
Alex
The time factor. I was looking for a quick and easy way to gauge if necks needed turning without chucking them in the lathe.
Go to the Long Island Indicator website. You'll find the facts about what is best, good, and cheap. The Mitutoyo ball mic is among the best made.
www.longislandindicator.com
Brians356
Silver $$ Contributor
If you just want to calculate, as you say, the average wall thickness, or want to know if the loaded neck OD is small enough to chamber, measuring a loaded round's OD with a good 1" outside micrometer with .0001" scale will work fine.
But that tells you nothing about neck wall thickness consistency, which (other than fitting necks to a tight chamber) is the only reason someone would bother to neck turn.
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You're missing the fact that none of the neck turning devices have a setting for .0125", for example. In other words, you can't just dial in the desired thickness. You need to sneak up on the cut, usually by turning a knob of some sort, until the cutter just touches the neck which you've already measured with a micrometer. Then, if the adjustment knob is calibrated, it's an easy job to turn it the desired amount. Still, you gotta' check a test piece or two to be sure you have the neck turning lathe set to the desired depth of cut.
Bottom line: You need a tool, usually a ball type micrometer, to measure the neck thickness before and after turning.
I don't know if its accurate but it looks like it is. I use the Forster concentrically fixture with the pilot from the trimming tool. I zero the dial indicator on the pilot then slide the piece of brass on and rotate it. I think its close enough for a old guy like me. I tried tubing mics but struggle with them, to easy get out of square.
Look into the Redding neck thickness tool. I have had mine for around 8 years and love it. Easy to use, but can't remember the cost.
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