Batteries always dead whenever you want to use it. Put a new battery in mine a couple weeks ago, and barely lasted a day. (Walmart Battery) I also have a caliper I bought at KMS Tools, looks to be a twin to the Mastercraft. I use a RCBS Stainless Dial type as well, no batteries on it to die.
Mastercraft Digital Caliper On Sale this week $14.99
- Thread starter Bigturk
- Start date
Brought a set several months ago as a backup. Seems OK for general use. However, it was gritty as hell. At $9.99 on sale I wasn't expecting much, but this one was disturbingly rough. But for $9.99, I figure what the heck. I diassembled the unit, and with a little solvent and toothbrushes cleaned all sorts of black crud off the gears. I was surprised just how much "stuff" was stuck to the insides. No wonder it was rough and gritty. I swear, the factory was paid to build these, but not to clean off their machining waste. After a 5-minute cleaning, it is super smooth. And works well enough for most reloading tasks.
Got two when they were 10 bucks each, one measure the test block accurately at 1.000", the other was .001 to .002 off. Exchange it for another that still drifts by .001. Wouldn't pay more than 10 bucks, nice for spare, don't use it for my primary.
The best caliper in the world is only accurate and repeatable within about .002 anyway. These calipers are as good as any other provided they're in good condition. I used a set at work for nearly 2 years and it kept passing calibration, where my set of starrett's did not. Take that for what it's worth.
Typically you'd measure a few items of known diameter. Could be gauge blocks, gauge pins, ground dowel pins, standards, or even just stuff that you've measured with a micrometer. They're kind of hard to adjust once they start to wear. Like I said before, though, if you're measuring anything where you need to be more precise than .003, you need a micrometer. Reloading rarely requires you to be more precise than .003".
calgarycanada
CGN Regular
- Location
- Calgary, Canada
So true, lot of folks don't understand limitations of equipment. If I wanna measure something down to 1thou or 1/10 of a thou I'll take out my micrometer that is at room temperature, put it in vise with soft jaws to make sure heat from my hands isn't effecting my reading. For general use crappy tire caliper a work just fine, I understand that reading is within a thou or two, I changed battery on mine after 2 years of use so not bad at all.
I don't have gauge blocks at home so I just use factory made jacketed bullets. I use a micrometer on them first to make sure they aren't really weird and then measure them with the calipers. If you keep an array of bullets around (.224, .308, .323, .430, .458, and .501 for me) you can try different diameters. I also have 2 micrometers so I can measure with both and make sure they agree.
I never measure bullet diameters with a caliper except to get a rough estimate. This includes barrel slugs, cast bullets, and jacketed ones. OAL doesn't matter down to a couple thou unless you're doing extreme precision long range shooting (even then some argue that it doesn't matter) but for bullet diameter, especially cast bullets, I want more precision.
