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Caliper case holders?

This is a shot in the dark, but google turned up nothing so thought maybe the experts here knew something I didn't.. I'm having a really hard time being consistent with my calipers measuring case length and bullet OAL. Between not always holding the case perfectly straight, and not always perfectly aligning the projectile tip to the caliper arm, I'm finding myself measuring multiple times and coming up with measurements as much as 0.0050 apart.

With my headspace gauge, that measurement is always dead-on, because the cartridge is always consistently held. Is there a simliar "holder" out there that clamps onto caliper arms for empty brass and assembled ammo? Even just something that makes the caliper arms wider, giving me more space to hold the bottom of my cartridge flat against them would do.
 
This is a shot in the dark, but google turned up nothing so thought maybe the experts here knew something I didn't.. I'm having a really hard time being consistent with my calipers measuring case length and bullet OAL. Between not always holding the case perfectly straight, and not always perfectly aligning the projectile tip to the caliper arm, I'm finding myself measuring multiple times and coming up with measurements as much as 0.0050 apart.

With my headspace gauge, that measurement is always dead-on, because the cartridge is always consistently held. Is there a simliar "holder" out there that clamps onto caliper arms for empty brass and assembled ammo? Even just something that makes the caliper arms wider, giving me more space to hold the bottom of my cartridge flat against them would do.
What nettle said. Tommy Mc
 
This is a shot in the dark, but google turned up nothing so thought maybe the experts here knew something I didn't.. I'm having a really hard time being consistent with my calipers measuring case length and bullet OAL. Between not always holding the case perfectly straight, and not always perfectly aligning the projectile tip to the caliper arm, I'm finding myself measuring multiple times and coming up with measurements as much as 0.0050 apart.

With my headspace gauge, that measurement is always dead-on, because the cartridge is always consistently held. Is there a simliar "holder" out there that clamps onto caliper arms for empty brass and assembled ammo? Even just something that makes the caliper arms wider, giving me more space to hold the bottom of my cartridge flat against them would do.
I've never encountered a micrometer big enough to do OAL.. a
Calipers are a shortcut verses micrometers. You will never get the "feel" from calipers that you can get from a micrometer.
I've never used a micrometer, any particular one you'd recommend?
 
Calipers are a shortcut verses micrometers. You will never get the "feel" from calipers that you can get from a micrometer.
Are you using a mic to measure COAL?

I am taking the OP's question as: I am measuring cartridge overall length and case length and am having difficulties holding both ends square to the caliper jaws. Is there a device that clamps on to the jaw as an aid for this?

If that's the question, then yes, there are aids for that., but they measure at a different datum. I will add that you may be better off in measuring your base to bullet ogive instead of the cartridge overall length, unless you're loading short for a magazine.

It sounds like you have a headspace comparator and there are also bullet comparators that measure similarly to your headspace gauge to measure (at least close) from case base to bullet ogive. It's a relative distance that can be duplicated.

If this is not correct, please pardon the interruption......
 
Are you using a mic to measure COAL?

I am taking the OP's question as: I am measuring cartridge overall length and case length and am having difficulties holding both ends square to the caliper jaws. Is there a device that clamps on to the jaw as an aid for this?

If that's the question, then yes, there are aids for that., but they measure at a different datum. I will add that you may be better off in measuring your base to bullet ogive instead of the cartridge overall length, unless you're loading short for a magazine.

It sounds like you have a headspace comparator and there are also bullet comparators that measure similarly to your headspace gauge to measure (at least close) from case base to bullet ogive. It's a relative distance that can be duplicated.

If this is not correct, please pardon the interruption......
You're right, I'm measuring an assembled round, from the primed base to the very tip of my hornady ELD projectile. The little red polymer tip is giving me the most headache, as its tiny and slips constantly. Similar issue measuring my trimmed cases -- they wobble just enough to throw me off.

If I were to measure ogive, what would I reference? Just an existing factory round? Or would I use my OAL gauge to find the lands in my rifle and measure ogive on that as my baseline reference number?
 
Clamp the fixed blade of your caliper in a drill press vise, then zero the caliper. The vise will give you a bigger platform for the base of the brass. As mentioned above, rotate the case.
 
You're right, I'm measuring an assembled round, from the primed base to the very tip of my hornady ELD projectile. The little red polymer tip is giving me the most headache, as its tiny and slips constantly. Similar issue measuring my trimmed cases -- they wobble just enough to throw me off.

If I were to measure ogive, what would I reference? Just an existing factory round? Or would I use my OAL gauge to find the lands in my rifle and measure ogive on that as my baseline reference number?
is this for a bolt gun?
 
You can practice with calipers all you want. If you go into a precision machine shop using CNC machines they won't be using calipers, (at least I hope they are not on my gun parts), they will be using micrometers. I have both micrometers and calipers. Calipers are OK for rough stuff like case length and COAL. For the more precise stuff like neck thickness or bullet diameters I use mics.
 
What works for me is rotating the case with my fingers while the calipers are closing in. This allows the case to "settle" in the caliper jaws under light pressure while providing repeatable measurements.
^^^^^^ THIS.
 
I found that the Hornady anvil base as linked to above helps with getting a consistent feel and measurement.
I found the chances of the Hornady anvil base being square is about 50/50 at the very best. I’ve seen far too many of them that aren’t square to mess with that route again.
Dave
 
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I found the chances of the Hornady anvil base being square is about 50/50 at the very best. I’ve seen far too many of them that aren’t square to mess with that route again.
Dave
I found out you sure don’t want to measure something between the anvil and the side of the bullet comparator or headspace gauge, this will give false readings not being centered on the calipers.
 

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