Comparator reloading information

[AGGRO]

What is your go to?

[tabascoz28]

What do you mean, I thought a comparator is used to group your ammo after it's made so that they are all the same length and will most likely have the same POI. And the other uses to make sure that you're around that come out measures at the predetermined ogive.

[AGGRO]

What do you mean, I thought a comparator is used to group your ammo after it's made so that they are all the same length and will most likely have the same POI. And the other uses to make sure that you're around that come out measures at the predetermined ogive.

Looking for some charts that have all cartridge overall length, to shoulder, setback, etc. without looking up each single ogive using the proper bushing and caliper. This tool (comparator) is new to me and looking for all information available. Been reloading for a long time but this is something new to me. Mostly interested in those that use this for the AR, specifically 6.5 Grendel and using copper. Also using an analog caliper.

[damndave]

The comparator is used to measure the ogive to the base of the case. Every rifle is different. You need a headspace gauge to measure where the ogive touches the lands. Then subtract how much of a jump you want when loading.

COAL is not a good way to measure your loads as the tips of bullets vary quite a bit. Measuring ogive to base will always give you a consistent reading.

[pacrat]

The comparator is used to measure the ogive to the base of the case. Every rifle is different. You need a headspace gauge to measure where the ogive touches the lands. Then subtract how much of a jump you want when loading.

COAL is not a good way to measure your loads as the tips of bullets vary quite a bit. Measuring ogive to base will always give you a consistent reading.

[tabascoz28]

You might have to hand do it all the time. Different lots have different measurements, with the exception of the most expensive tips for match. I guess that's why some people buy the same lot and in large quantities so they don't have to measure again, after the initial spot check of course.

[AGGRO]

I ordered some more reloading equipment so I can measure base to ogive. What I have found with the dies I have is some of this "free brass" I got is much shorter from base to shoulder. Also ordering a digital caliper I can reset with the anvil base attached.

[fguffey]

I use comparators, believe it or not the comparator works when comparing. The Hornady/Sinclair tool that is used with a dial indicator is a comparator; it does not match SAAMI specifications.

I find the best use for a comparator is measure before and again after. Example; measure the length of a case from the datum to the case head and then fire. After firing measure the same case from the datum to the case head, after measuring the fired case compare the two lengths.

The Hornady gage was first introduced as a head space gage. And then I told them the case did not have head space, and that locked them up. Years later someone started labeling the Hornady/Sinclair tool as a comparator. And then there had to be a reason, the reason the Hornady/Sinclair tool never agreed with any specifications was caused by the radius at what they called a datum. All they had to do was zero the tool or take lessons from L.E. Wilson on making tools with datums with a radius.

F. Guffey

[fguffey]

The next wonder tool was the digital head space tool, no chamber involved just a case so the tool could measure the length of a case from a datum to the case head. The digital head space gage was a Dial Indicator Stand but who knew? They were all reloaders.

And then there was the 3 legged milk stool, I had a good laugh.

F. Guffey

[AGGRO]

The next wonder tool was the digital head space tool, no chamber involved just a case so the tool could measure the length of a case from a datum to the case head. The digital head space gage was a Dial Indicator Stand but who knew? They were all reloaders.

And then there was the 3 legged milk stool, I had a good laugh.

F. Guffey

Good morning Guffey!!

[nedro]

I use comparators, believe it or not the comparator works when comparing. The Hornady/Sinclair tool that is used with a dial indicator is a comparator; it does not match SAAMI specifications.

I find the best use for a comparator is measure before and again after. Example; measure the length of a case from the datum to the case head and then fire. After firing measure the same case from the datum to the case head, after measuring the fired case compare the two lengths.

The Hornady gage was first introduced as a head space gage. And then I told them the case did not have head space, and that locked them up. Years later someone started labeling the Hornady/Sinclair tool as a comparator. And then there had to be a reason, the reason the Hornady/Sinclair tool never agreed with any specifications was caused by the radius at what they called a datum. All they had to do was zero the tool or take lessons from L.E. Wilson on making tools with datums with a radius.

F. Guffey

Guffey, I'm an ignorant, amateur reloader.
What does it matter what your cases expand to if your chamber is good?
If it's new brass, it will fire form, which to me (ignorant amateur) would be my starting point, not before (unless you are simply adding that info into your records for, I don't know).

From there, I bump back the shoulder 2 or 3 thousands. You can use the comparator to measure the shoulder for consistency of your press I suppose. And once you establish your jump, the comparator is pretty damned close at measuring your bullet depth and COAL consistency. Not tip to base, ogive to base.

It's a tool. A tool that you can adapt to any measuring you want to do given its mechanical configuration.
The idea of measuring your rounds by its mechanical fit, rather than OAL with inconsistent tips is a good one. a comparator is a good place to start and gives you a platform to go deeper into the rabbit hole of reloading. From an Amateur's point of view.

If there is a better way, please teach me.
Thanks.

[fguffey]

Good morning Guffey!!

Thank you.

In the beginning it was a matter of transferring, in my opinion the transfer method eliminated tools , I do understand there are companies that sells tools for a living. Back then I would transfer measurements from the chamber to the seating die.

I thought there was an advantage to transferring; when transferring measurements from the chamber to the seating die the reloader did not find it necessary to wake to a new morning 'every morning'.

I have never been a 'seat your bullets into the lands' fan. I have always thought the reloader should be able to determine where they were.

F. Guffey

[AGGRO]

Got my digital caliper today just waiting on the rest of the parts. This is a perfect hobby for a pandemic. If you have supplies that is.

[nedro]

Got my digital caliper today just waiting on the rest of the parts. This is a perfect hobby for a pandemic. If you have supplies that is.

Which one did you get?

And Mr Guffey. I was truly serious about wanting to learn.
But the only thing I got out of your cleverly pontificated thought was that, although you can start a fire by waiting for lightning to strike a dry shrub, I'll still choose the lighter I brought with me as long as it works. And will use my fire stick and block when the lighter fails.

But of course, with all due respect to our Mr. Guffey; if all else fails, I will fall back to the lightning method. Unless of course, God is now somehow a tool maker, in it for profit.

[AGGRO]

Which one did you get?

And Mr Guffey. I was truly serious about wanting to learn.
But the only thing I got out of your cleverly pontificated thought was that, although you can start a fire by waiting for lightning to strike a dry shrub, I'll still choose the lighter I brought with me as long as it works. And will use my fire stick and block when the lighter fails.

But of course, with all due respect to our Mr. Guffey; if all else fails, I will fall back to the lightning method. Unless of course, God is now somehow a tool maker, in it for profit.

IGaging Origin. Looks like one of the go to for most serious reloaders using it for dies. Easy to zero with a die in place. Haven't had a chance to use it yet.