COAL measure with calibers.
- Thread starter NORZ
- Start date
PTG makes a bullet comparator that looks like a big nut the fits on a bolt. It has the different caliber holes in it and all you do is place it on top of the bullet then measure with your caliper from the base of the cartridge to the top of the comparator. Midway has them and the product numbers are. 365-474 and 746-974 It takes two to get all the calibers but most can get by with only one size. This is about the cheapest way to go and this one dies not tie up your caliper by having to mount something on them.
NORZ .......
Check this out http://www.larrywillis.com/OAL.html
and http://www.larrywillis.com/instructions2.html
This one tool works on ALL calibers. It's the easiest way to set your COAL accurately, back from the bullet ogive. It's also designed to measure the chamber clearance,at the shoulder) that YOUR handloads will have in YOUR particular chamber.
- Innovative
Check this out http://www.larrywillis.com/OAL.html
and http://www.larrywillis.com/instructions2.html
This one tool works on ALL calibers. It's the easiest way to set your COAL accurately, back from the bullet ogive. It's also designed to measure the chamber clearance,at the shoulder) that YOUR handloads will have in YOUR particular chamber.
- Innovative
kitsap said:
+1
chucksniper ........
You'll need to purchase every single item on that page to do what our new Digital Headspace Gauge does.
You can read about all the comparator features this gauge has in the Tech Tips section on our website WWW.LARRYWILLIS.COM
- Innovative
You'll need to purchase every single item on that page to do what our new Digital Headspace Gauge does.
You can read about all the comparator features this gauge has in the Tech Tips section on our website WWW.LARRYWILLIS.COM
- Innovative
Is it just me or is the term 'cartridge over all length',aka COAL) confusing?
I have been using the term 'length to ogive',LTO) to refer to the distance from the case head to the bullet's ogive. That's the metric I record as I develop loads for my rifles. As the OP, I too wanted a consistent cartridge length measurement what was more precise than just measuring from the case to the end of the bullet. Bullet tips vary so much......
On the other hand, I use 'overall cartridge length',OAL) for the measurement of the round from the case to the tip of the bullet. I keep that record only so I can 'compare' the length of my rounds to others using the same bullet, with the understanding that the range in that measurement,case to tip) varies a LOT! I have seen it around .007 or so on a regular basis with non-competition bullets. That much variation in LTO would be totally unacceptable in my load development.
Anyway, that's how I do things. <GG>
Obviously I use a bullet comparator also. I forget the brand, but it's red in color and has 'fittings' for specific calibers. I think the cost was very reasonable, but can't remember. I bought it several years ago!
I have been using the term 'length to ogive',LTO) to refer to the distance from the case head to the bullet's ogive. That's the metric I record as I develop loads for my rifles. As the OP, I too wanted a consistent cartridge length measurement what was more precise than just measuring from the case to the end of the bullet. Bullet tips vary so much......
On the other hand, I use 'overall cartridge length',OAL) for the measurement of the round from the case to the tip of the bullet. I keep that record only so I can 'compare' the length of my rounds to others using the same bullet, with the understanding that the range in that measurement,case to tip) varies a LOT! I have seen it around .007 or so on a regular basis with non-competition bullets. That much variation in LTO would be totally unacceptable in my load development.
Anyway, that's how I do things. <GG>
Obviously I use a bullet comparator also. I forget the brand, but it's red in color and has 'fittings' for specific calibers. I think the cost was very reasonable, but can't remember. I bought it several years ago!
I've never heard the term 'length to ogive',or LTO) even though it is actually more correct.
However, it's easier to get more shooters to understand how to best determine an accurate method for finding a consistent 'overall length',COL -or- OAL). It's best determined by measuring up to the bullet ogive rather than to the bullet tip.
- Innovative
However, it's easier to get more shooters to understand how to best determine an accurate method for finding a consistent 'overall length',COL -or- OAL). It's best determined by measuring up to the bullet ogive rather than to the bullet tip.
- Innovative
gambleone .......
OAL and COAL mean the exact same thing.
OAL = Over-all length
COAL = Cartridge Over-all Length
- Innovative
OAL and COAL mean the exact same thing.
OAL = Over-all length
COAL = Cartridge Over-all Length
- Innovative
gambleone
Silver $$ Contributor
Innovative,
My mistake; maybe I invented a new term?
I never use either oal or coal. but use the comparator instead. Still not sure if the comparator measures off the ogive. I have a 6mm from Sinclair & one from Hornady. The one from Hornady is smaller. Doesn't seem to matter as long as you use one or the other. Still, just a point of reference.
My mistake; maybe I invented a new term?
I never use either oal or coal. but use the comparator instead. Still not sure if the comparator measures off the ogive. I have a 6mm from Sinclair & one from Hornady. The one from Hornady is smaller. Doesn't seem to matter as long as you use one or the other. Still, just a point of reference.The way I understand it the comparators do measure off of the ogive, typically a much more reliable and consistent measurement. I use Hornady's comparators and headspace gauges, they were formerly called stoney point comparators.
In reality though, it doesn't really matter tool you use. As long as the measurements are consistent throughout your ammo you are good to go. As with all things in reloading, consitency is accuracy.
In reality though, it doesn't really matter tool you use. As long as the measurements are consistent throughout your ammo you are good to go. As with all things in reloading, consitency is accuracy.
There seems to be alot of misunderstanding about these terms. In another thread, someone was asking for COL data. COL=Cartridge Overall Length, meaning base to tip. There was a post that was way off, because it was an LTO measurement that included the length of the comparator too. For any meaningful data, it must be understood which system the person is using to measure. I personally call the LTO measurement that includes the length of the comparator the 'comparator' measurement.
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