Curious how you were able to get the bullet in the case gauge originally and then it wouldn't come back out? Did you have to force it into the case gauge originally? If it went in easily to start how did it not come out easily?
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COAL using CBTO from Hornady OAL gauge significantly shorter than book COAL?
- Thread starter reformedcitykid
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It went in, I didn't have to force it. But there was enough resistance that it stuck when lightly pushing with the rod. I realized once I took the gauge out and mimicked the procedure while watching it that the resistance I was meeting was from the neck, not the lands
waspocrew
Well-Known Member
I usually start at 0.020" of the lands. Seems to work out fairly well for me.
For a hunting rifle I don't like to be in the lands as having a bullet stick can be a deal breaker. Also, there can be some variance with the Hornady tool so I start at .020 off. Plenty of data out there suggesting being in the lands is not necessary. Especially in a creedmoor with it's throat design.
I have a CTR in 6.5ManBun, I just load to 2.850 COAL which fits in the magazine and feeds fine.
Unless you have a wildly out of spec chamber, you're not going to get anywhere near the lands (with most bullets) with ammo that fits in the magazine. Which is fine, kissing the lands isn't necessary.
I load to the longest length that fits in the mag (and functions), and only use the Hornady tool to make sure that length will *not* jam into the lands.
Only bullet I tried that will actually jam the rifling was the 127LRX *if I loaded it to the absolute limit of the magazine.
Unless you have a wildly out of spec chamber, you're not going to get anywhere near the lands (with most bullets) with ammo that fits in the magazine. Which is fine, kissing the lands isn't necessary.
I load to the longest length that fits in the mag (and functions), and only use the Hornady tool to make sure that length will *not* jam into the lands.
Only bullet I tried that will actually jam the rifling was the 127LRX *if I loaded it to the absolute limit of the magazine.
Mikecr
Well-Known Member
Why the Hornady OAL tool?
To find touching COAL there is the simple split neck method, the cleaning rod method, bolt disassemble & sneak seat until the bolt handle drops. Then there is this Hornady tool, plagued with problem potentials, and forcing an averaging of readings..
A search here ('Hornady OAL') reveals a large trove of issues with that approach.
Why do folks fixate on a book value?
If you seat the bullets however you like and load develop with your choice, it makes little difference to velocities.
In contrast, It makes a difference to accuracy, which is beyond usefulness of reloading books, and a direct driver to ignore them.
You might think 'well the published loads are based on declared COAL', but you still don't know what the land relationship of that COAL was -from whomever pulled those loads out of their behind. You don't know what their accuracy, ES/SD, or neck sizing or tension was. You don't know about their barrel, chamber, or case sizing.
There really is zero basis to lock in on any one number from some book.
To find touching COAL there is the simple split neck method, the cleaning rod method, bolt disassemble & sneak seat until the bolt handle drops. Then there is this Hornady tool, plagued with problem potentials, and forcing an averaging of readings..
A search here ('Hornady OAL') reveals a large trove of issues with that approach.
Why do folks fixate on a book value?
If you seat the bullets however you like and load develop with your choice, it makes little difference to velocities.
In contrast, It makes a difference to accuracy, which is beyond usefulness of reloading books, and a direct driver to ignore them.
You might think 'well the published loads are based on declared COAL', but you still don't know what the land relationship of that COAL was -from whomever pulled those loads out of their behind. You don't know what their accuracy, ES/SD, or neck sizing or tension was. You don't know about their barrel, chamber, or case sizing.
There really is zero basis to lock in on any one number from some book.
I appreciate the info here, but I'm not fixating on a book value. I'm not trying to match the COAL or any values given in the book. But the cartridge a) looked much shorter than any 6.5 that I've loaded or shot and b) measured .3 shorter than the book value which raised flags as being alarmingly short. It's just a reference, in fact I'm trying to measure CBTO & find the lands specifically so I do not have to go off of given load values and can develop loads specific to my rifle.
