Coal/cbto

[JakeSCH]

Not at all the same thing. CBTO and COAL measurements are different and one can introduce error that the other won't in certain scenarios.

Lol if you read the previous threads. The guy who does COAL sets his die based on COAL then doesn't adjust it aka the exact same thing CBTO does.

I know the difference, but once i read that it made the thread funny.

 

[N2TRKYS]

Lol. I’m not trying to argue with you, I’m trying to help the OP and politely give what years of chasing consistency has taught me.

Please clarify your side of this without trying to run over me with the bus. How does an inconsistent BULLET base to ogive effect Cartidge Base to ogive?
If there is merit to it, I guarantee I will listen.

Lol. No, but I use that measurement to compare it to the overall length of the bullet. What I’ve found, is that that difference has been within the 0.002+/- variation that folks seem to accept under normal loading procedures.

 

[Clucknmoan]

Lol. No, but I use that measurement to compare it to the overall length of the bullet. What I’ve found, is that that difference has been within the 0.002+/- variation that folks seem to accept under normal loading procedures.

Roger. But what takes the most damage on a bullet that would show up as inconsitencies? Bullet tips or ogive? Ogives do not get damaged, they are what they are. Bullet tips get marred, bent, meplats aren’t the same. You have to admit that the tip is the week point of the entire loaded shell for inconsistencies. It just is.

 

[Brendan]

Lol if you read the previous threads. The guy who does COAL sets his die based on COAL then doesn't adjust it aka the exact same thing CBTO does.

I know the difference, but once i read that it made the thread funny.

First off, why would I go searching someones previous threads to try and understand them every time a post came up that sounded off the wall? And, I don't care what measurement you take, you don't even need to take one, if you set a die and don't adjust it, of course it's going to give you consistency round to round as long as you don't have issues with the rest of your process.

But, if you're measuring COAL of loaded rounds and using that as a comparison loaded round to loaded round, it can introduce error and you're much better off using CBTO for that measurement. How the whole thread started was that the OP was setting rounds to a specific COAL and wondering why his CBTO was varying...

 

[JakeSCH]

First off, why would I go searching someones previous threads to try and understand them every time a post came up that sounded off the wall? And, I don't care what measurement you take, you don't even need to take one, if you set a die and don't adjust it, of course it's going to give you consistency round to round as long as you don't have issues with the rest of your process.

But, if you're measuring COAL of loaded rounds and using that as a comparison loaded round to loaded round, it can introduce error and you're much better off using CBTO for that measurement. How the whole thread started was that the OP was setting rounds to a specific COAL and wondering why his CBTO was varying...

Lol wow you sound very frustrated. Earlier today i went to add my agreement on my importance in using CBTO over COAL and read a comment from N2TRKYS (this thread, 9:40 am)

I don’t move my seating die.

At that point I laughed and decided I did not need to add agreement because by not changing your seating die you are actually seating based on CBTO. So everyone here is seating based on CBTO whether they know it or not. Everyone is in agreement here, just using different terminology (right or wrong).

I noticed all the comments since this morning and figured N2TRKYS was trolling you guys. Hence my amusement.

 

[OXN939]

Lol wow you sound very frustrated. Earlier today i went to add my agreement on my importance in using CBTO over COAL and read a comment from N2TRKYS (this thread, 9:40 am)



At that point I laughed and decided I did not need to add agreement because by not changing your seating die you are actually seating based on CBTO. So everyone here is seating based on CBTO whether they know it or not. Everyone is in agreement here, just using different terminology (right or wrong).

I noticed all the comments since this morning and figured N2TRKYS was trolling you guys. Hence my amusement.

 

[briscoetab]

Lol wow you sound very frustrated. Earlier today i went to add my agreement on my importance in using CBTO over COAL and read a comment from N2TRKYS (this thread, 9:40 am)



At that point I laughed and decided I did not need to add agreement because by not changing your seating die you are actually seating based on CBTO. So everyone here is seating based on CBTO whether they know it or not. Everyone is in agreement here, just using different terminology (right or wrong).

I noticed all the comments since this morning and figured N2TRKYS was trolling you guys. Hence my amusement.

I thought perhaps he was trolling too but I don’t think so. On top of that it still not exactly the same. If you are checking measurements from bullet to bullet or every few bullets by measuring COAL you are not actually getting the true variance between lands and ogive which is what is important overall. I agree once you set a die CBTO should stay the same regardless if you are measuring CBTO or COAL but if something is wrong you may miss it if you are just measuring COAL since there is larger variations in it with some bullets.

I rarely have more than .001 difference in my measurements for CBTO but if I was using COAL on my SMK’s it would show up as .008 variance (the measurements I shared earlier) which would make me think something is wrong. Or if I was only getting .002 variance with those SMK’s by measuring COAL something would be wrong then because it should be .008.

Anyways I don’t think for most people it really matters. Probably doesn’t matter for me much but I do try to be pretty precise with some of my measurements, CBTO being one of them because I do shot pretty far but I only check every 5 to 10 bullets just to make sure nothing is wrong. Really that is what it comes down to, a troubleshooting measurement after you figure out where you want you die set. If the measurements start showing up as being different then usual you may have an issue, if they stay the same your good to go regardless if it is CBTO or COAL measurement.

 

[JakeSCH]

I thought perhaps he was trolling too but I don’t think so. On top of that it still not exactly the same. If you are checking measurements from bullet to bullet or every few bullets by measuring COAL you are not actually getting the true variance between lands and ogive which is what is important overall. I agree once you set a die CBTO should stay the same regardless if you are measuring CBTO or COAL but if something is wrong you may miss it if you are just measuring COAL since there is larger variations in it with some bullets.

I rarely have more than .001 difference in my measurements for CBTO but if I was using COAL on my SMK’s it would show up as .008 variance (the measurements I shared earlier) which would make me think something is wrong. Or if I was only getting .002 variance with those SMK’s by measuring COAL something would be wrong then because it should be .008.

Anyways I don’t think for most people it really matters. Probably doesn’t matter for me much but I do try to be pretty precise with some of my measurements, CBTO being one of them because I do shot pretty far but I only check every 5 to 10 bullets just to make sure nothing is wrong. Really that is what it comes down to, a troubleshooting measurement after you figure out where you want you die set. If the measurements start showing up as being different then usual you may have an issue, if they stay the same your good to go regardless if it is CBTO or COAL measurement.

100% agree. If i said they were the same, that is not what I meant. I just meant from the down stream consistency of CBTO should be the same assuming you have the same die setting / lever throw / pressure. A lot more can go wrong using COAL (especially batch to batch or if you are making adjustments in the middle of a batch) and I would never personally use COAL. Just a lot of those reasons were already said earlier in the thread and there was no reason to rehash them.

 

[briscoetab]

100% agree. If i said they were the same, that is not what I meant. I just meant from the down stream consistency of CBTO should be the same assuming you have the same die setting / lever throw / pressure. A lot more can go wrong using COAL (especially batch to batch or if you are making adjustments in the middle of a batch) and I would never personally use COAL. Just a lot of those reasons were already said earlier in the thread and there was no reason to rehash them.

No, I knew you were not saying they were the same, I probably worded that wrong. Think we are on the same page. Hopefully the op is too.

 

[Lawnboi]

I use a cleaning rod and the bullet I want to use. Very easy and accurate.

Havnt heard of that method till today. Interesting.
I’m still going to load off the ogive.

 

[tdhanses]

Havnt heard of that method till today. Interesting.
I’m still going to load off the ogive.

Really his method is no different then the Hornady oal tool, does the same thing.

 

[OXN939]

100% agree. If i said they were the same, that is not what I meant. I just meant from the down stream consistency of CBTO should be the same assuming you have the same die setting / lever throw / pressure. A lot more can go wrong using COAL (especially batch to batch or if you are making adjustments in the middle of a batch) and I would never personally use COAL. Just a lot of those reasons were already said earlier in the thread and there was no reason to rehash them.

Memes and jokes aside, I do think it's important to note that as long as you don't touch your loading die between rounds, you are actually loading based off of a consistent CBTO, even if the initial measurement to get that was taken by COAL.

 

[Clucknmoan]

Memes and jokes aside, I do think it's important to note that as long as you don't touch your loading die between rounds, you are actually loading based off of a consistent CBTO, even if the initial measurement to get that was taken by COAL.

True. Back to the OP’s original issue, if you haven’t touched your die between rounds and you are seeing inconsistencies in BTO, it’s usually inconsistent neck tension. Have seen compressed loads show variances in BTO as well.

 

[MeatBuck]

I have as consistent neck tension as a Sinclair expander mandrel and dry lube will allow.

 

[Cahunter805]

I have as consistent neck tension as a Sinclair expander mandrel and dry lube will allow.

Are you turning necks?

 

[Clucknmoan]

I have as consistent neck tension as a Sinclair expander mandrel and dry lube will allow.

That’s the perfect way to set tension. You can’t do any better.

Can you feel any difference in resistance as you are seating? Annealing necks or no? Can you feel your seating stem “catching” on the bullet after seating on the upstroke?

 

[MeatBuck]

There is some slop in the linkage on this Redding t7 and if I don’t bump the bottom out point a couple times I usually end up slightly long and have to run it in and bump it another time or two to get that 3.0805” down to a 3.0800”.
I shouldn’t have that problem when only measuring cbto however.

 

[MeatBuck]

Are you turning necks?

No. Have case neck sorting tool and concentricity gauge and don’t see a need from the readings I’m getting from those. Very little runout.
Had to turn the shell holder a tad to get em to come out straight when seating but that was easy enough.

 

[Clucknmoan]

There is some slop in the linkage on this Redding t7 and if I don’t bump the bottom out point a couple times I usually end up slightly long and have to run it in and bump it another time or two to get that 3.0805” down to a 3.0800”.
I shouldn’t have that problem when only measuring cbto however.

Not sure what you mean by won’t effect BTO. The BTO measurement is taken below where the seating stem contacts, so by bottoming it out it should effect BTO. Or am I misunderstanding what you are saying.
It really isn’t a bad idea to bottom out a couple times anyway. If I am getting bad runout, I will bottom the press out, then rotate the case 1/3 or 1/2 turn or so and stroke it again. Sometimes it helps with runout if you have a case or die that sits wonky in the press.

 

[MeatBuck]

That’s the perfect way to set tension. You can’t do any better.

Can you feel any difference in resistance as you are seating? Annealing necks or no? Can you feel your seating stem “catching” on the bullet after seating on the upstroke?

No difference in force needed to seat. No annealing as I haven’t even gotten into once fired state with this brass yet. And yes it barely has a grip on the bullet as I’m coming back down. That feeling is the seater contacting the bullet and holding slightly above the ogive from where it forces the bullet into the neck correct? Otherwise the bullet nose would be bottoming out first and not allowing for the slight grip of the stem on the bullet? Or why do u ask?