CBTO tolerances?

[ravot22]

How much difference in your reloaded rounds do you tolerate in reference to CBTO?

Does each bullet measure the same when you're done or are you tolerating a difference? Just curious how some serious reloadeders handle subtle differences in CBTO.

 

[EricL]

I apologize in advance for my ignorance but I ges I have never run across the abbreviation CBTO... what are you referring to?

 

[WAMBO]

Cartridge base to ogive would be my guess, I try to keep it to +/- .001".

 

[EricL]

O ok that makes sense, I would say +1 to +/- .001.

 

[FEENIX]

I try to keep it to +/- .001".

Same here!

 

[Canadian Bushman]

Cartridge base to ogive would be my guess, I try to keep it to +/- .001".

Same here

 

[AaronEdwardJames]

With Redding comp seating die you could get it to zero tolerance if your were guna go to the extra effort of sorting the bullets before hand if not and I've only loaded with lapua scenar 300 grains and out of 500 or so they were never more that .001 in whole batches so yeah +/- . 001 would be grand

 

[ohiohunter]

With Redding comp seating die you could get it to zero tolerance if your were guna go to the extra effort of sorting the bullets before hand if not and I've only loaded with lapua scenar 300 grains and out of 500 or so they were never more that .001 in whole batches so yeah +/- . 001 would be grand

I haven't experienced any of this, though I haven't compared basic dies to comp dies. What I have found is varying neck tensions will throw your CBTO off like crazy, and that is using a redding comp seater.

Your margin of error on seating depth will depend on your bullet and of course your rifle's preference. With a heavy stiff accurate tube and berger hybrids I could load with a variance of +/- 0.0025 (5thou window) and never tell the difference at 600yds, maybe even at 1k (but I haven't shot that line in a while). The hybrids are very forgiving when it comes to jump. A bullet w/ a more obtuse ogive may not be as forgiving.

When you have nice consistent neck tension you can seat like a well oiled machine, sometimes I'll only measure every few.

Another thing I take into consideration is the resistance to seat a bullet. If it is noticeably hard I will pull that round and use it for a fowler. This "feel" is far easier on an arbor press, but I think I manage my chucker rather well. There are now arbor presses with a pressure gauge, an old timer told me that was too much BS. Said if you can't cull your loads by feel (on an arbor) you're doing something wrong.