COL

[George Foster]

I would like to ask if say I am using Sierra 243 bullets in either a 243 or 6mm would bullets of different weights with the same ogives would give the best accuracy with the same COL? If I am shooting a 6mm and using a 2.860COL (Best accuracy) for the 75HP would a 80SPBT and a 85HPBT (They all have the same ogives) give the best accuracy after you found the best powder charge for each bullet give the best accuracy with a 2.860COL also?

 

[jcampbellsmith]

No.

 

[George Foster]

No.

Why?

 

[3dogs]

Projectiles of different bearing lengths will produce different pressures. You
will have to work up a load and test
Jim

 

[K22]

In my rifles, the Sierra 80SBT and 85BTHP have significantly different max COL's, the 85BTHP having the shortest so I'm don't think they have the same ogives or even close.

In my experience each bullet and rifle combination for the most party have different optimum COL's but not necessarily. The only way to know is to test for each combo. This is not a 'one size fits all situation' in my experience.

 

[M-61]

Measure base to ogive on the same box of bullets. Some makes are better than others meaning close to the same measurement. Hornady #3010 was the worst I have ever run across so far.Never mind getting to COAL.

 

[George Foster]

Thank You for your thoughtful replies. According to a Sierra tech all three bullets have the same ogives, he said in theory it might work but he and I both feel it is unlikely. I have shot all three bullets for 45+ years but this is something I got thinking about and was curious. I think when I can I will try it and see what I find. As I said I already have good loads for all three bullets in the 6mm and 243 also but I am always willing to try something new.

 

[Rsadams]

You as stated will need to work up a load for each one if you want maximum accuracy... Changing almost anything will effect something...

 

[Dusty Stevens]

They dont even have the same ojive in the same box much less off a different line