Newbie Question - Jump/COAL

[sundog57]

I have been loading a couple of different weights of Barnes bullets.
Can I make the assumption that whereas the front end profile is pretty much the same for all bullets, that the ideal COAL measured with a comparator would be the same for a different weights - say of 150s and 165s or for 150s and 130s or am I likely to see a significant difference in group size with the same COAL with different weights.
Normally not a question as I would just go out and shoot a bunch, never a bad thing, but given that powder has now become yet another example of unobtainium, I am reluctant to use more than I have to.
I know that the correct answer is probably to pick one bullet weight that shoots well and use it for everything, but i have these bullets you see...
Thanks for your input

 

[cosmic]

You should not assume the ogive profile is the same for different weights, as the bullets were likely make on different assembly lines - best to check. The rifle will perform differently with different bullet weights, this is due to barrel harmonics, which generally trump bullet jump. All you can do is try - some rifles are more forgiving than others wrt bullet weight. However, I think its fair to say that a good bullet/load combo will show promise right out of the gate. No need to do elaborate tests for each weight - try groups of 5 with a mid range load of powder, same bullet jump.