Thread: Using comparator tool when seating projectiles.

Originally Posted by gqhoon

It’s quite common for rifles to have a CBTO tune window (node) of 0.006” (1.5mm). So using your example above, the 1mm variance either way equates to 0.008” between shortest and longest CBTO for a given projectile. So while you consider it to be tiny, it’s is enough to put you well out of a previously good performing node.

You really need to understand that the slightest difference in shape or profile of the ogive, will give a massive difference in CBTO measurement.

That’s 6 thou and a lot smaller than 1.5mm. Most people tune in the 3 - 5 thou window. 0.07mm - 0.12mm