BTO Measurement

[crouch41]

OK guys, I must be stupid or something, but I can't understand whay the BTO would not be the same for every bullet when the bullet is seated on the lands. The distance from the bolt face to the lands is fixed and will not change. It seems that regardless of where the ogive is on the bullet, when the bullet is pushed fwd til it touches the lands, you are measuring the distance from the bolt face,or case head) to the lands, and that measurement will be the same as the BTO. I know from experience that the measurement varies, I just can't figure out why. Is there somebody out there that can explain.

 

[Cheechako]

crouch

If BTO means Base To Ogive, then the reason the measurement may vary from bullet to bullet is that not all ogives are the same. They damn well better be for all bullets of a particular lot but may not be when comparing brand A with brand B. A bullet with a 12 ogive seated in a 2 degree throat may not be the same as a bullet with an 10 ogive. The difference should be very small, but a difference none-the-less. If you're getting different measurements with bullets from the same lot, either your bullets are no good or you're not measuring right.

Now, if BTO means something else, then Never Mind!

Ray