Measuring to the lands

[Gene]

No matter which comparator or other device you use it will be nothing more than a approximate point where you hit the ogive. After you make the measurement, prepare a dummy case from the same rifle (no powder or primer) and seat the bullet to about .005" beyond the comparator measurement, gently close the bolt on the dummy, and remove it from the chamber. With a jewelers loupe, or magnifiner, find the faint marks made by bullet kissing the lands. Do this three times, average the results, and mark it down. From that point, with those same bullets, you will always know where to start either jumping or jamming your bullets.

 

[davkrat]

Not likely, it absolutely would... So from your perspective a 0.100" jump is the same as a 0.001" ... I guess a jump is a jump. I'm glad thats all I need to determine.

NOPE! Absolutely not. What I am saying is that the units of measurement on your calipers don't mean squat. If it's 3.025", 3.027", 6.3 cm or 1,927 widget widths.... Who cares? All that matters is the difference. If you measure your bullets to the lands at 1,927 widget widths and find through CBTO trials that loaded rounds at 1,922 widget widths (a jump of 5 widgets) is the most accurate than that's all the info you need for future set up of your reloading die with that bullet for that barrel measured by that particular caliper. The dummy round contacts the lands of your barrel while the caliper measures somewhere along the curve ahead of it. It should routinely and repetitively measure off the same point along that curve bullet to bullet of the same make/model. Others claim lot to lot differences but for a hunting gun I wouldn't be worried about being that picky.

In the end where you measure shouldn't matter as long as you are not measuring the tips which can be highly variable and easily damaged. That's the whole reason for the comparator rather than an OAL measurement with straight calipers.

It's all about the DELTA.

 

[FEENIX]

No matter which comparator or other device you use it will be nothing more than a approximate point where you hit the ogive.

Yep, that's why I commented ...

Sorry but I think you're still complicating it unnecessarily, each bullet design as noted by others will yield different results,

"WE", along with provided references, must be missing something in the explanation, IMO, it's very simple and everyone was basically saying the same thing to the OP.

 

[ohiohunter]

x2 Feenix. Early on in the thread you solved my dilemma with article you posted.

 

[FEENIX]

x2 Feenix. Early on in the thread you solved my dilemma with article you posted.

Copy that, cheers!