Measure off lands

[Bmoore0062]

So I have a hornady OAL Gauge and bullet comparator. I have measured and measured my 308 for 175 nosler RDF and I keep seeing variations off .01”. Anywhere from 2.149” - 2.247”

Should I try marking the bullets with a sharpie too?

Also, when is too much persure, to much pressure when pushing the projectile forward. I am obviously not slamming it forward and it’s not getting stuck in the barrel.

Do you all stop the second you feel the slightest resistance?

 

[Milo 2.5]

You need to do it the same each time regardless of pressure applied, but stopping when you first feel it is best. Also if a new chamber, you may have some ragged edges your fighting, if so, fire 10 rds and redo.
Not sure what your goal is, but it is just a number, and most likely you will fine tune your seat depth to your load. I'm from the camp that yes you need to know, but it is a guidleline, so therefore somewhat insignificant.

 

[Deleted member 10043]

It takes a little getting used to. In addition to the gray rod you need pressure on the red tube using the brass bolt before tightening. Also check the case periodically to make sure it has not come loose. Personally, I jam it up in there.

 

[Bmoore0062]

Thanks, I figured I am reading to far into it. So I got the most consistent ready by pushing the gray rod foward and having the projectile to far out to begin with. Then leave the gray rod loose and advance the red tube. Then this allows the projectile to push back to its proper seating depth. I plan to seat .03” off the lands.

 

[Deleted member 10043]

Like a boss!

 

[Sheldon N]

RDF have a really long sloped nose so in my experience they sort of slide into the lands rather than quickly hitting resistance.

Personally I'd just jam it all the way in firm so that it stuck hard, knock the bullet out with a cleaning rod, then measure. That's your "all the way jam" number, and touching the lands is probably 10-20 thou back from there. Test your seating depth in the range of another 20-30 back (25-40 off hard jam) and see what shoots best.

 

[palmettoman]

I take 5 measurements with each new bullet I'm trying out and use the average. Only takes a few minutes and I feel better about my seating depth.