Barnes Bullet Seating Depth

AZ82New

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Ok, so I measured the seating depth on my 280AI.

I did this by using a fire formed case and painstakingly adjusting my Redding seating die in tiny increments with a 120 TTSX. I kept adjusting down until I could chamber the cartridge.

I did this twice. With two different bullets. Both measurements were very similar. I took more care the second time and ended up at 2.810. So that's the measurement I'm going with. Unless you guys have better advice.

So here is my question:

I measured the load I have been using with the 120 TTSX bullet using a Hornady bullet comparator. The measurements vary slightly, as do the bullets themselves if you measure them but the load roughly averages 2.668.

I hear all this stuff about seating the bullet "ten thousands from the lands" as a starting point…..I'm 142 thousands from the lands. 14 times that number. The groups are great though. The best was .447 center to center and the worst was .626 center to center. This is in decent wind. The bigger group was shooting off the bipod. The smaller was once I adjusted the scope and was using a Caldwell rest.

I don't even think I would be able to fit the cartridge into the magazine if I was ten thousands off.

Am I doing this right?
 

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I have found that the ttsx group much better when seated deep. They seem to like to jump to the lands. I don't know about your overall length though. At 2.66 the bullet is only like 1/8" out of the case?
 
Bullets definitely more than an 1/8 out if the case.

The COAL is 3.277 ish (varies a lot by bullet).

Using the comparator, it's 2.677….I just retested them and I misprinted the first time. So I am 133 thousands off the lands.
 
Maybe this will clear up what I mean:
 

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Sorry, wasn't thinking comparator, sounds like you have a good load...I've had to push some further than that from the lands to tighten them up
 
My buddy's 300Wby mag Mark V rifle shoots best with the Barnes bullets .250" off the rifling. Yup - a full quarter of an inch. It sounds like you've got things figured out pretty well for your rifle and the bullet you selected.
 
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