Bullet eating variation

[mzvarner]

Using and RCBS JR2 press with standard RCBS 308 win full length re-sizing die and standard seating die. I am seating 178gr amax for a Rem 700 SPS. I am seating to 2.810 with tolerance + or - .001. I measure each round after seating and I am getting variations between 2.810- 2.816. Is this something to be concerned with? is 5/1000 of an inch much to worry about? why am I getting such variation? All brass is trimmed to the same length, bullets should be all the same length, seater die adjustments dont change (until they need to be pushed closer to 2.810). what gives?

lol just saw the title mistake...

 

[Red_SC]

Bullets aren't perfectly consistent, particularly at the tip. The distance between the base of the case and the point of the bullet that touches the seating stem will be consistent; the distance between that point on the bullet and the tip can vary a little without issue as long as the long ones dont drag in the magazine. The dimension that really matters is from the case head to the point at the base of the bullet ogive that touches the barrel throat first.

Edited to add: this is assuming you don't have a highly compressed load. It can be a sign that the powder is pushing the bullet back out.

 

[wtopace]

Try measuring the ogive of the bullet instead of the tip. The ogive measurement should be much more consistent, it doesn't really matter what you use, but you need a diameter that won't slide all the way down the bullet. The tips get damaged and squashed during handling, packing, shipping, loading, etc... Personally, I think the hornady set is very nice for the money.

Hornady Lock-N-Load Bullet Comparator Complete Set 14 Inserts

 

[mzvarner]

Edited to add: this is assuming you don't have a highly compressed load. It can be a sign that the powder is pushing the bullet back out.

I am using 43.5 gr of 4064 in twice fired Hornady match brass. It comes just up to the base of the neck.. I was looking at it earlier as being quite full, but IDK if its so full that it would push a bullet it...

I would love to get the Hornady set but i am reloading on a college/ part time work budget...

 

[gigamortis]

It depends on how much flex in in your press frame. I use a Lee Classic Cast press that is cast iron and my OAL variations are minimal as compared to when I was using an aluminum frame press.

 

[gac700]

The Hornady tool with that measures the ogive will help. Take you die apart and make sure it is clean. Double check the seater and clean it with a q-tip prior to loading a batch of rounds.