Was getting very large variances when loading up some of the 69 smk I have been asking questions on here about. I set my depth to 2.255 but was getting anywhere from 2.253-2.267 I noticed the hollow points had some imperfection so I decided to measure a few. They ranged from 0.890-0.896(measured about 20). Will I need to measure these on a headspace gauge? I had my seating die properly tightened and all. All cases were between 1.75-1.76. Thought?

Variance in OAL with hpbts is not rare and it is likely only a small fraction of that runout is based on your dies, unless you did something horribly wrong.

More important is the length to the ogive in this case. HPBTs vary in length. If you wish to correct it you can presort your bullets by their length or utilize a meplat trimmer.

Should I re-seat any rounds over 2.260? What’s the minimum COAL? After measuring the bullets I did sort them and that really helped.

Even at the 2.267?

1) Case length can affect how much bearing surface is in a neck, but it has nothing to do with the overall length of a cartridge.

2) Sometimes measuring your SMKs and seating the longest to a length that fits your mags may not keep them all under the required length. Your die's seating stem should not be pushing down on the very tip of the bullet. Instead, it likely hits the SMK on a ring about 1/8" down from the very tip. So the actual seating depth probably depends on how the bullets vary at THAT point . . . not by how much schmutz (a technical term) is on the tip.

Long way of saying measuring the bullets' overall length takes a lot of time and may not be 100% effective? Have you encountered any that do not fit in your mags? Keep in mind the rare "too-long-too fit" can still be loaded and fired as a single.

I haven’t encountered any that wouldn’t fit in my pmags. Yea I can see the ring, ever so slightly, where the seating stem touches the bullet. But if there is variance between this point and the tip of the bullet that would affect oal.

HP bullets usually have 10-15 thou variance. I seat 5-10 long, pick the longest, seat it to 2.255", then seat the others and check for an average about 2.250" +/- 7 thou.

Plastic tipped or FMJs may have only 5 thou variance, but I seat them similarly.

0.014" variation is not explained based upon your measured bullet variation which is only about 0.006".

I'd investigate your seating process a little further.

Like the others have advised, you have to seat deeper than a nominal 2.260".

IMO, even 2.250" is too long and is asking for trouble.

Personally, I seat to 2.235" with my Hornady 75 gr HPBT-M's that are to be fed from a magazine.  This allows for variations at the tip, variations in the magazine size and even allows the cartridge to tip a bit within the magazine without binding.  No, it does not cause powder compression.

Who measures OAL?  Just seat until you hear powder crunch.

J/K op don’t do that lol
I just recently loaded some 77 gr smk hpbt and had good results with COAL. I used an rcbs seating die and they all fell +/-.004 at the most.