Sierra 183 SMK Length Change?

• Bullet type:
  The updated design primarily affects Sierra's MatchKing line of bullets, designed for competition shooting.
• Design change:
  The new 183 grain bullet has a longer ogive and a more pointed meplat, which helps it fly more efficiently and provides better accuracy.
• Benefit:
  This modification leads to a higher ballistic coefficient, allowing the bullet to better resist wind drift and maintain velocity over longer distances.

Cole440 said:

Anybody know if Sierra has changed the length of the 7mm 183 SMK since they introduced it?

Long story short I recently picked up a 284 F-Class rifle that came with some loaded ammo from the P.O. I started measuring some of the loaded ammo just to see where he was running the OAL. Noticed variation, that led me here.

I'm seeing about a 0.025" difference in the bullets I have. Both from base to ogive and from base to tip (though this measurement is predictably less consistent). There are two distinct lengths, one group measures 0.625" and the others measure 0.599" base to ogive. The two groups have ever-so-slightly different boat tails also. Bearing surface and everything else looks identical. All weigh in right at 182.5-183 gn.

All of his notes indicate that they are 183 SMK and the weight agrees. I'm thinking it has to be an OAL change or a significant lot-to-lot variation. I have no further info about when he purchased the bullets.

The 183 SMKs I just purchased are within 5 thou of the shorter group . Leading me to believe that the longer group is older.

I'll shoot them all just the same, just curious!
Merry Christmas all,
Cole

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