Hornady 225 HPBT vs SMK 220
 

So after having just loaded up a 100 count box of SMK 220's to 300 BLK subsonic of 2.089" COL and 11.2gn of AA11680, I got the bug to think about building a better mousetrap...

Couple of my primary considerations:
economics
accuracy

Here are the facts as I know them:
Price (as per Midway for general availability, shipping may vary);
SMK 220: $41.99/100 or ~$.42 ea
Hdy 225: $33.99/100 or ~.$34 ea

OAL;
SMK 220: 1.494"
Hdy 225: 1.580"

BC;
SMK 220: .629
Hdy 225: .670

Comment: Meplat consistency definitely goes to the Hornady rounds for measuring OAL

Using the same seating stem w/o changing any of the settings, using Remington .221 Fireball cases resized and trimmed to 1.355" the COL's were:
SMK 220: 2.089" as prescribed (http://300aacblackout.com/)
Hdy 225: 2.144"

So far I'm seeing 3 factors coming to light, 20% saving, better ballistic coefficient and a steeper boat tail design and longer ogive, allowing for a COL closer to the lands. Barring benchrest testing (i.e. weight sorted brass, neck thickness and meplat uniforming, etc)...the economics alone are a clear winner.

I'll be doing some accuracy testing as soon as I get the chance but if someone gets to it before I do, please post your results!

I shoot the 225.

The actual subsonic BC of the Sierra 220 is 0.720. I had it tested on doppler radar at 1000 fps.

Did you test the 225?

I have to think that with the secant ogive very similar to the Berger VLD's, that the Hornady's still have a higher BC...regardless of the measuring method.

The only concern is that the tangent ogives tend to enter the throat more consistently when exposed to substantial jump... thus my initial reason for posting, economics & accuracy.

I've got the two sets of rounds loaded to identical specs...I just need the time to get to the range to test.

No. Just the 220 and 125 Sierra MK.