I snapped several pictures of several different configs/generations of MCX, just for the comparison. Ill detail below, but let me know if you have any questions.
First off - what config if your rifle/barrel/plug that you posted? I ask because every caliber/barrel length is going to be different. Some more discernible than others.
L to R:
9" 300BO Legacy
11.5" 556 Legacy
6.75" 300BO LVAW
16" 556 Legacy
6.75" 300BO Virtus
5.5" 300BO Virtus/Rattler
16" 556 Virtus
9" 300BO Virtus
Attached FileCloser look at the Legacy plugs:
Attached FileCloser look at the Virtus plugs:
Attached FileNote:
1.) Some plugs are very, very well used and others are brand new pulled from brand new pistons. You can see on the used plugs which setting is used the most.
2.) Some ports are more easily discernible between the size, others are much less discernible to the eye - changes could be as simple as tapering into the port or just a slight change in diameter
3.) When comparing plugs, make sure you are comparing apples/apples - as the different length barrels and calibers will have different size ports.