MK2 Hammer Profile for different triggers.

[Dave74]

Closer inspection

[angrybear]

if you study closely the one one the left as a angled sear contact area,I found these hammers did not always work on serries 4 triggers,maybe they changed to sears on the serries 4 triggers over time,its something I've never realy studied but will start checking every serries 4 trigger from now on just to see if there is a slight difference between serries 4 trigger sears
KevG

Thanks Kev,
thinking about it the one on the left might well have come from a block with a mk3 trigger.