Well I finally got my new ML out yesterday and what fun. I shot both the 300 gr sst with supplied sabots and the 325 gr ftx with the mmp orange sabot both loaded very well. The sst loaded extremely easy the ftx after a few shots was a bear to get started but as soon as I did with the short starter the rest of the way was like butter. I had 100 gr pyrodex behind it and will play around some more maybe up to 120 next time out. Didnt get it totally dialed in but was pretty happy with where I got for the first time out. Not a huge fan of the sights but they could be worse, just seemkinda big at 100 hards they cover a good portion of the target so I sighted them in just below where I wanted to hit. I will for sure be shooting the 325 gr ftx and cant wait to get it back out there.
And to answer the question on the breech plug, yes on the northwest edition the breech plug exposes the musket cap with four holes that are drilled into it.