It's not the easiest to find a lot of real info on the MPX. I was trying to find the ID of the rails.  The A2 appears to be partially covered by the rail, perfect for that SD look on the pistol SB15 model
I am also waiting on my Octane 45 in jail right now. I was hoping my Octane would fit nicely under the sig rail.
OD of Octane45 = 1.375 in
ID of MPX rail = 1.76 (according to a mod on sig forum)

Looks like it should be gtg!

Nice, I also have a 45 octane HD... and I will have an MPX pistol.... wish it came out in .40 though

Agree. I'd pick up a 10mm kit in a heartbeat also. Sounds like Sig had the user in mind in terms of modifications and such. We'll see how support is.

nvm

10mm wont fit in a 9/40 sized mag/magwell