Starting to research the nuances. I think I prefer the finish on the Mk25 over the P226 Legion. However I'm not sure what the difference is between the MK25-10 and 10-B.

Based on this: https://www.gungenius.com/handguns/semi-auto/variation/1033645/sig-sauer-p226-mk25

I'll like do a SAO conversion (any suggestion for a gunsmith polishing... I don't have any problems doing a swap and basic dremmel polishing, but any gunsmiths to truly make it buttery?)

Sights aren't are a huge deal, I'll get night sights after everything is set up.

Also I've read various accounts of a SilencerCo barrel fitting without loss of accuracy on a Legion. What is the suggested suppressor for a threaded MK-25 TB?

Do you mean the "TB" 10? The "TB" is for the threaded barrel. I have a Cali. MK25 which comes with a different combo of parts. The Cali. version has 10 rounds but also has a magazine safety in which you can't fire the gun with not having a magazine in the chamber. The block is different to accommodate the parts which block the  trigger from functioning without a mag in it. No big, as that is an easy fix. Just remove the pin in the block and remove the parts. Now it can be fired without a magazine.

Sig does all kinds of crazy numbering/labeling with their pistols. I don't know what the "B" is exactly but it could be referencing different parts added. For example, not all MK25 pistols are the same. Some have the "short reset trigger kit" while others do not. Mine did not come with it. Also, depending on the time it was made, hammer struts and mainspring seats are different. Some have a "short" h.s. and a "long" seat. I swapped mine out to the E2 parts-"long" h.s. and "short" seat. It makes quite a difference in trigger pull, even with both types using the same mainspring.

I can't help with a SAO change out but I am sure others will be along soon to help out, if it can be done and the "how to".

Yeah I understood TB is for threaded barrel. Check the link I included. I think it has all the variants listed but it doesn't explain what the nomenclature means.

I figured I might as well get the TB right away from Sig. It adds a few ounces of weight but nothing substantial.

What sights do you prefer?

The night sights on them aren't bad but I would prefer the type on the Equinox pistols-fiber optic night sights. I am also contemplating eventually getting a contrast front night sight for easier acquisition.

Still no answer on the difference between the MK25-10 and MK25-10B?!?

Would it be better to post this on a Colt forum or query their service center directly?

Anything that is a -10 is going to come with a 10rnd magazine.

Attached File

With that link, where do you see any "B" other than "TB"?

Why not call Sig... 603-610-3000 Customer Service have the answer you are looking for....

This...

That's getting into territory of "you technically could, but why?" Skip the pointless mess you're creating for yourself and just get a SAO P226 to start with, IMO.