Sig 226 Legion - optics mount and irons

[Lunker]

I bought a P226 Legion SAO recently and am looking to put a Trijicon RMR on it.
My first question is, do I really need an adaptor plate? I’ve had good experience with C&H, and would buy theirs. The only advantage I see to a plate is that it provides lugs to help reduce shear stress on the mounting screws. Is that really a concern on a 9mm pistol? Walther managed to do without lugs on their PDP series.
Also, I want to buy black serrated rear and front sights that will co-witness with the RMR. I have checked Dawson Precision and the Sig Sauer websites, and I’m not coming up with anything out of the box. All the tall sights from Sig are night sights. Before I have to break out my calipers, does anyone know if there is a package out there for this combo? And if not, do you know the front and rear sight heights I will need from Dawson?
Thanks in advance.

[FreedomFries]

I can't answer your question as to whether you need the filler plate with lugs, but I would suggest that you look at the Angry Bear tall black sights for the P320 which should share the same dovetail dimensions. The rear sight is total height of .417 similar to the Xray3 tall sight from Sig. They are nitrided, which I do not believe Dawson is.

I suspect you may run into a problem where many of the tall sights will obstruct a significant portion of your RMR window if you direct mount into your P226 R1P cut slide. Maybe the filler plate may even be nice to make them lower cowitness.

For reference, a .417 total height rear sight like the tall Xray3 matches up to same height as my Romeo2 built in rear BUIS when on my P226 R1P/R2 cut slide. The Romeo2 has quite a tall deck height.

[Lunker]

Thank you.
I decided to pop my RMR off a different pistol and see what it looked like on the Sig P226.
I think I really just need sights that are 10th of an inch or so higher, to get a lower 1/5 cowitness.
I think you’re right, that suppressor height sights would obscure the optic.

[fatdog]

Along those lines of Sig dovetail compatible sights, I got a set of the Strike Industries P320 sights and sent them off to Vulcan Machinewerx when they direct mill cut my Mk 25 P226 slide for an SRO and that combo worked great. No clue what the geometry works out for your gun however. These ended up being lower 1/4 to lower 1/3 cowitness and did not cost me an arm and a leg.

As for the bosses on the mount, I would point out that the Shadow Systems guns, I had a DR920, dispense with those completely and the direct mount is just the two screws, nothing else. I sent the Shadow down the road after a couple of thousand rounds because I simply did not like the gun, there was never a problem with the Holosun 407CO I had direct mounted with those two screws and nothing else holding it in place.

I tagged this to follow your experiences. Next year when I break down and buy a gun for Limited Optics division it will be a P226 SAO of some variety, not another 2011 of any variety.

[Archer1440]

I bought a P226 Legion SAO recently and am looking to put a Trijicon RMR on it.
My first question is, do I really need an adaptor plate? I’ve had good experience with C&H, and would buy theirs. The only advantage I see to a plate is that it provides lugs to help reduce shear stress on the mounting screws. Is that really a concern on a 9mm pistol? Walther managed to do without lugs on their PDP series.
Also, I want to buy black serrated rear and front sights that will co-witness with the RMR. I have checked Dawson Precision and the Sig Sauer websites, and I’m not coming up with anything out of the box. All the tall sights from Sig are night sights. Before I have to break out my calipers, does anyone know if there is a package out there for this combo? And if not, do you know the front and rear sight heights I will need from Dawson?
Thanks in advance.

Yes, you really need an adaptor plate. You want the Springer Precision plate, not the C&H. For am RMR you'll also want the Trijicon sealing plate.

Yes, lack of recoil bosses are a concern even though it's just 9mm. Walther re-engineered the PDP with a proper lugged interface "second generation" after the first year, and weasel-worded the reason for it, but the reason is obvious.

SIG's X-Ray suppressor sights co-witness fine with an RMR on a Springer plate.

If you don't want the tritium, then get the Dawsons. First thing to do is see what is on your SIG- 6/8 or 8/8. There are numbers on the sights. Then shoot groups at 15 yards to see what the actual impact is with that combination of sights and your intended load. Once you have that information, give Dawson a call, they'll know the correct combination to match the existing regulation with a higher set.

[TOTS]

To add on the above, I’m pretty sure you at least need a sealing plate to enclose the firing pin safety plunger. The RMR milling usually cuts through to the channel the plunger resides in.

[jwperry]

Are you going to have C&H drill RMR pattern holes? That's what I had them do. I use their sealing plate instead of Trijicon because it has a little lip that helps fill in the extra space in the optic channel. Makes for a snug fit.

If you do have them drill your slide, make sure they send you multiple length screws, I had issues with the screw on my extractor side bottoming out before I could torque it and I couldn't use a Holosun because that optic is totally smaller and neither screw would torque prior to bottoming out.

In regards to sights, I used XRay and they do peek into the window...but that's kinda the point of BUIS, right?

[FreedomFries]

To add on the above, I’m pretty sure you at least need a sealing plate to enclose the firing pin safety plunger. The RMR milling usually cuts through to the channel the plunger resides in.

The factory R1P/R2 cut on the RXP, Legion optics ready, and Pro Cut slides have the safety plunger spring hole cut less deep I think. It is not exposed by the optic cut.

Are you going to have C&H drill RMR pattern holes?

I believe some of the Legion P226 optic ready slides and the the Pro Cut slides have both the RMR and DPP/R1P/R2 holes already drilled and tapped. So he may just need to get a filler plate if not wanting a gap for the RMR, but the RMR screws may thread in fine without aftermarket modification. I have 2 of the Legion P226 LE/military Nitron finish version and these only had the DPP holes but I have heard many of the later slides are more multi footprint adaptable.

[Archer1440]

The factory R1P/R2 cut on the RXP, Legion optics ready, and Pro Cut slides have the safety plunger spring hole cut less deep I think. It is not exposed by the optic cut.



I believe some of the Legion P226 optic ready slides and the the Pro Cut slides have both the RMR and DPP/R1P/R2 holes already drilled and tapped. So he may just need to get a filler plate if not wanting a gap for the RMR, but the RMR screws may thread in fine without aftermarket modification. I have 2 of the Legion P226 LE/military Nitron finish version and these only had the DPP holes but I have heard many of the later slides are more multi footprint adaptable.

The latest Pro Cut slides have the correct hole LOCATION but (inexplicably) absolutely not the correct thread pitch or depth to use normal RMR/SRO screws. It is not possible to mount an RMR without either using a mounting plate, or drilling and re-tapping the holes and using extensively modified screws- which would lead to both a fore and aft air gap with no bosses- a Very Bad Idea.

As I said, get the Springer plate and use that. It comes with the correct screws, fills the gap (to the point where fitting- or a hammer whack- may be needed) and provides proper bosses for the optic. Do not *ick around with the hit or miss crap from C&H.

I've done this installation with both 226 Pro Cut and 229 Optics Cut Legion slides. Zero issues with both if you do the install to torque spec and use Loctite 248.

[JCN]

The latest Pro Cut slides have the correct hole LOCATION but (inexplicably) absolutely not the correct thread pitch or depth to use normal RMR/SRO screws. It is not possible to mount an RMR without either using a mounting plate, or drilling and re-tapping the holes and using extensively modified screws- which would lead to both a fore and aft air gap with no bosses- a Very Bad Idea.

As I said, get the Springer plate and use that. It comes with the correct screws, fills the gap (to the point where fitting- or a hammer whack- may be needed) and provides proper bosses for the optic. Do not *ick around with the hit or miss crap from C&H.

I've done this installation with both 226 Pro Cut and 229 Optics Cut Legion slides. Zero issues with both if you do the install to torque spec and use Loctite 248.

6-40 instead of 6-32 to prevent interference.