Contemplating a CS40 locally with the white dot Novak sights. In searching I've seen the M&P front sight will interchange with the 3rd gen dovetail but can't find a solid answer if the rear dovetail is the same or close enough to modify. I'd like to install XS big dot sights if I got it and they are no longer offered by XS. Thank you in advance for any help.

Hi Dave,
I am not aware the M&P sights are compatible with the 3rd gens...if you someone could verify this and post some pics it would be great...

Some of the CS40 sight options that I am aware:

1) Stock sights...work great IMHO...you could get rid if the rear white dots using some "citristrip" and a toothpick. The rear aperture is a bit "narrow" for my taste...you could open it up to .140" or .156" for faster sight acquisition.



2) You could add a Dawson fiber optic to the front and keep your factory rear (stock or modified). Dawson makes excellent sights and the front comes in diverse heights and widths to match your needs.

3) If you like night sights, I believe Trijicon still makes night sights sets for 3rd gens. They also sell the front only if you want to keep the stock rear (some people, like me, don't like the 3 dot system)

4) Maybe (maybe) XS sights has some sights left...just not listed in their website...give them a call...they used to have good customer service...

5) LPA rear: LPA makes nice rear adjustable sights...some people find them a bit bulky for EDC...I think they are a great options. You can find several online...


CS 40 slide with a rear LPA compact sight...

hope this helps...

Guzzi

I have before me, a new Novak sight for a gen 3 Smith, a gen 3 slide, and a rear sight removed from a M&P. At first glance I thought they would interchange. However, the base of the M&P sight is about .030” wider. The angles appear to be the same, so it might be pretty easy to open up the dovetail enough to fit. Or maybe just trim the sight. The front sights are interchangeable. Been there, done that. No additional speculation required.

Thank you, excellent info guys. I definitely could handle filing 0.03 off the sight to install.

A word of caution. That may not be as simple of a task as it sounds like. The base of the sight that goes in the dovetail is essentially an Isosceles triangle. If you reduce the height of the baseline, you gradually reduce the width of the base. But, the rear part of the sight has very little clearance between the sight and the top of the slide. It’s possible that this surface will need to be reduced for clearance.

I looked at the Dawson website and saw that they only offer sights for the 5906. Since they offer a number of different height options, it would seem that I could find one to match a 3914.

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Can open, worms everywhere.

Just a note here, if you file the bottom of a sights dovetail, you lower the height of the sight. A couple of thosandths isn't that big a deal. OTOH, 0.030 in is a big deal. On a fairly typical handgun sight separation 0.005 in is good for 1 in change of impact at 25 yards.

Just to make it crystal clear the sight is longer front to back or thicker top to bottom?

Normally to fit a dovetail sight I would use a safe sided file and reduce the length front to rear not changing the height of the dovetail top to bottom. If the M&P sight dovetail is thicker top to bottom all the warnings here are spot on about having to adjust the overhang and sight height as well.

The plus side of the xs sight is that at get off me ranges dot the I and the big dot goes on target. At 25 the top of the dot is your POA/POI. While not as precise as traditional sights I haven't found anything quicker to aquire for me at social distances and its fairly easy to regulate with a change in bullet weight or velocity.

On the Dawson sights... Those listed under 5906 will fit any of the small frame guns.

For the large frame guns ie. 45xx & 10xx, use those listed under E-Series 1911. These have the wider base that fits the wider cut in the bigger guns.

Dawson sights are a little bit more tricky to fit... These are made from a steel alloy called "stressproof" and it's not hardened so if you beat on these they are easily deformed. And the height of the base is just right so you cannot scrub the sight base on a stone to narrow it because doing that will leave the base too short then the blade will interfere when trying to install the thing. My method is clamp the sight by the blade upside down on the mill and with a 75° cutter shave about .002 at a time off the rearward facing angled surface on the base until it's at the point where I can shove it in about half way merely by hand.

This is my preferred method for fitting the Dawson fronts. And I always use some manner of retaining compound

Cheers
Bill

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Because they don't make a .46

The difference is front to rear. 60 years ago, I could have accurately calculated the amount that needed to be removed from the base to achieve the desired width. Too many days have passed without exercising those particular brain cells.