Meprolight sights on Sigma 40F

RDub01 · February 23 2016 05:42:02 PM MST

Hello
I received a set of Meprolight night sights ML-12740 S&W SIGMA as a gift and after installing them, I discover that the gun shoots six inches low at 25 yards with the same ammo that shot point of aim with the factory sights.

Not sure yet if I'm going to get anywhere with this company.. sent out some emails but haven't gotten anywhere yet..

My question is, how much would have to be machined off the front sight in order to make up for six inches at 25 yards?.. Or is this even practical to consider? This is the first time running into this problem with a handgun.

The obvious solution is to get this company to send a correct kit for my gun, but don't know it that will happen.

Thanks for any help

sqlbullet · February 23 2016 08:20:54 PM MST

Not as much as you might think. I would say it is doable

RDub01 · February 23 2016 08:53:52 PM MST

Well thats what I'm wondering. A very minute adjustment in windage makes a significant correction..

DM1906 · February 23 2016 10:42:48 PM MST

6" at 25 yds. is 24 minutes. That's a lot for an optic, but not as bad as it sounds for a short sight radius, such as the Sigma. There are different sights for different Sigma models. The ML12740 is fitted for the V series. You could start filing on it, but I wouldn't. I suggest calling ML, and hear what they have to say about it.

RDub01 · February 24 2016 06:05:28 PM MST

Just got an email back today.. They want me to send the kit back and let them inspect it to see if it's the correct one..

One thing I noticed while installing the kit.. I've only done this twice so I'm not an expert by any means, but all the others I've done the front sight 'fit' into the machined opening quite tightly. This time, the front sight was loose in the opening.. enough to where I could wiggle the sight back and forth a little bit. A tight screw and some Loktite is keeping it in place. Does this sound right?

So I removed the new front sight and compared the height to the factory sight. The factory sight measures .161" . The new sight measures .188".. a difference of .027". No wonder... The factory and the new rear sights were identical in height.

I sent this along with my email response.. See what happens.

DM1906 · February 26 2016 10:31:25 PM MST

S&W is not Glock. There isn't much interchangeability between the different Sigma models. Actually, they are more interchangeable with Glock parts than themselves (and the reason for the law suits). It's probably the wrong sight. The front sight is too tall and doesn't fit. It should fit so tight it requires pressure to install, and it should shoot point-of-aim at 15-25 yds.

RDub01 · February 27 2016 09:04:38 AM MST

Yes, pretty sure it's the wrong sight for this gun..
Funny.. The guy that responds to my emails has been, up to now, pretty fast to reply, but since I replied with the above measurements on the 24th, I haven't heard a peep since then.. Hmm..

sliclee · April 13 2016 08:37:15 PM MDT

I don't know if this applies to your sight but some where around the last week or so I read about "thermal" problems with some of these electronic sights, under certain conditions your rifle can hit the point of a pin at 100 the sight changes your off by a foot. The company or companies won't talk about this problem.
One of the companies didn't tell our govt about this and when confronted Im not sure what happened.

DM1906 · April 14 2016 12:27:51 PM MDT

Quote from: sliclee on April 13 2016 08:37:15 PM MDT
I don't know if this applies to your sight but some where around the last week or so I read about "thermal" problems with some of these electronic sights, under certain conditions your rifle can hit the point of a pin at 100 the sight changes your off by a foot. The company or companies won't talk about this problem.
One of the companies didn't tell our govt about this and when confronted Im not sure what happened.

Meprolight sights in this discussion are Tritium capsule sights, similar to Trijicon night sights. No electronics involved.

On that note, I use dozens of "electronic" type sights of many mfg's, holographic dot/retical, dot-optics, ranging scopes, etc, and never experienced any "thermal problems". El-cheapo Chinese knock-offs, perhaps, but I don't use those for anything important, and they haven't experienced that, either. I have returned some optics for defects, however. Just did that this morning with a Burris FFIII.

RDub01 · April 28 2016 10:19:04 PM MDT

Just an update..
The local pistolsmith took .030" off the bottom of the front sight and installed it on the slide. Now the gun shoots 180gr bullets right on the money at 25 yards. Still shoots the faster lighter bullets a little low, but that's to be expected.
Anyway all is good now.