bilbo
02-09-2015, 11:06 AM
Hi All,
I've never really been one to modify my guns but I've grown attached to my CM9 and find myself wanting to "make it my own". Like many, my eyesight is getting worse with age. After investigating XS Big Dot sights I just couldn't justify $150-$200 for sights on a $299 gun. I have access to a machine shop so I figured I'd try my hand at making my own. While researching this goal I went looking for the largest diameter fiber optic I could find. That led me to the TruGlo .120" Fat Bead universal shotgun sight... which is more-or-less exactly what I was going to try and build. A couple days later Amazon dropped one off for a paltry $14.
First order of business was to carefully remove the front sight. I clamped the original sight in a smooth vise. I then used a soldering torch to carefully heat up the mushroomed ends while gently pulling up on the slide. The sight popped right out leaving the mounting nubs intact so I can replace it if I choose.
Next I drilled and tapped a 3-56 hole directly between the two factory holes. You might be able to do this with hand tools if you are *really* good, but I wouldn't try it. I used an old Bridgeport to drill hole then locate the tap.
You are pretty much at the mercy of where the tap starts cutting the threads as to where the sight will line up. I shaved down the base of the sight until it squared up tight... Actually, I went a little too far and ended up using a piece of foil as a shim. A bit of blue threadlocker and it was on. (I have new found respect for people how manage to take great pistol pictures with a phone.)
http://www.borton.org/images/guns/frontsight.jpg
http://www.borton.org/images/guns/sightpicture.jpg
After several tries these where the best pics I could get. The sight picture above is not really how it appears to my eye so I 'shopped the dot bigger to approximate how it actually looks to me:
http://www.borton.org/images/guns/sightpicture-modified.jpg
Honestly, I thought it was going to fly right off... But, after 100 rounds of WWB and 50ish rounds of misc SD ammo, it is seemingly still firmly attached. Using the sight picture above the impact point is "combat" style, right behind the dot. My accuracy suffered a bit at distance but I can still keep all rounds on a 8.5"x11" piece of paper pretty easily at 30'. It does seem to me that the large FO dot is easier to pick up than the factory white dot sight accept at extremely low light levels.
So far I'm pleasantly surprised at the results of this experiment. I'm going to shoot it like this for a while and see how long term durability is. Perhaps my accuracy will get better with more practice. I'm thinking of serrating the front of the slide and perhaps a bit of a melt. If I decide I like this sight I will probably order another one (and be more careful) so I don't need the shim. Otherwise I may go to one of the Dawson front sights. They seem to be highly regarded.
Anyway, I just thought I'd share my experiment...
I've never really been one to modify my guns but I've grown attached to my CM9 and find myself wanting to "make it my own". Like many, my eyesight is getting worse with age. After investigating XS Big Dot sights I just couldn't justify $150-$200 for sights on a $299 gun. I have access to a machine shop so I figured I'd try my hand at making my own. While researching this goal I went looking for the largest diameter fiber optic I could find. That led me to the TruGlo .120" Fat Bead universal shotgun sight... which is more-or-less exactly what I was going to try and build. A couple days later Amazon dropped one off for a paltry $14.
First order of business was to carefully remove the front sight. I clamped the original sight in a smooth vise. I then used a soldering torch to carefully heat up the mushroomed ends while gently pulling up on the slide. The sight popped right out leaving the mounting nubs intact so I can replace it if I choose.
Next I drilled and tapped a 3-56 hole directly between the two factory holes. You might be able to do this with hand tools if you are *really* good, but I wouldn't try it. I used an old Bridgeport to drill hole then locate the tap.
You are pretty much at the mercy of where the tap starts cutting the threads as to where the sight will line up. I shaved down the base of the sight until it squared up tight... Actually, I went a little too far and ended up using a piece of foil as a shim. A bit of blue threadlocker and it was on. (I have new found respect for people how manage to take great pistol pictures with a phone.)
http://www.borton.org/images/guns/frontsight.jpg
http://www.borton.org/images/guns/sightpicture.jpg
After several tries these where the best pics I could get. The sight picture above is not really how it appears to my eye so I 'shopped the dot bigger to approximate how it actually looks to me:
http://www.borton.org/images/guns/sightpicture-modified.jpg
Honestly, I thought it was going to fly right off... But, after 100 rounds of WWB and 50ish rounds of misc SD ammo, it is seemingly still firmly attached. Using the sight picture above the impact point is "combat" style, right behind the dot. My accuracy suffered a bit at distance but I can still keep all rounds on a 8.5"x11" piece of paper pretty easily at 30'. It does seem to me that the large FO dot is easier to pick up than the factory white dot sight accept at extremely low light levels.
So far I'm pleasantly surprised at the results of this experiment. I'm going to shoot it like this for a while and see how long term durability is. Perhaps my accuracy will get better with more practice. I'm thinking of serrating the front of the slide and perhaps a bit of a melt. If I decide I like this sight I will probably order another one (and be more careful) so I don't need the shim. Otherwise I may go to one of the Dawson front sights. They seem to be highly regarded.
Anyway, I just thought I'd share my experiment...