Public Service Announcement on Palmetto State Armory Ruggedized Miniature Reflex Optics Slides (and other mfgs/models/styles)
Mounting an optic on a pistol is serious business and perhaps my recent experience will enlighten those wishing to do the same.
I went to a steel shoot match a week ago and in the later stages noticed my accuracy was falling off. I probably should have checked the gun but got distracted.
Once back home inspecting the gun, I noticed the screws securing the optic had come loose! I was lucky it didn’t come off and smash me in the face! There was also slight rub damage to the bottom of the optic but not bad enough to affect function or secure mounting.
This slide was a warranty exchange from PSA and I had to transfer the optic and used the same screws that I thought would have sufficient holding power initially but I was wrong. They WERE the only screws supplied that did not “bottom out” on the threads and leave the optic loose. An extra drop of Loctite was not enough to keep the optic secure after 150rds.
What I mean by screws “bottoming out” is that the screw has come to the end of the cut threads and will rotate no further. Forcing the screw deeper will likely snap it off in the screw hole! (see warning that follows)
Looking over the “instructions” that came with the slide, apparently PSA had already warned me to use the longer screws they provided when mounting an optic. Problem was, those screws bottomed out so I would have to tap the threaded holes deeper than PSA had. The PSA supplied screws also take a different wrench than the Torx that Holosun provided. The size of that wrench (not included) is 5/64” internal hex (Allen). Those are #3 on the item list.
I’m not sure about other slides/optics styles where the optics mounting screw holes will go, but in this Gen3 Glock-ish PSA Dagger slide, one screw goes into a blind hole on the left side (as you hold the gun) and one screw goes into an open hole on the right side. It is important to note that the open hole actually enters the extractor plunger bore.
If you haven’t already, completely disassemble the slide (you can leave the sights installed). Put the parts where they won’t get metal shavings on them.
With safety glasses on, and using a 6-32 tap that I blunted the pointy end of on a grinder so it would tap deeper, I tapped the blind hole on the left about 1-1/2 rotations of the tap (or about 3/64”) deeper until it bottomed. Every hole is different so use your own judgment on how deep to go. BTW, for best performance always clean a tap after EVERY hole.
WARNING! I’ve tapped 1000s of holes in my lifetime so I have a “feel” for when a tap (or screw) bottoms. What this means is the tap has come to the bottom of the drilled hole and will go further. If you forcefully bottom the tap and it breaks in the hole, it will be economically impossible to remove the remnants of the hardened tap! You won’t necessarily ruin the slide but you WILL make it near impossible to safely mount an optic OR the cover.
Moving on to the right side, I tapped the open hole until it entered the extractor plunger bore (1-1/2 turns?) then backed it out. The cuttings from both holes were then blown out with compressed air. Alternately, you could forcibly blow with your mouth but just don’t get saliva or food particles in the gun…
Using the longer PSA screws I test-mounted the optic. Both screws were able to fully tighten and properly secure the optic. BUT, the screw on the right side protruded into the extractor plunger bore (see pics). I've also shown the plunger and drill bit will not go all the way into the bore. This is not acceptable so the screw was removed and I ground off a half-thread at a time until it wouldn’t protrude. Measuring and comparing the shortened right screw with the left screw there was a difference of about .03” (1/32”).
Technically, since the plunger is thinner in this area, you might get away with not having to shorten the screw, but you will have to remove the optic screw to get the plunger out.
I used the shank end of a 5/32” drill bit in the extractor plunger bore to scrape any shavings from the inside of the tapped hole then blew out all of the bores in the slide.
I remounted the optic with blue Loctite 242, making sure the screw no longer protruded into the bore. I tightened until the wrench had a slight bend in it with one finger and would tighten no more. Using a Qtip, I dabbed up any excess Loctite that may have entered the bore so it wouldn’t foul the plunger. I tipped the slide upside down and allowed the Loctite to dry overnight but I’m sure I could have reassembled and put back into service.
Time will tell if the screws loosen again but to keep track I put a couple paint dots on the top of the screw heads and will check to see if they move after a stage or range session.
Mounting an optic on a pistol is serious business and perhaps my recent experience will enlighten those wishing to do the same.
I went to a steel shoot match a week ago and in the later stages noticed my accuracy was falling off. I probably should have checked the gun but got distracted.
Once back home inspecting the gun, I noticed the screws securing the optic had come loose! I was lucky it didn’t come off and smash me in the face! There was also slight rub damage to the bottom of the optic but not bad enough to affect function or secure mounting.This slide was a warranty exchange from PSA and I had to transfer the optic and used the same screws that I thought would have sufficient holding power initially but I was wrong. They WERE the only screws supplied that did not “bottom out” on the threads and leave the optic loose. An extra drop of Loctite was not enough to keep the optic secure after 150rds.
What I mean by screws “bottoming out” is that the screw has come to the end of the cut threads and will rotate no further. Forcing the screw deeper will likely snap it off in the screw hole!
(see warning that follows)Looking over the “instructions” that came with the slide, apparently PSA had already warned me to use the longer screws they provided when mounting an optic. Problem was, those screws bottomed out so I would have to tap the threaded holes deeper than PSA had. The PSA supplied screws also take a different wrench than the Torx that Holosun provided. The size of that wrench (not included) is 5/64” internal hex (Allen). Those are #3 on the item list.
I’m not sure about other slides/optics styles where the optics mounting screw holes will go, but in this Gen3 Glock-ish PSA Dagger slide, one screw goes into a blind hole on the left side (as you hold the gun) and one screw goes into an open hole on the right side. It is important to note that the open hole actually enters the extractor plunger bore.
If you haven’t already, completely disassemble the slide (you can leave the sights installed). Put the parts where they won’t get metal shavings on them.
With safety glasses on, and using a 6-32 tap that I blunted the pointy end of on a grinder so it would tap deeper, I tapped the blind hole on the left about 1-1/2 rotations of the tap (or about 3/64”) deeper until it bottomed. Every hole is different so use your own judgment on how deep to go. BTW, for best performance always clean a tap after EVERY hole.
WARNING! I’ve tapped 1000s of holes in my lifetime so I have a “feel” for when a tap (or screw) bottoms. What this means is the tap has come to the bottom of the drilled hole and will go further. If you forcefully bottom the tap and it breaks in the hole, it will be economically impossible to remove the remnants of the hardened tap! You won’t necessarily ruin the slide but you WILL make it near impossible to safely mount an optic OR the cover.
Moving on to the right side, I tapped the open hole until it entered the extractor plunger bore (1-1/2 turns?) then backed it out. The cuttings from both holes were then blown out with compressed air. Alternately, you could forcibly blow with your mouth but just don’t get saliva or food particles in the gun…
Using the longer PSA screws I test-mounted the optic. Both screws were able to fully tighten and properly secure the optic. BUT, the screw on the right side protruded into the extractor plunger bore (see pics). I've also shown the plunger and drill bit will not go all the way into the bore. This is not acceptable so the screw was removed and I ground off a half-thread at a time until it wouldn’t protrude. Measuring and comparing the shortened right screw with the left screw there was a difference of about .03” (1/32”).
Technically, since the plunger is thinner in this area, you might get away with not having to shorten the screw, but you will have to remove the optic screw to get the plunger out.
I used the shank end of a 5/32” drill bit in the extractor plunger bore to scrape any shavings from the inside of the tapped hole then blew out all of the bores in the slide.
I remounted the optic with blue Loctite 242, making sure the screw no longer protruded into the bore. I tightened until the wrench had a slight bend in it with one finger and would tighten no more. Using a Qtip, I dabbed up any excess Loctite that may have entered the bore so it wouldn’t foul the plunger. I tipped the slide upside down and allowed the Loctite to dry overnight but I’m sure I could have reassembled and put back into service.
Time will tell if the screws loosen again but to keep track I put a couple paint dots on the top of the screw heads and will check to see if they move after a stage or range session.
