To anyone who's looking to buy the SCS320, please make sure you check the screw lengths before forcing them into the mounting holes or torquing them. Holosun accidentally sent out some screws slightly too long, and may dig into your extractor spring causing damage.
Now let me do the long version of the story. I've been a loyal Holosun fanboy and has owned easily a dozen of them. I've been happy with every single one. Once the SCS320 was announced I had to have it. When mounting it, I first found that the screws were hard to drive in, and the red dot was wiggling even when the screws seemed to have been tightened. I went further and was able to finally secure the red dot, not realizing what I had done. The second day after the loctite fully cured I went to the range the zero the red dot. The shooting was fine, the zeroing only took 3 rounds, but my P320 was failing to extract about 1/4 of the time, which was very odd. Fortunately (or unfortunately) I have had a similar experience with Riton MPRD on my Glock 48 MOS, where the right side mounting screw was too long and dug into the extractor rod, causing the extractor to malfunction. With the P320 it's even worse because I need to depress the extractor spring/plunger to remove the slide cover plate, and with the mounting screw in the way I can't even do that. After getting home I was finally able to take my gun apart and of course the extractor spring was badly and permanently damaged beyond repair. I reached out to my dealer and then the Holosun.ca rep (both are great gentlemen who responded immediately and took the matter seriously), and was told that the feedback has been provided to Holosun and they'll be sending slightly shorter screws in future production runs. Holosun also replaced my damaged parts.
Now onto how the problem occurred in the first place, the spec of the screw is M4 x 0.7 10mm. M4 is the diameter of the screw, 0.7 is the thread pitch, and 10mm is the length. The first two are easy but the 10mm is used differently in different industries. Some people include the head height of the screw in the 10mm, others don't. The screws that came with the SCS320 measured 12mm in total length, and 10mm in threaded length. I think Holosun meant to get 10mm in total length and 8mm in threaded length instead.
While James, the gentleman with Holosun.ca, promised to send me replacement screws when he receives some, I've also made an order of 100 screws from Amazon, which should arrive in about a week. To anyone who's run into the same issue as me, please feel free to reach out to me and I can ship you some screws when I have them (that's if they work properly of course).
Attached are a few pics of my nightmare.
Now let me do the long version of the story. I've been a loyal Holosun fanboy and has owned easily a dozen of them. I've been happy with every single one. Once the SCS320 was announced I had to have it. When mounting it, I first found that the screws were hard to drive in, and the red dot was wiggling even when the screws seemed to have been tightened. I went further and was able to finally secure the red dot, not realizing what I had done. The second day after the loctite fully cured I went to the range the zero the red dot. The shooting was fine, the zeroing only took 3 rounds, but my P320 was failing to extract about 1/4 of the time, which was very odd. Fortunately (or unfortunately) I have had a similar experience with Riton MPRD on my Glock 48 MOS, where the right side mounting screw was too long and dug into the extractor rod, causing the extractor to malfunction. With the P320 it's even worse because I need to depress the extractor spring/plunger to remove the slide cover plate, and with the mounting screw in the way I can't even do that. After getting home I was finally able to take my gun apart and of course the extractor spring was badly and permanently damaged beyond repair. I reached out to my dealer and then the Holosun.ca rep (both are great gentlemen who responded immediately and took the matter seriously), and was told that the feedback has been provided to Holosun and they'll be sending slightly shorter screws in future production runs. Holosun also replaced my damaged parts.
Now onto how the problem occurred in the first place, the spec of the screw is M4 x 0.7 10mm. M4 is the diameter of the screw, 0.7 is the thread pitch, and 10mm is the length. The first two are easy but the 10mm is used differently in different industries. Some people include the head height of the screw in the 10mm, others don't. The screws that came with the SCS320 measured 12mm in total length, and 10mm in threaded length. I think Holosun meant to get 10mm in total length and 8mm in threaded length instead.
While James, the gentleman with Holosun.ca, promised to send me replacement screws when he receives some, I've also made an order of 100 screws from Amazon, which should arrive in about a week. To anyone who's run into the same issue as me, please feel free to reach out to me and I can ship you some screws when I have them (that's if they work properly of course).
Attached are a few pics of my nightmare.
