By request, I have taken some pictures and put together a disassembly tutorial for my ISSC MK22. This should be enough to resolve the most common issues, however if you're facing major problems you may need to speak with a gunsmith or the dealer that sold you the firearm.
First off a quick disclaimer. I am not a gunsmith, nor is this tutorial intended for anyone who is not comfortable with the work involved. Please be safe and make sure your firearm is cleared before starting. I take no responsibility for what happens to your rifle with the work that you do on it. I'm always happy to help out if there are more questions but please don't expect me to be an expert.
Now, back on topic:
Here's what I have to start with. Pardon the mess and working space. I don't have the space for a proper work bench
A) Remove screw with flat head screwdriver
B) Same as A but this one was replaced with a HK style small push pin. now would be a good time to replace both A and B with pushpins
C) Remove hex screw and corresponding screw on the other side of the rifle
D) Fold the butt stock to expose this part. Remove this screw here.
E) Without removing the butt stock you can get a visual on these 2 screws here. Typically if you are experiencing light strikes after a few rounds, these may have backed out. It is a good idea to use blue loc-tite on these guys to keep them in place
First off a quick disclaimer. I am not a gunsmith, nor is this tutorial intended for anyone who is not comfortable with the work involved. Please be safe and make sure your firearm is cleared before starting. I take no responsibility for what happens to your rifle with the work that you do on it. I'm always happy to help out if there are more questions but please don't expect me to be an expert.
Now, back on topic:
Here's what I have to start with. Pardon the mess and working space. I don't have the space for a proper work bench

A) Remove screw with flat head screwdriver
B) Same as A but this one was replaced with a HK style small push pin. now would be a good time to replace both A and B with pushpins
C) Remove hex screw and corresponding screw on the other side of the rifle

D) Fold the butt stock to expose this part. Remove this screw here.

E) Without removing the butt stock you can get a visual on these 2 screws here. Typically if you are experiencing light strikes after a few rounds, these may have backed out. It is a good idea to use blue loc-tite on these guys to keep them in place
