DISCLAIMER: I am NOT a gunsmith and I am in NO WAY advising you to disable, fiddle, or even look, at the innards of your firearm. You do so it's your own choice and I bear no responsibility. Guns aren't toys and if you don't know what you are doing then DON'T DO IT!
Okay, the deal with the "magazine safety" is that it disables the trigger anytime there is no magazine inserted into the pistol. While I understand that Ruger was trying to prevent incidents of people thinking the gun was unloaded because they'd dropped the magazine (not realizing a round was still in the chamber) I think this is a prime example of trying to idiot proof the world rather than teach these dumbasses the correct way to handle and check a firearm.
So they build in the "magazine safety" and suddenly in order to do just about anything with the gun you have to have a magazine inserted which is just unnatural to me (I have YEARS of training that says if you are going to work on a gun the magazine should be OUT of the gun).
Additionally it adds EIGHT extra steps to the disassembly/reassembly of the firearm (now being called the Magazine Cha-Cha) along with Ruger's usual "point it up, point it level, point it down" colorguard routine.
See below...all items in RED are due to the "magazine safety" and are no longer necessary after you disable the damned thing.
Ruger MK III 22/45
Disassembly
1. Pull Mainspring Housing Latch open
2. Swing mainspring housing out, removing mainspring housing and bolt stop pin.
3. Insert unloaded magazine
4. Point muzzele updard in a safe direction and pull trigger, bolt will drop out of receiver.
5. Remove unloaded magazine
6. Sharp rap forward on the rear of receiver will unlock barrel/receiver which can be lifted from grip assembly.
Re-Assembly
1. Safety must be in “F” (fire) position for reassembly.
2. Place Barrel/Reciever on grip frame, click into place (rearward).
3. Insert unloaded magazine
4. Point barrel up and pull trigger (to make the hammer fall flat)
5. Remove unloaded magazine.
6. Hold pistol flat, insert bolt
7. Insert unloaded magazine
8. Point muzzel at ground, pull trigger (hammer should fall full forward)
9. Remove unloaded magazine
10. Insert mainspring lock bolt assembly
11. Now point muzzel skyward, look for hammer strut
12. Guide hammer strut into mainspring cup
13. Close mainspring lock bolt assembly, being careful to capture hammer strut in mainspring cup.
14. finish latching mainspring lock bolt assembly.
Test assembly by pulling slide back and releasing, it should slide freely. In order to test fire (and release spring tension) you must Insert unloaded magazine to deactivate magazine safety and then the trigger will work.
After test fire Remove unloaded magazine and put pistol away.