Fast answer: almost totally yes, any full size 945 magazine fits all the 945’s (except the very rare 945-40) and obviously, the short frame compact pistol magazines aren’t long enough to lock in to a full size.
Longer answer:
The 4506 and 945 magazine tubes, followers, spring, floor plate and capacity are the same, the ONLY difference is the location of the cutout to lock them in to the pistol.
When the 945 first debuted, the magazines they shipped were exactly 4506 magazines with a second notch added in the correct place. They got a warning written on them, “FOR MODEL 945 ONLY” but in my experience, this is not exactly true.
These dual notch magazines will work in both the 945 and the 4506, but as you might guess, if used in the 4506 you must ensure you insert past the top notch and lock in to the lower notch. I believe this is why they carry the bold 945 ONLY warning. In a duty/defense role with a fast and pressure magazine change, a dual-notch magazine in a 4506 would be a bad idea.
I will also say this… when you look at the early dual notch magazines you may see the notch and the small slice of metal and think “wow, that looks fragile…”
I am here to tell you that it is absolutely NOT fragile. It is hell for stout.
Lastly, one might look at one of the early original dual-notch 945 magazines and say, “hey, maybe I could modify a 4506 magazine and replicate that!”
In my experience, yes, you can! I cannot imagine pulling it off well or accurately with a Dremel, but some folks are pretty skilled. I have six modified magazines that my buddy did with a mill that weighs as much as my car.
These magazines are -ALL- that I use for my 945’s. My OEM official 945 mags are tucked away. I only use these six modified magazines.
If I were still in contact with my buddy, maybe I would make a slew of them… however I am not, and no, I cannot replicate this feat for others. But anyone with the equipment surely can.
