There, fixed for you. We've discussed this quite a bit over the years....powdered alloy mixture ( there are many and they are in everything) packed into a mold, fired, it shrinks about 10% IIRC and you can get above 99% solid metal. I think those circles are all injection ports. MIM'd isn't necessarily bad but there can sure be some bad engineering design, some improper alloy mixtures and what do I know about it????? I'm no metallurgist...I'm a brickologist. M1911I am really curious about Metal Injection Molding (MIM). I will look in the university library and see what find. I have seen plenty of investment castings, and I really don't think that's how most of the P22 parts are made. If my estimates are close, I think Walther only spends about $9.22 to make each P22 pistol. My guess is that the spend about $3.50 to make their 3.4" barrel.
Glocks only cost about $150 to make, and they almost never break.