hey kid you must be pretty butthurt that I said "badass pistol" haha lighten up. i have read lots of online reviews and asked people at the range about steel case ammo through their guns. for example, firing Tulammo through a revolver causes the casing to expand, and requires a screwdriver to punch out of the cylinder.
Look at
ammoseek.com to find the best prices on ammunition. For example,
1,000 rounds of 9mm Tula costs you $146, while
Link Removed costs you $177.85. You save $31.85 on 1,000 rounds. If you think that saving around $30 on 1,000 rounds of ammunition is more important to you than getting more reliable and significantly cleaner ammunition to train and practice with, go ahead. The bi-metal bullet will wear out standard rifling faster though. Also, indoor ranges generally prohibit bi-metal bullets as they spark when hitting a steel backstop and can cause a fire.
As for your "badass pistol" comment, it displays a certain mindset. Most persons with serious firearms training would not use that term, knowing that handguns pretty much suck in general and it is the operator's training that makes him or her "badass" and not the gear. If you look at Internet gun forums, you will realize that the vast majority of posts are about gear and politics, and not about mindset, tactics and skill. Gun enthusiasts spend thousands of Dollars on gear and many hours on posting about their gear and politics, but little-to-none of money and time on training. You seem to be one of them.
Your OP stated a number of things that lead me to believe that you have little-to-none training and that you are chasing common myths about firearms that are typically perpetuated by gear heads on gun forums. You said that you are looking for a handgun that can run steel-/aluminum-cased ammo. The big question is: Why? You said that such gun seems to be hard to find. That's not true at all. You do not mention any other parameters that such handgun must meet, such as size, caliber, action type, capacity. That's just odd. After all, you want to carry this gun, right?
As I said, get a Glock 19 and get some training to become "badass". The
classes I posted will provide you with such training: