This is really interesting. What brand 1911s can go through "mud, filth, and sand"? Or, how much does a person generally need to spend on a 1911 for that kind of durability/reliability?
Now, I didn't throw them in mud and run them over with a truck, or any of this stupid "torture" nonsense. Open carry, rain, mud, 4 wheelers. The 1911 was as dirty as I was, functioned fine. A proper 1911 is quite reliable in normal filthy, messy, circumstances. Just don't torture test it in a bucket of concrete dust or something.
Keep in mind, the .mil GI's all had the same ammo and mags. That's half the battle with 1911's, right there. The guns were tuned to the ammo and mags at hand. It wasn't loose slides that made the early 1911's reliable.
Generally: $2000+. Sand can't really get into the slide surfaces, if those surfaces are too tight for sand to fit into. And I use a thicker grease that further fills that void. But a cheap 1911 can also be reliable, if you fix where they cut all the corners cheaply. Mags, springs, extractor, grip safety, thumb safety, sights. Assuming the barrel is set right and the slide is straight.
The 1911 gets a bad rap from improperly built examples, and the millions of ammo and magazine combos available for it. Rough finish barrels, lame mags, odd/weak ammo, doesn't help either.