Bernina Express

sure. Absolutely.

Do note that if you are asking about just now the rail line at the north end of the train between Milano Centrale and Tirano (careful - Tirana is in Albania, about 1400 km from where you want to go) is under repair and there is currently a rail replacement bus for that segment. Check timetable carefully.

But certainly doable.

Stay on the regular hourly train on the Bernina route - you'd be hard pressed with your schedule to get the named trains. Same scenery, same speed, windows which open, and no reservations needed.

Ha, when I first saw this post, I immediately thought of my Bernina sewing machine and wondered why sewing machines were being discussed on the forum. 😊

everything you ever wanted to know about the Bernia Express

https://www.seat61.com/trains-and-routes/bernina-express.htm

it's on my bucket list. I can't decide if summer or Winter would be better

Tony, are you in Milan now? If not, when will you be there?

If it is beautiful snowy mountains you wish to see, there is a shorter and easier journey you can make from Milan, with greater scenic reward, in my view. Plus you get a cablecar ride up to a car-free village, and a spectacular glacier. In the time it takes to get just to Tirano to start the Bernina Express, you would be in Bettmeralp.

See the photos on this website:

https://www.aletscharena.ch/en/activities/hiking

Although these show people hiking, it is not actually necessary to do any rugged hiking to reach the viewpoints. You can ride a cablecar to the top of one of the peaks, or a smaller lift to the top of the ridge.

The journey involves a train ride to Brig in Switzerland, a ride of under two hours on a EuroCity train with no changes. At Brig you change to a regional train heading east to Betten, just 15 minutes away. At Betten you board the cablecar for the ride up to the village over a 1000 meters above. From the village you are looking south across the Rhône valley to Alps in Switzerland and Italy. On a clear day you will see the Matterhorn in the distance. To see the mighty Aletschgletscher, you ascend the ridge behind the village by hiking 30 minutes up an easy path, or by cablecar.

Note that this is best if you can do it in the next ten days or so, as by the end of the month they will start track work on the line bwetween Milan and Brig, so it would take much longer than the 2.5 hours the schedule shows now. So if your visit is in September, this is not as attractive an option.

However, at the current time there is track work that disrupts the journey to Tirano, with a bus substitute, so it takes longer than usual to reach Tirano. So we can best help you with your mountain quest if we know when you are visiting Milan.

I see lots of people recommending the 'regular train' from Tirano to St. Moritz rather than the Bernina Express. Anyone know how to get information on that 'regular train'?

Basically, on the Bernina Railway, special "Bernina Express" panoramic express trains ("PE" on the SBB rail schedule) alternate with regular regional trains ("R" or "RE"). The former have the big floor to ceiling windows that don't open, and require reservations that sell out in high season. The latter usually have windows that open (not sure about the exact rolling stock situation on that route though) and do not require any sort of reservation. The route is exactly the same.

I remember studying for a day trip that I never had; at the time, leaving very early from Milan it was possible to do a day trip to St. Moritz, but Chur looked too distant for a single day. A possible diversion is going to St. Moritz via Bernina, then bus to Chiavenna; from Chiavenna a short railway line leads to Colico and then back to Milan. The thing is well possible and you have a different return itinerary, but you have to plan very carefully the times of the bus and the trains.

A similar itinerary could be possible via Chur: Milano-Tirano-Chur on railway, Chur-Bellinzona on bus via the St. Bernardino pass, then Bellinzona-Milano on train. Looks too long for a single day, however.

Responding to the person who asked how to get information on the regional trains going through the Bernina Pass: You need to look at Swiss trains at SBB,.ch.

Is it possible to a short poor man's train ride? We will be in Chur. It looks like there is a loop of sorts of scenic trains going through Davos, Filisur, etc. We have a rail pass, maybe just take normal trains on those scenic routes?

Lots of information on the scenic panoramic trains at myswissalps.com. They also have a forum which is quite good.

Railrider, the Albula railway to Samedan is already very scenic, with spiral viaducts/tunnels and great views. A round-trip from Chur to Samedan, which is worth of a quick walk-around, would be a lovely excursion.
If you are coming at a time when it is open, from Samedan you could extend the trip to the Muottas Muragl funicular - the views are great at the top, but it is a bit expensive and not covered by any pass as far as I know.
Looping via Davos is less interesting; I have never traveled thr short stretch between Filisur and Davos Glaris, but from Glaris to Landquart is nothing too special in comparison. Still pretty, but not as much.