They were probably the worst bolt action service rifle of both WW1 and WW2. They lack the sophistication of the best ones, the Lee Enfield and the Mauser 98. The updates in 1930, 1938, and 1944 were insignificant spins on a design that was mediocre in 1891.
Setting up a Mosin (and training yourself) to actually be useful is playing the game of gun ownership on hard mode.
You'll run into all kinds of obstacles. Here are some things I've found.
-Some stripper clips work well (from Gun Parts Corp).
-One stripper clip loading method works (grab the top round and use it to push the others down).
-The action screws always come loose under recoil.
-The rear sight can shift under recoil (e.g. from 300m to 400m after one shot).
-The bolts will stick, but not with brass ammo. Using brass ammo will do more than cleaning your chamber (by the way, do not put a fine polish on the chamber, as it is dangerous).
-The sights might not line up (e.g. 100m setting might match POI/POA at 100, but you might need 300m setting to match at 200m distance).
-The safety just requires a little technique. You need to put the butt of the rifle in the crook of your elbow and pull with your thumb and forefinger. But the safety can be dangerous if you let it slip.
-The handguards can slip if the retaining clips aren't doing a good job of holding them.
-They are so loud you will need to go with max hearing protection at all times. The flash and bang from the carbines is tremendous.
-You need a slip-on recoil pad with them.
-Ammo is not cheap anymore by any means.
-Triggers range from being so stiff it hurts your finger after a while to pull it to feels like a double action revolver trigger pull to modern hunting rifle.
-Even if the bolt isn't sticking it's hard to cycle the rifle quickly because it's a straight bolt handle, the bolt handle is short, and it cocks on opening. I always remove it from the shoulder to cycle it.
Some good points:
-Accuracy is no concern at all. I recently shot a ten shot group at 100 yards within 2.5" with an M38.
-Headspace is rarely a concern, but it headspaces on the rim and is super easy to check.
-Thin front sight posts are available from an ebay seller. They are nearly impossible to install but work well and you can file them down.
-Slings are readily available and work well.
-They draw enormous attention at the range.
Is it a good survival rifle? If you actually shoot your guns, sight in your guns, buy accoutrements and accessories for your guns, and test your guns, then sure you can kind of make it work. However, it will be totally outclassed by a Lee Enfield, Garand, or Mauser.
If you're the kind of person that likes to buy guns and then set them aside without setting them and yourself up properly, then what you're looking for is an AR-15.