Factorio – Is There a Limit to the Number of Wagons a Locomotive Can Lead?

The hard limit is currently 255. We never tested it for more than 12 people on local network so different kind of problems might arise when lot of people play.

Edit: Since 0.14 the limit has been increased to 65535 and it might actually be possible to get that number of players online with exceptionally good network connection.

Not without mods.

If you need to do this and don’t want to use mods, you can just place a requester chest next to each turret and use an inserter to move bullets from the chest into the turrets themselves. (You could also just have the chest unload onto a belt that unloads into turrets if you don’t want to use so many request chests, but in practice there’s not much difference.)

If you are willing to use mods, the Logistic Turrets mod adds turrets that directly request bullets from the logistics network.