Piercing Round

Lore & Background

In the industrial sprawl that defines a Factorio base, the Gun Turret stands as a sentinel of iron and purpose. Its single input slot accepts either the humble Round or the heavier Piercing Round, and the choice is never trivial. A player watching a swarm of biters pour over a ridge will feel the difference immediately: standard Rounds chatter out a dense curtain of sparks, while Piercing Rounds thud with a deeper, more deliberate crack, each shot carving through a line of enemies rather than merely grazing the front rank. The crafting itself is unglamorous in the best Factorio way. An assembling machine clunks through its cycle, iron plate and gunpowder merging into a small, dense cartridge. There is no exotic material, no rare ore—just the steady, reliable output of a well-oiled production line. This is the philosophy of the game made tangible: power is not a single magical item but the result of layered, interlocking processes, each one feeding the next. Fans often describe the moment they first switch their turrets to Piercing Rounds as a small 'click' of understanding. The defense feels heavier, more committed. It is the industrial equivalent of a soldier choosing a heavier caliber for a known, sustained engagement rather than a quick skirmish. In a game where every belt, every pipe, every inserter is a decision, that single swap of ammunition is a quiet declaration of intent.

In Their Own Story

The night shift at the outer perimeter was quiet, which in Factorio meant the biters were gathering. Kira watched the minimap from behind a row of assembling machines, the rhythmic clunk of the crafting cycle a metronome in the humming dark. She'd run the numbers three times: at this swarm density, standard Rounds would burn through their magazine before the third wave cleared the kill zone. Piercing Rounds would not. She rerouted the belt, watched the small dark cartridges slide into the turret's input one by one, and set the fire rate to its new, lower cadence. The first volley cracked across the ridge like a hammer on an anvil, and the line of biters simply… stopped. Fell. Three deep. She exhaled, poured a cup of something hot, and let the machines keep counting.

Reader's Guide

Piercing Round is crafted at any Assembling Machine (1, 2, or 3) using 1 iron plate and 1 gunpowder. The gunpowder itself is a sub-recipe also crafted at an assembling machine, requiring iron plate and a secondary material. Upstream, iron plate comes from smelting iron ore in a furnace, so the full chain is: iron ore → iron plate, plus the gunpowder sub-recipe, all converging into the final cartridge. The sole consumer is the Gun Turret, which has a single ammunition input. You cannot mix Rounds and Piercing Rounds in the same turret; it uses whatever is in its input slot. This means if you want to switch types, you must drain and refill the turret, or dedicate separate turrets to each ammunition type. The typical bottleneck in this chain is not the Piercing Round crafting itself—any assembling machine handles it trivially—but rather the upstream supply of iron plate if your factory is also feeding steel, circuits, and other iron-hungry recipes. In practice, a single assembling machine producing Piercing Rounds can easily outpace one Gun Turret's consumption, so the bottleneck is almost always the turret's own fire rate and magazine capacity, not the production line. As your factory scales, you might find yourself running dozens of Gun Turrets along a long perimeter. At that point, dedicating one or two assembling machines to a continuous Piercing Round output belt feeding a shared buffer becomes the cleanest setup. The chain is short, simple, and scales linearly—no exotic prerequisites, no chemical plant required. It is the defensive equivalent of a well-maintained conveyor: unglamorous, reliable, and always there when the swarm comes.

Did You Know?

• The Gun Turret's single ammunition input means you must choose between Round and Piercing Round per turret; they cannot be mixed in the same unit.
• Piercing Round requires no exotic materials—just iron plate and gunpowder—making it one of the most accessible 'upgrades' in the defensive tech tree.
• Because any assembling machine tier can craft Piercing Rounds, you do not need to build a tier-3 machine just to produce them; a basic machine is perfectly sufficient.
• The choice between Round and Piercing Round is a genuine tactical trade-off: higher per-shot damage at a lower fire rate versus a faster stream of lighter hits, and the optimal choice depends on enemy density and your tu