The magazine is made of highly robust glass-reinforced composite, a durable material that’s not affected by changes in temperature. A composite magazine doesn’t change its structure when dropped (contrary to a metal magazine), ensuring reliable feeding.
What is a double-stacked magazine?
A double-stacked magazine stacks the ammunition into two rows instead of a single file. This way, you can fit more rounds into a single magazine. Having a thicker magazine adds weight, and there’s less recoil. The Sako S20 magazine is double stacked, but also center-feeding.