In my setting, there is an alien world known as Totaria and an alien race known as the Totarians, who possess a special cell that lets them develop whatever organs, limbs, and creatures they want, somewhat like a super-stem cell.
With the super-stem cell, they built tools analogous to ours, from living creatures used as cars and public transportation, telescopes that utilize eyes and optic nerves to see long distances, and computers operating on neural tissue.
In fighting or war however, I'm having problems with certain aspects of their infantry equipment.
The issue I have is right now is that their primary firearm- a parasite shooting biological firearm known as a grub gun- is severely outclassed by 5.56 NATO and 7.62 NATO firearms, as seen here.
The Totarians use either muscle spasms or tightly wound muscles (like a crossbow) to launch a 9 ounce parasite at roughly 1000 fps to smash into someone. But as seen on the chart, it both lacks the energy to punch or severely deform body armor and the range necessary to get to the target in the first place.
In a gunfight, unless they're going door-to-door, they will be outgunned by common human infantrymen. It also means they lack snipers, so they cannot target exposed but far-away enemy troops or commanders. Also, because they rely on muscles to shoot, they need time to set them back into position or rewind them, making it so that they lack machine guns and thus are vulnerable to being suppressed by MG fire without counter-suppression fire available to them.
What routes could I go for in biotechnology (with living guns, living ammo, or guns/ammo made from once-living creatures) to make long-ranged weapons designed to fight 5.56 NATO and 7.62 NATO at the average distances of 25-300 meters? What should I be looking at that will let me have a machine gun and/or sniper rifle analog in biotechnology?
Thank you for reading this and helping me,