How to deal with Pseudo Giants?

So Ill open up right away, I'm brand new to Stalker 2. I get mowed down by this psuedogiant I found recently and Im not entirely sure how to ice the sucker. I currently have a 10 round magazine M860 Cracker with 50 slugs, a AS VAL with 100 rounds of ammo and a PTM Silenced with 30 Armor Piercing rounds as well as 15 R5 Grenades, 14 Medkits and 24 Bandages.