Help i need a fast answer help 911 - Strike Industries PDW Stock

I wanted the honey badger stock amd si pistol brace i actually am retarded and ordered the honey badger brace and si pdw stock so i must use it as is 3oo but i only have a 223 wylde 18 inch hunting barel to throw it on and it has a small proprietary pistol weight what can i do will stock work on my rifle lengths has system 18ninch?????