Information is definitely out-dated, and you shouldn't really take it to heart.
The UTAH-23 is a shoulder attachment which existed during DEMO for the M4A1.
This effectively reduced spread when ADS'ing, making it more accurate, but made the hipfire spread worse, making it slightly more inaccurate in third person.
When a suitable amount of supplies existed, the M4A1 started to use the UTAH-23. It was a reliable attachment and most models of the M4A1 had this, but production had to be halted as the attachment was considered a waste.
The resulting mass scrap of unused UTAH-23 attachments lead to the construction of the Shoulderpad when survivors really needed it.
- This is mostly beneficial for first person, ADS gameplay.
- Shooting in third person will make the gun miss more targets.
- Even with this attachment, don't go all trigger happy and fire rounds into the far abyss. The gun you are shooting is an automatic.
- This is good with the XPS3-2. You can snipe far away zombies with the right Custom Sightmark.
- Semi-auto mode is recommended if you do this.
- This is similar to the Shoulderpad attachment for the Skorpion.
- Its full name is the "UTAH-23 shoulder-support".