This blue coded recoil spring it is optimal for use with 5.56 AR-15s with a mid-length gas system and carbine buffer tube. Sprinco has extensively tested this setup and have concluded that it works great with 5.56 AR-15’s with a barrel length from 12.5” to 16” and either a standard or H2 buffer weight.
- For carbine length buffer tubes and mid-length gas systems
- Color coded blue
- Enhanced power
- Made from chrome silicon wire stock
- Heat treated and shot peened