What size do you keep on hand?

[KnotRight]

For a 223 or 300 BO

Spring for an AR Carbine (inches)
Spring for an AR Pistol (Inches)

Buffer for an AR Carbine
Buffer for an AR Pistol

I have a few lowers laying around and do not want to hunt around for parts when I start to build them out.

 

[Catfish]

I use the same std carbine spring and buffer in everything 223 and 300BLK. pistols, sbrs, carbines and rifles, all suppressed. I don't have a 300bo so I can't help you there

 

[Clicker]

The Tubb flat wire spring works in both carbine and rifle, problem solved!