Q&A for JP Enterprises Tuned And Polished Buffer Spring, .308 Rifle — 12 Questions & 9 Answers

For the PSA AR9 with the KynSHOT AR 9mm Heavy Damped Buffer, these JP Enterprises Tuned And Polished Buffer Springs for .308 rifles could work. However, I recommend using one of the Blitzkrieg Components Sprinco Power Buffer Springs which are recommend for use with the KynSHOT AR 9mm Heavy Damped Buffer. These springs can be found at the link below.
https://www.opticsplanet.com/blitzkrieg-components-sprinco-standard-power-buffer-spring-ar15-carbine.html

I recommend using the Carbine JP Enterprises Tuned And Polished Buffer Spring.

The JPS-OSC and the JPS-OSR are for the AR15. The JPS-OSC.308 and the JPS-OSR.308 are for the AR10.

As the 7.62x39 is a more powerful round, the .308 buffer springs should work better. This may still require some adjustment in the buffer weight though.

The two springs listed are for different length gas systems. If you are looking to build a rifle with an adjustable stock, you will need the carbine length. If you are building your rifle with a fixed buttstock, you will need the rifle length.

Yes, you will want the carbine buffer spring.

Yes, while it might not be a huge difference, there is a difference. I'm running this spring in my 9mm PCC 7.5" barrel build and it works perfectly.

OCR is a rifle length spring, and OSC is a carbine length spring.