JP silent captured springs

[iMagUdspEllr]

Does anyone know what this means?

http://www.jprifles.com/1.4.7.2_os.php :
"The JPSCS is not compatible with any 9mm AR variant or any blowback system using a solid (weighted) carrier."

I don't know what a solid/weighted carrier is? Thanks in advance.

 

[James K]

Another AR gadget. It looks like they use a small diameter spring on a guide rod instead of the full diameter spring that gives the AR that neat "twannnnggg" when loading the first round.

Some guns of that general AR appearance, like .22's, are blowback, not gas operated, and apparently their spring won't work with those or with the 9mm carriers and bolts. The regular 5.56mm/.223 carrier is hollow, where those guns have a solid carrier to get the mass needed for blowback operation.

Jim

 

[iMagUdspEllr]

Thanks a bunch for the rapid response!