Anyone tried a JP buffer with no weights?

[ltdmstr]

I have a AR-type SBR with 10.5" barrel in 300 BLK and loaded up some subsonic rounds with Trail Boss.  I tried them with a suppressor and they are super quiet and would be great for indoor use.  The problem is, they won't cycle the bolt, and most times won't even eject the empties.  I can't increase the load because at 6.1g the case is just about full to the top.  The rifle has a JP recoil buffer, so I was thinking of removing the weights and trying it with just the spring.  Curious as to whether anyone has tried that.  My other option is a polymer buffer and a Nemo spring, so if the JP doesn't work, I guess I'll try that.

[Alaskapopo]

I use a JP competition buffer in my 300 blackout sub sonic with 150 grain loads.  It works. Don’t think trail boss Will but give it a try

[ltdmstr]

Yeah, I'm getting the impression it might not work.  If I get the spring/buffer light enough to eject the case, it may not be strong enough to strip the next round off the magazine and chamber it.  Guess I'll find out.  Do you happen to know which JP spring is the lightest?  The one that's on there now is yellow.  I might also try cutting that down or seeing if I can find a replacement that's lighter.

[Snausages32]

The white one is the lightest

[ltdmstr]

Thanks for the info.  Hoping to get to the range tomorrow or Thursday to check it out.