JP Gen 2 9mm silent captured spring buffer ... HELP

[shurt]

After reading some past posts,  it appears my JP system needs some tweaking?  

 

Yesterday I shot my first USPSA match with my PCC.  My rifle is a mix of several companies with a Lone Wolf lower,  Frontier Armory LRBO Upper,  CMC trigger,  11" barrel and JP bolt with a standard buffer / spring.  My rifle shot flawlessly all day long.  I had ordered the JP silent captured spring buffer 9mm AR standard weight Gen 2 but it did not make it to my mailbox before the match so I used the standard buffer / spring for rifle length.  Again,  it worked perfectly on Saturday for a 175 round match.  When I got home from the match,  my new JP buffer and spacer were on the porch. 

 

Today made the installation.  Remember,  two days ago this rifle worked like a charm but once I installed the spacer and new JP silent buffer system it will only fire one round,  eject, and cycle the next round with what appears to be a light primer strike.  It's turned my rifle into a single shot.   I tried factory rounds of 115,  and five different 147 gr reload configurations all of which worked perfectly a few days ago.  At one point,  my rifle went full auto for three rounds but then turned back into a single shot.  

 

Question:  Am I right in thinking the bolt is slamming so hard to the point it's knocking my bolt out of battery which is all caused by the new JP buffer?  Would my new captured spring buffer be to heavy?  Not heavy enough?  What is the fix if I want to use the JP silent buffer?  

 

Thanks

Scott 

[1911luvr]

Do you have a rifle length extension tube or carbine length? If it's carbine length remove the spacer because you're preloading the hell out of it. The spacer is for rifle length tubes.


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[shurt]

 

I have the rifle length tube.  

[Aircooled6racer]

Hello: The JP 9mm silent 9mm buffer uses a 308 extra power spring and the buffer weights twice as much as a regular carbine buffer. I am guessing you are using some reloads which will be loaded to a lower power factor than factory ammo which the standard JP setup is made for. You will need to lighten the spring and the weight of the JP silent buffer setup for lighter power factor ammo. Thanks, Eric

[CZ85Combat]

It sounds like you do not have enough bolt travel and the trigger is not resetting.   Check your tube and make sure that there is not a rubber bumper in the bottom.

[shurt]

Unfortunately there is no rubber in the bottom.  I want to use the JP silent buffer system but only if it will shoot my soft 147's and be reliable.  Using the standard buffer and spring the rifle was flawless.  I just think it would be nice to use the JP buffer system.   Guess I'll call JP tomorrow.  

[lumberjack149]

I don't know much on the JP SCS but your cmc trigger is not meant to be used in a pcc

[shurt]

UPDATE:    After calling JP and using all of their recommendations .... IT STILL WOULD NOT WORK.  I then used lumberjack149 post and changed the trigger and its works!  My CMC trigger is NOT meant to be used in a PCC.  Using the stock trigger,  the rifle is working fine!  

 

Thanks lumberjack149