I'm in need of some experienced advice. After deciding to build my dream 308 semi instead of buying Larue predatobr ( may regret later) I need some advice on my last piece- BCG..I'm going top of the line on everything I can and have already ordered a JP Lo mass complete BCG, but after some more reading, it seems to be more of a precision fine tuned competition bolt than a "go bang every time" bcg. My question is stick with JP or go to a straight DPMS BGC for the reliability due to the heavier profile. One thing- I plan to run it suppressed and want a more military/ police sniper style than a bench/ completion gun. Here is a parts list of what I have so far:

New Megalithic upper lower combo
Mega Arms Match 16" barrel ( DPMS extension)
Syrac Gen 2 adjustable gas block
Choose ( have both) JP 308 carbine silent captured Spring or DPMS buffer and JP 308 carbine spring
BCM lower Parts Kit
Geissele 2 stage trigger
Standard adjustable carbine style tube

Is it worth an extra $350 to go with the JP bolt and Silent Capture Spring? I don't mind paying as long as it's truly a better solution for my needs. Thanks in advance.

I really don't think any problems you encounter will be the fault of a JP bolt and carrier.  They will be just as or more reliable that the best of the other options.

Captured spring is up to you I think.  It works well, but is a large cost for gains that are difficult to quantify in my opinion, other than weight.  My reciprocating mass weighs nearly 2 pounds and with the JP parts you could trim that some- at much higher cost.

Your adjustable gas block will help you run efficiently with pretty much any of your options at this point, quit thinking about it and just shoot.  This coming from a guy that frequently suffers from 'analysis paralysis'.

Thanks man.

You can get a complete LMT MWS bcg. That's pretty to of the line, dual extractor, hard chrome I think,,might be nickel coated. But I think that would be a more reliable option.

But with an adjustable gas block, that's where the JP bcg will shine.

I love my jp bcg but I think a regular buffer and spring is sufficient

I too went "all out" on my 308 AR with Rainier billet receiver set and Fortis SWITCH hand guard.  I am running the JP Silent Capture Spring, 16" Mega barrel, but I am using a AIM NiB BCG.  I just didn't see the need to spend a lot of money on a fancy BCG that ultimately will do the same thing as every other BCG.  That said, I have thought about going with the JP light weight BCG and an adjustable gas block to see if I can further reduce the felt recoil.  It doesn't kick too bad though the JP spring and a flash hider.  So if I spend $$$ on a BCG, it would be the JP that you are looking at.  I would not spend a lot of $$$ on a regular BCG like WMD or something, I just don't see the value for the amount of money over something like the AIM NiB BCG.  It has functioned flawlessly in mine so far and I don't expect to have any issues out of it.

Bought both. I will test out each and save one for a later build.  The JP should be very sweet once it's tuned properly. I just don't shoot the same kind of ammo all of the time..