Hey all, long time lurker first time poster.

About 80% through parts collection on my lightweight 300BO LBP build. Looking to get some advice on spring and buffer combinations to keep the BCG cycling smoothly with a BFS.

Will be using:
Buffer tube from Tailhook pistol brace
3 guns lab - Low mass BCG 5.9oz
Franklyn - BFSIII
BCM - 9" enchanced fluted 300BO

Want to get ideas and experience on spring and buffer weight for such a build.

Cheers

Are you using an adjustable gas block as well?? If so I really don't think you'll need the heavy buffer.

On my 10.5" gas driven build I use a standard weight buffer for supers and subs. The gun has its gas setup for subs 99% of the time as I use it as an HD gun with suppressor. Very soft shooting.

On my 9" piston build with light weight carrier I use a 1oz buffer and can adjust the piston gas to run with supers and subs. Runs like a top.

I have a non adjustable gas block to start, it happens to be color coded to my preference already.

I talked to Franklyn Armory and they suggest carbine spring and normal weight, with doubts I would need to go heavier.

Haven't been able to cycle yet, still waiting on all parts to come in.

Logic tells me the gun should cycle and lock back when empty just fine. But concerned about the BCG being slammed around with extra pressure and it being aluminum won't last long.

The whole point of a light weight, specially aluminum bolt carrier, is that you can turn the gas way down and still have the same bolt speed. If you are running a light weight carrier without an adjustable gas block you are going to have increased bolt speed and need an even heavier buffer which defeats the whole purpose of a fancy smancy  aluminum BCG.

I don't see the point in running such a light weight carrier but with a heavy buffer. I doubt the need of even a standard weight buffer unless shooting full auto. You could just replace all of you buffer weights with aluminum ones instead of paying 200-300$ for a LW carrier.

I worry about the durabitly of my alumium BCG even when im going to run an empty buffer and have my gas turned down to where it will barely lock back.

I did go ajustable block. And 3oz SMB weight.

It won't cycle subs at full gas but locks back on supers near full bleed.

I assume that's because the buffer is too heavy? I would like to be able to shoot subs too.

https://imageshack.com/a/img924/1204/Am0xNg.jpg