I just purchased a LMT complete lower to go with a complete 16" LMT upper that I had previously purchased. It is my understanding that the LMT lower comes with a standard carbine weight buffer (the buffer has no markings) and my complete LMT upper came with a LMT S/A BCG. Should I switch out the buffer for a H buffer and if so which one? What about the buffer spring, should I change it as well? I have also been looking at the Ion Bod M-16 BCM BCGs from Denny’s Guns (GTS). Should upgrade my LMT S/A BCG to the Ion Bod M-16 BCM BCG at the same time? Is all this just a wast of money and the stock items are all I need for a reliable goto AR? Thanks in advance for your responses.
I say don’t fix what aint broke, but I tend to be one that can’t leave well enough alone and end up fixing it til it is broke. 
If your rifle is running fine with the standard buffer, don’t worry about it. And I think the S/A BCG is fine too. LMT’s are usually GTG, and I assume that’s one reason you went with them. That said. If you have the money and are feelin froggy fix it til it’s broke! Just remember take off parts lead to new rifles!
-RD62
LMTs run a little smaller gas ports and will run fine on a CAR weight buffer. If you experience extraction problems while using the CAR buffer (very unlikely) then upgrade to a H buffer.
Thanks, I guess I will find some other accessory to spend my money on, like a DD Omega rail.
Good choice!
-RD62
sounds like we’re building the exact same thing.
16" LMT bought as complete upper/lower,bought the SA carrier before i knew better.
just added the Omega rail…
i went ahead and added the H-buffer though.
i figured it might be usefull,especially with the SA carrier…and it was only $20 or so.
reduced wear?
runs great,although it did before as well.
Hello everyone. First post here.
If LMT is using a smaller gas port will that have any effect on the chamber pressure?
BTW This is a great site! It has really opened up my eyes with all things concerning the M4. So much bad information out there and if is good to hear from people with first hand knowledge.
No. Gas port size has nothing to do with chamber pressure. Chamber pressure is regulated by the ammo and chamber size and how they work together.
gotm4,
Thanks. After I thought about it for a second it made sense. I was thinking about pressure being less on the gas key, which has nothing to do with chamber pressure. Brain fart.
I got this grom Gene Swanson in a email.
“I run H buffers in all of our rifles. From 10.5 up to the 16 inch. I also run a lot of full auto so the H buffer slows things down a bit.”
Gene Swanson
Technical Specialist
Lewis Machine and Tool Co.
1305 W 11th Street
Milan, IL 61264
PH:309-787-7151
FX: 309-787-7193
Thanks, If they run H Buffers in their carbines, then why do they sell the lowers with standard carbine buffers?