Im rather new to the AR scene and I dont know a thing about tuning the AR. I guess I have been lucky (from what I read about Bushy so far) my rifle shoots true and have only had 3 mag induced failures (early on) bought new mags and all was well. If you could help me out with Buffer weights I know there are different ones but had no clue there were different gas port sizes. I thought gas port size depended on the barrel length to get the proper amount of needed gas to perform correctly but came from the factory pretty close .
I think of the AR as a vette runs great from the factory but always room for improvement
If you’re buying a complete LMT upper, you really shouldn’t need to mess with anything other than the buffer weight. I haven’t heard of any LMT’s with gas problems.
Adjusting the gas port size is something you should worry about when you cut down a longer barrel. A factory SBR upper should come with the gas port drilled correctly.
Not sure if tuning is a good term… It should be more like “Reliability Enhancements”
For my Bushy 14.5 I replaced the Bushmaster BCG with a complete unit from LMT. The LMT unit is MP inspected and the gas key is properly staked to the carrier.
I also replaced the standard carbine weighted buffer with an “H” weight buffer. This slows the action just a bit and helps the rounds feed off the mag better.
I was not having any issues but I made the changes anyway. Better safe then sorry.
LMT’s 10.5" uppers come with gas ports at the absolute small end of the spectrum.
If you are not running a can or using full power ammo, you may experience some short stroking in the beginning, especially with heavy buffers.
Start with a regular carbine buffer with an LMT 10.5" upper.
Keep the gun wet to mitigate short stroking while it breaks in.
If you want to consistently run wimpy ammo and don’t have a can or a KX3, I recommend opening up the gas port by one or two wire gauge sizes.
I have had to do this for a couple customers that purchased LMT 10.5’s from me.