120 SMK Vs 123 SMK....what is the difference?

[LRRPF52]

Well I guess that's part of my frustration. I was under the impression buying a Team BBL made by purists and of the appearance of defacto endorsed by the site; I figured that the chamber would be cut to whatever the proper chamber is supposed to be, on my TEAM Monster BBL. And so in line with the above, shoot the 123's well. It didn't work out that way for me. Are the TEAM BBL's not chambered correctly?

I know your own experiences with Grendel have been exceptional with accuracy. Mine have not. At all. The cost of cutting a correct chamber is no more than cutting an incorrect dimension chamber, and PSA usually does a decent job of doing their job. It didn't work out so good, if my 123 experience is the test. So I bought a team BBL, because surely that has the correct chamber. Again, it hates 123's. Is there something unusual or exotic on your BBL's that's not standard? I'm 0 for 3, on BBL's that are as modern and recent as you can get.

I have no control over what barrel you purchased.

I'm a moderator, not a barrel-maker or QC inspector over anything you have purchased.

All I can relate are my direct experiences with the barrels I have purchased, the accuracy procedures I personally use when building an AR15, and the fundamentals of marksmanship I apply when running a gas gun that has more recoil than .223 Remington (It's considerably different than free-recoiling a bolt gun.)

I have one of the Faxon 12" Grendel barrels that was a forum group buy, and several Lilja Group buy barrels from years ago.

This is how the 12" groups with me rapid-firing it using 123gr American Gunner:



Anther shooter with another 12" Faxon group buy with several different loads:



I haven't shot any of the longer group buy barrels that have been run recently.

I can only account for what I have in my hands and report exactly how it performs.