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

[A5BLASTER]

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.

Not to come off rude. But if your 0 for 3 on barrels not liking the 123 grain pills. Could it be the shooter and the loading practices being used?

[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.

[lazyengineer]

Not to come off rude. But if your 0 for 3 on barrels not liking the 123 grain pills. Could it be the shooter and the loading practices being used?

Absolutely! Which is why every variable imaginable has been adjusted, including ammunition. Amd firing style. The barrel likes 120s, my luck with 123 is still mixed. Could be me, but I have gold medals from Camp Perry with heavy recoiling 30-06, High Master and Distinguished Rifleman pins, so maybe not.

There are 100 variables to making something shoot right, so who knows. I've adjusted every one of them I can think of.

[lazyengineer]

Anyway, point isn't to bash - the barrel is heck of a barrel for a staggeringly good price; and the team purchase experience was quite pleasant.

Just for whatever reason, 123's and my kit don't seem to get along. Between my own experience, and the odd trend for some manufactures to seem to think short-throating the barrel is a good idea, I'm beginning to think 123's don't seem to throat jump so good. Blunt objective bullets like the 90's and 120's, seem to do better; which is consistent with bullets forgiving to throat-jump. In a semi-auto, there's not much one can do about that, other than buy a short-throat barrel, single load, or just don't use 123's if your particular barrel doesn't seem to run them.