I'm building a 458 socom upper, mid or carbine length gas system?

[gnostic]

I'm building a 458 socom upper with a 1:14, 16" barrel with brake and adjustable JP gas block. When ordering a barrel, should I order a mid, or carbine length gas system? The 458 is a low pressure round and reliability could be an issue mid length and the shorter carbine system might shred my very expensive brass. My only AR 15 is a mid length, M-4ish 5.56 and it's easy on my brass, compared to my mini 14 and 30. It would be good if the 458 socom was easy on the brass as a case costs close to a buck...

[DDriller]

Carbine is all you need. If you haven't bought your barrel buy one from Tromix along with his bolt. He made the first 458 socom and his prices are good.

[DCM]

The carbine length gas system functions well IME.

[Meatpuppet]

I went down he road of building my own upper with an adjustable gas block and a bunch of expensive internals. Took a long time to get it to function right. I finally bought a complete Tromix upper and it ran great from day one. Now I have my home-built upper dedicated to heavy, suppressed, subsonic rounds and my Tromix for everything else.

If I had it to do over, I would have just done a Tromix upper build and saved a bunch of money and time getting it right.

But the "journey" was educational and fun.....

[gnostic]

Thanks for the response, I've been to Tromix's website and might buy the barrel and bolt from them. I probably would have come out ahead buying a whole upper from Tromix, had I not already started picking up bits. Carbine length gas system is what I'll buy, thanks again...

[jungleman9941]

Cant go wrong with tromix

[frkelly74]

Mid South has 450 bushmaster and 458 Socom uppers complete for $400.

[M-Tecs]

I have the same question. In the .556 I don't recommend a carbine length gas system. On my match rifles I extend the rifle length gas system 2". I have zero experience with the 458 SOCOM but everything I have read states the carbine length gas system is the way to go with the 458 SOCOM.

[RangerDan]

My 458 SOCOM has mid length gas system and I shoot many 300 grain cast bullets through it with no problems in function or brass.

[popper]

My understanding it's the length of barrel after the port - too short and pressure is lost when the boolit exits. With the adj. block you can tune extraction rate/timing which is what damages brass rims.

[Tackleberry41]

450 runs lower pressure than the 5.56. So while carbine length is overgased in 5.56, works great in 450. Most barrels I have seen for sale are carbine length system.

Mine runs fine as is w carbine system, standard gas block. But a really heavy buffer tamed the recoil alot. I see everybody w carbine stocks on 450s. I prefer the rifle stock and heavier buffer. Can get alot more weight in a rifle buffer than carbine.