Options for a 458 SOCOM build

[Arizona_Mike]

I'm thinking about building a 458 SOCOM upper.

I really want a muzzle thread that will allow be to use my TiRant 45 silencer (with subsonic loads only of course). I think 5/8-24 is probably my only option which leaves with with Tromix or SBR barrels (Wilson uses 11/16-24 and RRA uses 5/8-32). Tromix uses a pretty non-standard .875 dia at the gas block which limits my choices of an adjustable block (I want a restriction type not bleed type like Superlative Arms)--I'll probably end up going with the SBR Cromoly despite my preference for stainless to get that muzzle thread and a standard .936" dia at the gas port.

Is it best to buy a 458 upper receiver or should I enlarge the port myself (or have it done)? If so, which brand? Which brand of bolt?

Any things to look out for that may be different than my 5.56,Wylde,300BLK, and 9mm builds so far? Feed ramp modifications/blending, etc?

Thanks, Mike

 

[Sheepdog1968]

I think Wilson Combat sells a complete upper as well as mags optimized for 458. Problem cost a bit more but probably run very well.

 

[Arizona_Mike]

I think Wilson Combat sells a complete upper as well as mags optimized for 458. Problem cost a bit more but probably run very well.

Their modified Lancer mags look like an excellent choice and I may go with them but I do not want propitiatory 11/16-24 muzzle threads.

I enjoy building uppers and lowers, btw.

Mike

 

[arizona_cards_11]

I was in the same position as you a couple years ago and ended up just going with the Tromix upper and 8" barrel/bolt combo, after having owned a Wilson 458 upper.

No complaints really -- the quality is suitable for the price and the amount that I actually shoot a 458 socom. I haven't had any reliability issues to speak of.....but I've only put ~150 rounds down range, so take that for what it's worth.

 

[jmorris]

I have the RRA 458 upper, has always ran like a top. I use regular old colt 20 round mags.

I built my own suppressor and threaded it 5/8-32 to match the barrel but if your going to SBR it, once you cut the barrel, thread it whatever you want.

 

[Arizona_Mike]

Tromix can do stainless. I'll just have to research my gas block choices carefully.

Mike

 

[Arizona_Mike]

After learning yesterday that Superlative actually made the gas blocks for Syrac (now out of business) I did some follow-up and it seems that Superlative blocks can be used in both restriction and bleed modes. Apparently fully closed to about 4-5 turns out they are restrictive, then there are a few clicks at full open, and if you keep turning the screw out to as many as 8 turns they use bleed off.

Can anyone who has one verify that behavior?

It seems the superlatives are available in both .875" and .936".

I'm actually delaying my .458 SOCOM build and will do a 204 Ruger build next.

I'm watching .375 SOCOM developments closely. Seems to be an amazing cartridge with just over 1/3 the drop at 300yds and gives .30-06 energies in the 200-235gr range. Apparently proper bullets are the big issue. .375 Win bullets are grenading in hogs and their thin jackets are not tough enough for semi-auto function and deformed bullets are leading to a 2 MOA accuracy limit. Some folks are claiming 1/2 MOA dropping cartridges straight into the chamber.

Mike