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Build Thread Building 458 socom

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I want to build an AR 15 in 458 socom. I am considering an SBR, for purpose of taking it in back-county scouting / hiking / backpacking. What barrel length / twist works well for this cartridge?
Or are there other BIG BORE AR15 cartridges would be better for a short barrel. (Looking for something bigger than 300 AAC).
 

DirectDrive

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I want to build an AR 15 in 458 socom. I am considering an SBR, for purpose of taking it in back-county scouting / hiking / backpacking. What barrel length / twist works well for this cartridge?
Or are there other BIG BORE AR15 cartridges would be better for a short barrel. (Looking for something bigger than 300 AAC).
The guy that developed the 458 SOCOM has a FAQ list on his site.
I think you may find the answers to your questions there...
Teppo Jutsu : Advanced Firearms Applications

ETA:
I like the 458 SOCOM over the 50 Beo and 450 Bush because the 458 is built like a rifle cartridge, headspacing on the shoulder.
It also runs in 5.56 mags without modification.
Use USGI mags or Lancer mags for best results.

A-9.jpg
 
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What barrel length / twist works well for this cartridge?
Or are there other BIG BORE AR15 cartridges would be better for a short barrel. (Looking for something bigger than 300 AAC).
Tromix sells 10.5" and 12" barrels, sounds like 10.5" is the better seller. That is probably what I'd go with on an SBR/pistol build. I'm going the 16" carbine route myself.

I think it is the best of the big bores, that's easy, I still can't up my mind on 6.8 SPC vs 6.5 Grendel vs .277 Wolverine. :confused:
 

scarlo

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Tromix also has the .375 SOCOM. Check out The Big Shooterist Ish's Tactical Solutions on YouTube for more on big bores. Another to look at is the .338 Spectre available at SBR Ammunition.
 

DirectDrive

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I had read that the 458 takes a lower that is built for it (strength, I assume). Is that a real consideration?
No, that's bad information.
Go back and read the FAQ that is in post #2
Marty put that together so folks would get the correct information about his cartridge.
 
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Good more people buy them so it becomes more prevalent and the price drops. Every time I had the .458 thought I looked at it compared to preexisting calibers and couldn’t justify the additional ammo cost.

Seems cool though.
 
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I still can't up my mind on 6.8 SPC vs 6.5 Grendel vs .277 Wolverine. :confused:
6.8SPC vs 6.5 Grendel is a tough one.
.277 wolverine I wouldn't even consider until there is more barrels and factory ammo available.

That alone makes 6.8 vs 6.5 interesting... 6.5 has tons of barrel support but factory ammo options while out there are seemingly more sparse/limited at the moment and sells out quickly when cheaper quality ammo is available. More expensive ammo @ $1/rd+ is however almost always available.

6.8SPC II on the other hand has less barrel options available out there than grendel, but more factory ammo choices for under $1/rd readily available. seems to be some PPU and S&B ammo out there both between $0.55-$0.70/rd as well as hornady black at right about the same cost/rd as the grendel.

A year or two ago the ammo availability wasn't as good for SPC and it wasn't getting a good rep... but with 6.8SPC II the issues have been seemingly fixed and its performing quite well. possibly even better than grendel for as cheap or cheaper. If you can get a good deal on a barrel, BCG, and magazines...might not be a bad round.
 
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The thing about the the .277 WLV is only a barrel change is needed, same BCG, same mags. That's a biggin'.
Still...very limited barrel options, and as far as I can tell..nobody makes factory ammo for it at all. It's basically a niche caliber for re-loaders only.

With 6.8 spc you do share a bolt with .224 valkyrie, so if you jumped on that bandwagon at all then same bolt/mag should work there.

I have a grendel. While my bolts aren't shared, my 7.62x39 mags are shared with my grendel.

Honestly though the wolverine is a failed round IMO... it was designed 5 years ago and hasn't caught traction at all vs .224 valkyrie (as a comparison of a successful round in a similar short time frame as both the 6.8 SPC and the 6.5 grendel had 10-15+ years to mature) was designed only 3 years ago and it quickly spread like wildfire... factory loaded ammo available all over, and aftermarket barrels and uppers available all over... Kinda what I was getting at with the .277 vs 6.8 vs 6.5 and why I wouldn't even consider .277.
 
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Still...very limited barrel options, and as far as I can tell..nobody makes factory ammo for it at all. It's basically a niche caliber for re-loaders only.

With 6.8 spc you do share a bolt with .224 valkyrie, so if you jumped on that bandwagon at all then same bolt/mag should work there.

I have a grendel. While my bolts aren't shared, my 7.62x39 mags are shared with my grendel.

Honestly though the wolverine is a failed round IMO... it was designed 5 years ago and hasn't caught traction at all vs .224 valkyrie (as a comparison of a successful round in a similar short time frame as both the 6.8 SPC and the 6.5 grendel had 10-15+ years to mature) was designed only 3 years ago and it quickly spread like wildfire... factory loaded ammo available all over, and aftermarket barrels and uppers available all over... Kinda what I was getting at with the .277 vs 6.8 vs 6.5 and why I wouldn't even consider .277.
We'll see, it has expanded to the bolt gun...
277 Wolverine - Std - Magnum Contour - 24" - Matte SS - McGowen Precision Barrels

The Valkyrie doesn't really interest me, I'll stick with .223/5.56 77gr OTM for slinging long range 22 caliber pills, beyond that I'll jump up in caliber and payload.

What I'd really like to see take off is the 6.5 MPC, but I'll probably end up with the Grendel, I'm in no hurry.
 
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I have no interest in the valkyrie either. just used it as an example of a successful round developed 3 years ago and already full scale mass production of factory loaded ammo and barrels from multiple manufactures vs what seems to be a complete failure of a round. Wolverine was developed 5 years ago, yet nobody makes factory ammo for .277 wolverine. only a few barrels available from what 2 or 3 manufacturers?...big red flags to me to steer clear of it.


As for OP and his thread we totally derailed LOL (sorry! :oops:) 458 is a decent round but I hope you reload cause it's definitely not a cheap round. .450 bushmaster is a lot cheaper on ammo and decent ballistics. but still a round you would want to reload cause it still costs over $1/rd

Is there a reason you are dead set on larger than 30 caliber?
 

Twodogs

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I would like to build one with a 10.5" barrel, already have a sbr lower and suppressor.
 
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One of the guys I work with is building a 458, I'll chime in after I shoot it :)

I'm in the middle of a 6.5 build, should be done next month.
 

osprey

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I built one with a Tromix 16.25” barrel and matched bolt, it has been flawless. It is 1-14 twist will stabilize up to 500gr bullets at subsonic speeds and is a good overall twist choice. In barrels shorter than 12”, Tony recommends a 1-10 twist to stabilize heavy bullets at subsonic speeds. If you don’t care about subs the 1-14 is fine.
 
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