.458 Awesome

[Nolo]

I was thinking about .458 SOCOM (with it's impressive 3000 ft-lbs energy) when I had an idea. Whether that idea has any merit or not is debatable. Anyway, for those of you with QuickLoad (darn my stunted cashflow!), what would it take case-wise to send a 500-grain .458 caliber bullet at 2000 feet per second? I was kinda thinking of a design along the same lines as .458 SOCOM, only larger and faster and built for G3 (or other .308 battle rifles)-styles rifles.
Mostly just my musings, I do this a lot.

 

[GunTech]

Try 2000 ft-lbs for the 458 SOCOM. PMAX is only 35,000 PSI. It was originally designed to throw heavy bullets at subsonic velocities. Corbon has a 300gn JHP that will generate 2400 ft-lbs.

458 500gn bullet at 2000 fps? I do it with my 458 win mag all the time. 500gn monolithic over 72gns of W748. It's not a round you'll enjoy shooting. My 458 weighs 10 pounds and it will still beat the crap out of you with 500gn solids. If you want to know what it feels like, wrap a piece of thin foam over a baseball bat, and have a friend hit you in the shoulder.

 

[Nolo]

Ha. 2000 ft-lbs is most certainly not what was advertised. Why in the world would you lessen your magazine capacity (to a third), increase your weight and limit your ranged performance all for 700 ft-lbs? Just use .308 Winchester instead. Sheesh.

 

[SaMx]

because .308 winchester won't fit in an ar-15.

 

[Kimber1911_06238]

neither will a .458 socom...the ar has to be modified (different upper). The ar 10 does fit a .308, which is in my opinion a much better option.

 

[Car Knocker]

Hmmm. Corbon lists energy figures ranging from 2405 ft/pounds for the 300 gr JHP, 2249 ft/pounds for the 450 gr RN, down to 1203 ft/pounds for the 600 gr JSP. What ammo maker is advertising 3,000 ft/pounds?

 

[Cougfan2]

because .308 winchester won't fit in an ar-15

Try telling that to the fine folks at Panther arms just to name one.

 

[Car Knocker]

Try telling that to the fine folks at Panther arms just to name one.

The .308 marketed by DPMS/Panther Arms, and others, is not an AR-15. It is an enlarged model to handle the larger size .308 cartridge and relatively few internal parts, other than the trigger group, is interchangeable with the AR-15.

 

[HorseSoldier]

because .308 winchester won't fit in an ar-15.

neither will a .458 socom...the ar has to be modified (different upper).

458 Socom (wish USSOCOM got some sort of royalty check for all the "SOCOM" branded stuff out there . . .) will run through an AR lower, and the lower is the firearm as far as the BATFE is concerned. A big-bore AR upper is just mail order, no paperwork hassles or whatever.

 

[browningguy]

Firstly to answer the question, you don't want to try to get a .458 Socom up to 2000 FPS with a 500 gr. load, that's up in .458 Win Mag range and would put a serious hurtin' on you. I shoot my .458 Winnie pretty regularly and hunt with it every year. It weighs 10.5 pound unloaded, has a well designed stock, and still let's you know what it is. Mine has a 24" tube so I get around 2100 FPS with a standard 500 gr. load, but most 20-22" guns will get around 2050 with factory loads.

I also have a .50 Beowulf upper for my AR which I shoot a lot using mostly the 325 gr. JHP loads, the 400 grain loads I have shot average 1835 FPS and even that is pretty decent recoil in an AR. Both the .458 Socom and .50 Beowulf fit in a regular AR, they just enlarge the ejection pot a little to ensure good ejection and use a bolt that fits the case diameter. In the case of the .50 B thats the same bolt as a 7.62x39 AR. The .308 takes an AR10 size action.

 

[GunTech]

To answer the question about the 458 SOCOM, it was designed originally for subsonic loads. A 500 grain bullet at 1050 fps does a fair amount od damage. A 308 subsonic doesn't come close. The 458 SOCOM was designed to used in a suppressed AR and so the maximom amount of damage possible with that platform. 458 SOCOM also headspaces off the shoulder, and is superior for that reason to rounds like the 499 LW and 500 Beowolf.


458 SOCOM muzzle energy: 1224 ft-lbs (subsonic)
308 subsonic: 490 ft-lbs

 

[rero360]

so out of all the big bores out there that are availible in the AR platform (15, not 10) which is the best in terms of availibility of ammo, ballistics and the such.

 

[browningguy]

458 SOCOM also headspaces off the shoulder, and is superior for that reason to rounds like the 499 LW and 500 Beowolf.

Please remember, that's an opinion, not a fact.

As to availability, although I personally prefer the .50 B., the .458 Socom is more popular and has many suppliers of uppers (RRA for example) and ammo from other sources than the inventor, and so I would recommend it. Personally I think it was unwise of Alexander not to make this a SAMMI spec design, but he invented it so can keep it proprietary if he wants, just limits the market. Don't get me wrong, they make a good upper and I love my .50, and good ammo. But the number of license holders is small and their uppers are expensive, also no one but Alexander can make the ammo as he has not licensed it. So if shooting factory ammo you don't have any competition, hence the price stays up.

 

[GunTech]

Re: head space off the shoulder versus case mouth.

Why one is superior to the other? Headspacing of the shoulder allows for less precision in ammunition manufacture and make any crimping unimportant to proper feeding. Also case length is far less critical.

You will note that in most rifle cases that lack a well defined shoulder, a belt is used for head spacing because headspacing off the case mouth is less reliable.

YMMV

 

[SaMx]

Try telling that to the fine folks at Panther arms just to name one.

that's an AR-10