458 SOCOM

[fa18hooker]

A cousin in Alaska asked me to build him a .458 SOCOM upper (think bears & such). I didn't have any experience with the cartridge, so I started researching. Pretty amazing: fit a .458, 250-500 grain bullet into an AR-15 platform...kind of like the .300 BLK on steroids. Heft investment in tooling, but the results are pretty impressive. I turned an 18.5" barrel and used the last 2.5" for a custom muzzle brake. There's very little shoulder on the cartridge, and the reamer flutes are large, so cutting the chamber was fairly easy. I reamed the gas hole very small to start, and ended up at 85 thou for reliable cycling without crushing the buffer. The only downside is ammo...commercial ammo is prohibitively expensive, and even just the components for rolling your own are up there (Barnes TSX projectiles are over a buck apiece, but there are cheaper options out there). The lightweight supersonic is impressive...accurate, and earth moving...throws divots like Tiger Woods. Now have to work up subsonic loads with some heavy bullets. If anyone knows a good source for .458 bullets, let me know! (.458 SOCOM with a 5.56 for comparison)

 

[PowPow]

Bonus here is that you have a standard capacity AR magazine that holds 10 rounds of .458 SOCOM. Same mags, way more boom. Want.

 

[vinjet700]

A decent source when in stock....

http://sbrammunition.com/458sl.html

 

[IndispensableDestiny]

Just look for bullets for the .45-70 Govt or .458 Winchester.

 

[Magnumite]

Youzzer, now that's appealing. I wonder if that is 'legal' for 3gun heavy metal class.

Ballistics investigation time.

 

[Marauder]

Some links for bullets. http://www.lehighdefense.com/
http://www.midwayusa.com/find?sortby=1&itemsperpage=20&newcategorydimensionid=20560
http://www.grafs.com/retail/catalog/category/categoryId/938?

 

[Afrikeber]

The battle experienced Special Operations community love this round. Most hit with it never get back up.

 

[iH8DemLibz]

How much milling work did you have to do to the width of the ejection port to create enough clearance for that fat case to eject properly?

 

[BradMacc82]

How much milling work did you have to do to the width of the ejection port to create enough clearance for that fat case to eject properly?

If he bought the stripped upper from Wilson Combat, none.

 

[iH8DemLibz]

If he bought the stripped upper from Wilson Combat, none.

The .458 is on my short list.

I would go the cheap and fun route and open the port up myself.

Next year.

 

[BradMacc82]

The .458 is on my short list.

I would go the cheap and fun route and open the port up myself.

Next year.

I had a tough time deciding, .458 or .50Beo - then Midway gave me a pretty nice birthday discount, and they had a .50Beo upper in stock - so that pretty much made my decision for me.

 

[Alea Jacta Est]

That's wicked nice

I had a tough time deciding, .458 or .50Beo - then Midway gave me a pretty nice birthday discount, and they had a .50Beo upper in stock - so that pretty much made my decision for me.

OoooocheeMama that's a good looking round. Just might do some damage.

 

[teratos]

OoooocheeMama that's a good looking round. Just might do some damage.

Brad gave me a dummy .50 Beowulf round. Impressive.

 

[BradMacc82]

OoooocheeMama that's a good looking round. Just might do some damage.

It's a lot of fun, the big bore AR's are always fun. Somewhat impractical? Possibly, but a lot of fun.

Brad gave me a dummy .50 Beowulf round. Impressive.

I've been leaving one with every IP I visit as well, still need to get one over to Mario at KeepShooting - they've done right by me.

 

[teratos]

It's a lot of fun, the big bore AR's are always fun. Somewhat impractical? Possibly, but a lot of fun. I've been leaving one with every IP I visit as well, still need to get one over to Mario at KeepShooting - they've done right by me.

Yeah. I fondle it every now and again. I have a lower destined to become a .50 Beowulf. I blame you, Brad. That means I'm going to need a .50 cal suppressor.......

 

[outrider58]

A cousin in Alaska asked me to build him a .458 SOCOM upper (think bears & such). I didn't have any experience with the cartridge, so I started researching. Pretty amazing: fit a .458, 250-500 grain bullet into an AR-15 platform...kind of like the .300 BLK on steroids. Heft investment in tooling, but the results are pretty impressive. I turned an 18.5" barrel and used the last 2.5" for a custom muzzle brake. There's very little shoulder on the cartridge, and the reamer flutes are large, so cutting the chamber was fairly easy. I reamed the gas hole very small to start, and ended up at 85 thou for reliable cycling without crushing the buffer. The only downside is ammo...commercial ammo is prohibitively expensive, and even just the components for rolling your own are up there (Barnes TSX projectiles are over a buck apiece, but there are cheaper options out there). The lightweight supersonic is impressive...accurate, and earth moving...throws divots like Tiger Woods. Now have to work up subsonic loads with some heavy bullets. If anyone knows a good source for .458 bullets, let me know! (.458 SOCOM with a 5.56 for comparison)

Damn you!

 

[BradMacc82]

Yeah. I fondle it every now and again. I have a lower destined to become a .50 Beowulf. I blame you, Brad. That means I'm going to need a .50 cal suppressor.......

Should I save those 530gr Steeltips for you then?


SCARCQB gave me a few links for .50 suppressors, one day, one day...

 

[fa18hooker]

The ejection port does have to be opened up, a little over 100 thousandths. The devil is in the details though: I opened up the bottom of the port, so the ejection port cover could still be used (closed). I was having ejection problems though, so I thought I'd have to open up the top too. Turns out the upper "ear" of the ejection port cover spring was sticking up into the ejection port, causing rounds to hang up. Toughest part of the whole project was opening up the bolt face to accept a .473 rim (the .458 has a rebated rim because there's no way you're getting a magnum bolt face onto an AR-15 bolt). Marauder, thanks for the link to Grafs...I ordered a few different kinds.

 

[BradMacc82]

I do apologize for the slight derail fa18.

Did learn something new, didn't realize it required that large of a bolt face - figured it used a rebated rim like the .50B (.447), interesting.

 

[BenL]

Should I save those 530gr Steeltips for you then?


SCARCQB gave me a few links for .50 suppressors, one day, one day...

A Bowers 50 Beowulf suppressor is on my "buy" list this year.

Umlaut Industries is about 25 minutes from my house and I played with one, there. Very nice and not too expensive ($750.)