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Tackleberry41
06-04-2015, 08:27 AM
Was looking at the 458 socom, but brass is an issue in them. Google didn't come up with much on forming them from something else. One thread suggested 300win mag, but don't see how with the rim size so different. A friend says he knows somebody with one and uses 338 brass. Unfortunately big magnum brass really isn't much cheaper than just buying 458 brass.

Saw on wiki that it uses same rim diameter as 308. Can you form from that or do you need to buy 458 brass?

kencha
06-04-2015, 10:09 AM
It has a rebated rim. You're not going to safely blow out the head/web of a 308 to 458 Socom dimensions.

Starline says they expect to ship the end of June. I'd wait, unless you can find someone to sell you some to get you by until then.

Tackleberry41
06-04-2015, 04:45 PM
I was just contemplating a build, best to do such research before vs after.

CT-shooter777
06-04-2015, 05:03 PM
I was just contemplating a build, best to do such research before vs after.

Absolutely, anytime I considered buying or building an unusual caliber firearm, get your brass first or be sure of availability or reforming.

That's why as cool as the .50ae was in the early nineties, I choose a .44 D Eagle, because the .50 was new and could have done a "dodo" bird.
Quite possibly if the Mag Research D.E wasn't still so popular, the .50ae would be a historical footnote.

jmorris
06-04-2015, 05:30 PM
There is no parent case to the 458 socom so you can't form them from another round (unless you start over).

The only thing that the .308 diameter case head allows is sharing she'll plates with all of the other rounds that use the same diameter and you can fit that size in an AR bolt.

kencha
06-05-2015, 12:37 AM
I was just contemplating a build, best to do such research before vs after.

Good idea, I just read too much into it. I'd suggest building one even though you can't form brass from another.

You picked a good time to be considering it, with Starline's planned upcoming run of brass. Just place a decent sized brass order and get building :)

YMMV, of course, but I don't find myself shooting high volumes of 458 Socom. Don't get me wrong, I love it. It is just not a plinking round. That, combined with my relatively good luck with brass life means I still haven't touched over half of my original 1000 cases I bought in 2009.

Tackleberry41
06-05-2015, 08:17 AM
I don't figure it to be something you throw alot of ammo thru. But it is pretty close to a semi auto 45-70. Seems to me they keep trying to make stuff fit an existing weapon. 300 AAC works, mostly, now had they lengthened the action a little with a little more case capacity might have worked out better. Seems like the 458 socom should have been based on the longer AR10 action. Already has the bolt face, they could have simply necked up 308 cases to 458, 20 rds would have fit in a mag, vs trying to shoehorn it into the 223 action.

kencha
06-05-2015, 09:24 AM
From the outset, the 458 Socom was intended for the smaller AR15 platform. It wasn't a mistake, it was a feature.

Plus, necking up a 308 would mean blowing out the top half of the brass, and no shoulder (some consider a shouldered case superior to headspacing off of the mouth), etc. I imagine trying to form the brass from 308 would result in extremely thin necks, with poor neck tension in a semi-auto rifle (think setback-induced kabooms) or, at a minimum, a lot of split necks from enlarging it that much as well.

Worked out better, how? As I understand it, it worked out exactly as intended. If you want AR-10 based thumper, it sounds like a 45 Raptor would be right up your alley, or the 500 Phantom (same designer as the 458 Socom, but AR10-based).

I haven't looked into reforming brass for either of those, though. But I imagine it is a bit tougher than just necking up 308 brass, unfortunately.

ETA: even if you were thinking of cutting the 308WIN brass back similar to the 223-300BLK conversion, you're not going to be able to use a 458 bullet. SAAMI spec is only 0.4703 at the base. Maybe develop a 416 Tackleberry? (Still no shoulder, though.)

Tackleberry41
06-05-2015, 01:39 PM
The 416 tackleberry is the sort of thing I would do. I know you do want some sort of shoulder, uncomplicates alot of things in a semi auto. The 45/70 with that big rim is not something that would work well in a semi auto, wonder how the rimless 450 marlin would do, maybe shorten the case a little to use pointed bullets.

I just see to many trying to fit things inside the existing AR action. Compromise this and that so it will fit. When a new or different platform would work better.

dragon813gt
06-05-2015, 01:48 PM
Research the history of the 458 Socom. It was designed for a purpose and it does it very well. Proprietary cartridges drive reloaders nuts. But that doesn't matter to the military.

jmorris
06-05-2015, 05:31 PM
Seems to me they keep trying to make stuff fit an existing weapon. 300 AAC works, mostly, now had they lengthened the action a little with a little more case capacity might have worked out better.

No one in their right mind would want a "longer" 300 blk loaded into the larger AR10 when they can buy one in 308 ready to go.

Another problem you are going to create is how to form the longer brass, the 300 blk uses a .223 case cut just shy of the shoulder. Trying to expand up from .223 to 308 will result in more failures and shorter brass life.

Look at AR15's like the small block Chevy of the gun world, folks can hotrod what they already own. That is the appeal to most.


That at said the 458 socom brings a lot more energy to the game than the 300 can, still can't deliver more than my lever action 45-70 but you can't shoot 45-70 out of an AR. ;)

If if you want the best reason for "existing weapon" multi purpose, think SBR or machinegun. One receiver that can do the job of many rifles for the price of one stamp.

Artful
06-06-2015, 11:19 AM
http://www.loaddata.com/images/database/458%20SOCOM.gif

You could form your own .458 SOCOM brass; however it would be economically unwise. The only case that has the proper base diameter and rim diameter is the .425 Wesley Richards, which runs about $4 a piece.

Any other brass will not have the proper rim size, either too large or too small. In a pinch, you could form .458 SOCOM from .50 BeowulfTM but the rim would be smaller. (7.62x39 size rim - which you could change your bolt head to work with)

The initial prototype brass bore the .50AE head stamp and this has caused some confusion. The SOCOM case is 1.575" long, the .50AE is 1.290" so therefore, you CANNOT form the SOCOM case from the AE case because it will be short.

Or you can get 500 Linebaugh Long, 500 S&W or 50 Alaskan brass, form it, trim it, then turn down the rim on a lathe and cut an extractor groove.
http://www.loaddata.com/images/database/.500-S&W6.gif
You could do the same with something like Ruger 338 mag.
http://www.loaddata.com/images/database/.338%20Ruger%20Compact%20Mag.gif
but you will have 0.003 swelling on each side of the case when fired.

Much more effective to just purchase it.

Well, when it's in stock
http://www.midwayusa.com/product/941591224/starline-reloading-brass-458-socom

you could look at something like 450 Bushmaster which can be made from a number of cases like the .284 WCF but it uses
.452 boolits so you don't have the large selection of .458 molds.

dkf
06-06-2015, 03:12 PM
As said there is no parent case for .458 socom. Starline is the only company making brass for now. If the round ever gets SAAMI approved that may change. Meanwhile .458 brass is not that hard to find, I know of several places whom still have it. Starline makes runs

Only case forming of .458socom I know of is the rimmed version for Encores and similar firearms. You make .458socom rimmed brass from .50 Alaskan brass which is easy to do.

Tackleberry41
06-08-2015, 11:18 AM
I tend to buy proper brass, but always good to know how to make some in a pinch. Doubt will have the cash for any kind of build anytime soon anyways.

FLYCUTTER
06-08-2015, 03:04 PM
Why do all that work . Just buy a 50 Beowulf or build one. The brass is cheaper than a Socom and there is a variety of bullets to pick from and it all goes on top of a AR lower.

Tackleberry41
06-08-2015, 03:14 PM
One reason to go with 458 is I already load for 45-70 so have several molds. Beowolf I would start from scratch. Your sort of restricted to pistol style bullets with the Beowolf vs the 458. Pretty sure they both fit on top of an AR, I don't have one so it would be a complete build.

jmorris
06-08-2015, 10:49 PM
They both fit on top of a standard AR lower the 458 will even work with stock GI mags, although they become single stack because of the width of he round.

W.R.Buchanan
06-09-2015, 02:58 PM
The 416 tackleberry is the sort of thing I would do. I know you do want some sort of shoulder, uncomplicates alot of things in a semi auto. The 45/70 with that big rim is not something that would work well in a semi auto, wonder how the rimless 450 marlin would do, maybe shorten the case a little to use pointed bullets.

.450 Marlin is a belted case, it is not rimless.

Randy

jdl6mm
03-01-2017, 08:47 PM
Tackleberry41 you can't neck a .308 to .458 to begin with. Next, the ar15 was made for the 5.56. So there is no reason to lengthen it. If it was longer, it wouldn't be the ar15.

Sent from my VS987 using Tapatalk

Smoke4320
03-01-2017, 10:17 PM
Jewdish searching you can do d 458 socom cases for 65-75 cents a case
Don't rush just keep looking it will appear from time to time

dkf
03-01-2017, 10:33 PM
I'm buying Starline for $.68 each with shipping. Not uncommon to get 20 loads out of a piece of brass.

rockrat
03-02-2017, 01:27 AM
I shoot a 30-223. Easy going from 22 to 30 cal. Might lose 5 cases per 100. Anneal and go shooting