Any advice on a 458 SOCOM upper?
 

Trying to build an accurate 458 SOCOM. This will eventually be suppressed shooting subsonic loads for hunting Pigs at night, and supersonic loads for deer.

I got an inexpensive (not cheap) Aero Precision lower, now I'm looking for a good quality upper. Reviews on all the inexpensive ones have made me think I need to spend about twice as much as planned to get a good one.

Right now the two most viable options are Rock River and Tromix. Building my own with high quality parts seems to be more expensive than buying a Rock River upper. From reviews it seems Aero used to make a great 458 SOCOM upper that wasn't too expensive, but they no longer make them.

I got nothing but can't wait to see how it turns out!!

Already got the 410 grain SubX bullets. Dies and brass came in today. Mags should be here in the next couple of days, and the lower should be arriving at the gunshop by the end of the week.

Moving fast...

All useless as tits on a boar hog without an upper...:rolleyes:

GLFA was one of the better, but they seem to have quit playing.

Here are a couple of review sights.

https://www.americanfirearms.org/best-458-socom-uppers/

https://www.minutemanreview.com/best-458-socom-uppers/

If this is your 1st. foray into long stroke AR's I would recommend doing a complete upper. That way you're not in piece part fitment hell.

The gunshop owner I've been talking to about ordering the 458 SOCOM upper, got one in for me to try. "Omega Guns" is the manufacturer (or just the people who put the parts together.)
Their web site was down and I searched but could not find anything about them.

He said take it home and try it, so I did.

After sighting in at 15 yards, the first three rounds at 100 yards went into a 1.2" group.

I wish I could find out more information about the company, but I decided to take a chance on the upper.

That’s odd that you couldn’t find anything about them, but if it continues to perform well; I’d be happy.
You LGS owner sounds like a great guy, too!

As far as an unknown brand; I’ve always been a bit of a gun-brand snob, myself.
Then, a guy at a LGS I was just killing time at handed me a Canik pistol to try. Dry firing; the trigger pull was very good, and the reset was the best I’d ever seen! I bought the pistol the next day, and it’s become my #1 range gun; replacing a Wilson Combat that cost five times as much. I also carry it some, and the experience has me looking at less expensive guns in a whole new light.

Could be the same with your “newly discovered” AR brand.

I have a question for you AR gurus.
I have a milspec buttstock with the fixed sling swivel and a webbing slot.
How can I put a QD mount on there? Is there one that can replace the fixed sling swivel or that attaches to the webbing slot?

Good question. I don't use QD mounts on the buttstock only on the foregrip.
Here's what I found. Hope this helps.
https://midwestindustriesinc.com/qui...-car-m4-stock/
https://midwestindustriesinc.com/qd-...ion-car-stock/
I've used Midwest Industries products in the past. They're good quality.

Thanks!

I think for now I'm going to just use the QD for the front, using an M-LOK QD swivel, and clip onto the stock sling swivel on the buttstock, and worry about the rear QD swivel later.

I ordered this sling from Amazon:
https://i.imgur.com/eeFcHG6.jpg

So I would assume you are looking for the sling plate that goes under the buffer tube nut.
https://bravocompanyusa.com/bcmgunfighter-qd-end-plate/

https://phase5wsi.com/sloped-quick-d...te-sqd-ep.html

Left / Right 2 point

https://www.amazon.com/Lytoybe-Adapt...4793480&sr=8-4

So I've been playing with a few types for a while now. My BIL Mr.3 gun was having some issues with slinging and setup too. Some buds in TAC CQB squad turned me on to these; VTAC 2 point quick release. One pull draw and release to set and one pull deploy. Pretty nifty rig and easy to setup.

https://www.vikingtactics.com/category-s/1833.htm

Very good sling and company. They were the innovators of two point slings.
I'm a big fan of Magpul slings. I have MS1's on my rifles.
https://magpul.com/firearm-accessori...gs/slings.html

https://i.imgur.com/I68Mvi2.jpg
https://i.imgur.com/kSb0bvv.jpg

I'd like to keep it simple. Ideally, I'd just install a QD receiver in a port made for it, like many stocks have (but mine doesn't) but since it doesn't, I like something on the order of a QD receiver that either attaches to the webbing slot or replaces the fixed sling swivel. Attaching it to the buffer tube or receiver doesn't work for me. Too far forward. (butt would stick up too far making it difficult to climb into deer stands)

https://i.imgur.com/5i54Geo.jpg

If I could just wave my magic wand, I could make one of these appear on my stock. But unfortunately my magic wand is broken.:(
https://i.imgur.com/0HgTWXF.jpg
https://i.imgur.com/HpgLMIW.jpg

I understand.
I moved to the tube ring as it is a fixed point on the rifle and doesn't affect the sitting point when slung. Using the stock inherently gives you a moving reference. Besides my stubby AR's have folding stocks...

I think what I am going to do is just drill two holes somewhere below the webbing slot, and bolt one of the M-LOK QD swivels on. Probably need to cut a steel plate to go on the opposite side so I don't pull through the thin plastic.

https://i.imgur.com/pZYgNp3.jpg

Doc
Of course if you are frugal (my 31 yo daughter calls it cheap) like me you can rig a ring using the available stock hardware and paracord. I rigged a QD at the rear of the receiver but with a full length A2 Rifle stock it rode too high beating my face and jaws up in a 2 point sling. Understand I am 6'4" 250# with a giraffe neck so an A2 stock for everything but two point slung is perfect. So I rigged a ring on the off side using paracord, the installed sling loop and a snap hook. Works fine. I have a photo but can't post it here. PM with an email or text number and I can send it.
Hal

Yes, I have been pondering similar such solutions. I just need some sort of ring on the side. The fixed swivel at the bottom won't let me carry the way I want to and need something higher up.

Here's a novel thought...Maybe I can just use the webbing slot as a webbing slot! LOL It's in the right position. Put some kind of strap through there that wraps around the upper part of the buttstock, and has a loop on the end that I can clip to.

Your local tractor supply has brass and nickle plated rings that work well with an HK clip, like you showed on the sling up above. That is how I have one of my "carbines" rigged with paracord on the A2 stock. Even easier with the web slot. Paracord is easy to tie off and secure....webbing MEH.

The 458 SOCOM hog gun is almost finished. Almost as in one more thing to get, a silencer, which may take a while.

Here is the semi-final build.
Limbsaver snap-on recoil pad, Aero Precision Lower, UU&T night vision monocular attached to Leupold classic 3-9x40 (inherited from my father!), Ludex brass catcher (gotta hang to that expensive brass!), Omega Arms upper.

https://i.imgur.com/3dOd804.jpg

Damn son that is awesome. At first glance I thought you put a RPG launcher on the top funny

Can't wait to hear how it shoots....

So whats your barrel thread pitch 5/8-24 or .578×28(45acp)?
you could always try the oil filter adapter game til you properly certed (mugged) and get the real thing...

Looks like you got your sling mount figured out.

Believe it or not, I do not know what the thread pitch is. I will have to remove the flash suppressor to find out. The dealer didn't know, and the web site for the manufacturer isn't working right now.
The sling is just temporary. Clipping onto the fixed sling swivel on the butt doesn't really work for how I want to carry the rifle up a ladder into a deer stand, but deer season is over so no hurry on that. I have found a QD mount that attaches to the webbing slot but they are out of stock.

So if you wanted to mount the QD on a little more open space of the panel you could use one of these.

https://monstrumtactical.com/m-lok-s...-sling-swivel/

Yeah, that's what I was talking about. It's in the picture, along with a simulation of two holes I could drill holes to bolt it on.

I got nothing, looking forward to seeing this build, but that expression just had me rolling on the floor!!!

Hi Doctor,

I've read some reviews about that Ludox unit you have installed. I was considering one, except it has a piece that has to be "adhesived" to the side of the rifle. Did you use that double side tape? IF so... I was thinking about using a product called "Alien tape". It is non marring and completely removable. Let us know if you try it. Seems like a good alternative, especially if you want to use the ludox on several rifles. What do you think?

The piece has adhesive already on it, and once it sets, it's pretty solid. It comes with several spare adhesive strips and a tool for removing it, but you could use regular double sided tape.
You can buy extra bases on Amazon if you want to move it between several lowers.
I have not been to the range with it, but I don't see how it can not work. It's more compact than the netting type catchers and not obtrusive.

I guess it is waaaaay past time for an update on this.
Since neither Hornady nor Hodgdon was much help on load development (at least Hodgdon tried) it has taken many months to come up with a load that meets my design criteria. Complicating things is the fact that I let my range membership lapse, so I have to drive an hour to a public range, or wait until I get to my land to test the loads.

First to answer the question about the Ludex brass catcher after using it a few times...IT WORKS GREAT!

I am shooting Hornady 410 grain SubX bullets, ostensibly designed for subsonic loads. However Hornady acts like they don't know that it is for subsonic loads and would only say that there aren't any suitable powders.

I've been running simulated loads with QuickLoad and with Gordon's Reloading Tool, but for a while the real world results bore no resemblance to the simulations. I finally figured out how to tweak the parameters of Gordon's to make my actual velocity match the simulated velocity, and it came down to three candidate powders.

But before I go any farther, let me list my design criteria:

1080 fps muzzle velocity
Comfortable margin of error on max pressure. (35K is max for the SOCOM)
<=3000 PSI muzzle pressure
Enough port pressure to reliably work the action.
>75% Load density
100% burned powder (preferably before it reaches the gas port)
Easily obtainable powder, or powder that I already have
Under 2 MOA

The final three powders were CFE BLK, IMR 4227, and H110. After firing a load with each that I knew was a bit higher than my goal velocity, CFE BLK came out on top with an honorable mention to IMR 4227.
One thing IMR 4227 has going for it is that I have a lot of it. But unfortunately, after inspecting the bore after shooting the 4227 load, I could see some unburned powder kernels. Not a lot, but some.
In my earlier loads I had a LOT of unburned powder, which got into the action. Also, since this is intended to be a suppressed load, I don't want unburned powder going into the suppressor.

Here is the Gordon's simulation for the final load. The semi final load had a velocity of 1111 fps, so it only took a small tweak. >90% of the powder is burned before the bullet reaches the gas port. 100% of the powder is burned at less than 10". I have five rounds loaded up with this final load, and I'm just waiting to get to the range to confirm it and see what kind of accuracy it has.
https://i.imgur.com/WbpEhVF.png

Update on the SOCOM...

I have a subsonic load with the 410 grain SubX bullet that works. Hodgdon's CFE BLK powder was the magic powder.
And I also have a deer load with the 325 gr FTX that works, using LT-30 Powder that's running about 1550 FPS.
I tried using 300 gr HP bullets but the tip catches on the feed ramp on most mags. It still chambers, but with the tip distorted the accuracy suffers.

Speaking of mags...
30 round 5.56 PMag - I found that crimped, it feeds fine out of an unmodified mag, except for the 300 gr HP.
Uncrimped, the mouth catches on the front wall of the mag. But if I dremel a bevel on the inside of the front wall, it feeds fine...except for the 300 gr HP.

CMMG 10 round mag which is a modified Lancer mag with metal feed lips made for the SOCOM will feed everything, crimped or uncrimped, including the 300 gr HP.

AR-Stoner (Midway's brand) 5 round mag wouldn't feed anything until I did extensive modification on it. Now it feeds everything except the 300 gr HP.