300blk or 458socom?

[Oreo]

So I'm thinking I want to build an AR15 upper in a cast boolit friendly cartridge. Or, at least, more friendly then 223. I don't want to have to work that hard to get good results. My research leads me to these two calibers as potential good options. I'd like to know more about how these two cartridges compare and contrast.

Thanks in advance!

[GRUMPA]

From my point of view I would go in the direction of what's easier to obtain. Since I make the 300BLK cases the parent case (5.56/223) is very easy to obtain, for that matter so are the boolits, moulds etc. The 458 Socom I have no clue about to be honest.

Just my .02

[rockrat]

300 blk hands down

[Lefty Red]

Yep, 2nd the 300blk!

My next AR will be in that caliber. And I still don't know why the PD doesn't go to it. Better bullet and lower speeds in an urban environment. My $0.02 and well worth the cost!

Jerry

[thehouseproduct]

I'll admit that the 300blk is simpler because it uses stock mags, bolt, etc. I think the 458 might be more entertaining to try a wider variety of molds and boolits than 300blk. 458 is my next upper. On the other hand I already have the blk.

[Tdart]

The flip side, from my perspective is that "everyone" has a 300. Now, that's my way of thinking, but it's true.
The socom will take any 458 rifle mold, of which there are many. It uses standard 223 magazines, which I think the 300 should as well. With it, you get the option to shoot up to 600 grain bullets and down to 180's. That's just plain fun. Brass is obtainable, but not makeable if I am remembering correctly. I do not have a 458, but it is on my short list.

[Oreo]

I think I want to look at this in terms of performance only. I'm aware of the equipment / brass issues.

[kencha]

Both!

I picked the 458 Socom first simply because of NE hunting regulations:

.22-caliber or larger rifle that deliver at least 900
foot-pounds of energy at 100 yards

You're not going to do that with a 300blk subsonically. 500+ grain 458 can get you there.

[Artful]

So I'm thinking I want to build an AR15 upper in a cast boolit friendly cartridge.
Or, at least, more friendly then 223. I don't want to have to work that hard to get good results.
My research leads me to these two calibers as potential good options.
I'd like to know more about how these two cartridges compare and contrast.

Thanks in advance!

Remington 300 AAC Blackout - Factory
300 Black L300AAC2____Closed-Tip Flat Base____ 115 2285fps 1332 ft/lb
300 Black PRA300AAC5__AccuTip Boat Tail______ 125 2215fps 1360 ft/lb -zero at 150yds 4_ inches low at 200 w/814 ft/lbs @ 1713fps
300 Black RM300AAC6___MatchKing Flat Base____125 2215fps 1360 ft/lb
300 Black R300AAC8____MatchKing BTHP_______ 220 1015fps 503 ft/lb - zero at 100yds 34+ inches low at 200 w/ 448 ft/lbs @ 958fps
300 Black PHH300AAC1__Barnes TSX___________130 2075fps 1406 ft/lb

450 Bushmaster - factory
http://www.450bushmaster.net/viewforum.php?f=1&sid=11b7ce8cb8136c3a59591947c88345c9
One of the strongest arguments for the .450 Bushmaster is the ability to use many of the bullets available for other handcannons like the .460 S&W Magnum and .454Casull.
The .450 Bushmaster looks very much like a rimless .460 S&W Magnum and the case holds about the same amount of powder. And you can buy reasonably priced off the shelf ammo.

http://www.youtube.com/watch?v=sC0f5wvgGew
Hornaday 250 gr (16 g) SST 2,214 ft/s (675 m/s) 2,722 ft·lbf (3,691 J)
Trajectory (inches)
MUZZLE 100 200 300
-2.00 2.50 -3.40 -24.50


458 SOCOM - http://www.teppojutsu.com/458.htm
http://www.teppojutsu.com/458FAQ.htm
http://i2.photobucket.com/albums/y40/blue-nuts/458SR1.jpg


300 grain remington hp velocity 1981 average , 100 yd zero 200 yds 11 inch drop 300 yds 41 inch drop
with a 100 yard zero a 405 grain Remington soft point at 1,600 FPS will need about 7 1/2 MOA correction (15 3/4") at 200 yards.

So as you want to cast for this rifle ...
Largest mold selection has to be 30 caliber. Several companies Lee, NOE, Accurate, etc have heavies for 300 blk already done.
.458 has pretty good selection of molds as well. .452 not as many choices in but up to 400 grains available. And you could take .458's and squeeze them (once in .454 then in .452) but I don't know about accuracy then.

[Oreo]

One thing that bugs me about the 450 bushmaster is that I think barrels and bolts are only available from Bushmaster because its proprietary. Otherwise, I agree that it looks good, on paper at least.

[xacex]

1. 300 Blackout
2. 50 Beowulf

If you are going to a thumper why mess around. The 300BO has been a blast with cast. I am thinking about building another one in carbine length with pistol gas just so I can play with different powders. That would be my third one.:grin:

[GabbyM]

What do you mean by performance? Paper , Hogs or charging Chisel Tooth's.

Have you a 223 barrel made with a 223 SAMI Chamber not a NATO and get a 12 or 14 twist rate. BE a bit light on the thud factor for hog hunting. Little bullets slow down fast from there low B.C. Start out at 2200 fps and you're still holding super sonic at 200 but you're about done there. I just bought a new bolt gun in 222 Rem just for shooting cast boolits. Of course if that's not big enough I have a 30-30 then a 30-06 dedicated to cast.

One of our members here has a 25-223 in an AR. Now that's sweet. I like a 6 x 45mm too. All you have to do forming brass for the 6x45 or 25 x 223 is to expand the neck. In the end it's just how big a bullet you want to shoot.

[Littleton Shot Maker]

talked with some one recently that had to go through Starline and order 1000 peices of brass just so he would have 100-200 for himself and is selling the rest off.
I cast some lead bullets that went to testing some socom ammo, and he loved the 300gr 45-70 bullets we did.

The blkout will be easier to obtain components for at this time for sure. I like the idea of the 30 cal bullets too, can now load blkout and 308 with one bullet type.
socom and the blkout both have a function, depends on your mission parameters, and the intent you want to inflict on the target.
Lots of socom guns out there, very little in the way of loaders commercial- or brass.
Also reported to us was the fact the socom brass was not getting more than 3-5 shots per piece, I question that But I am no loading expert, nor metallurgist.

YES they where shooting lead in the D.I. gas port system, no leading and no failures, But I would be checking allot to make for my own piece of mind.

[popper]

Looking for a BO now, thinking of a Diamondback. Basically a SA 30/30.

[GabbyM]

Looking for a BO now, thinking of a Diamondback. Basically a SA 30/30.

Oh sacrilege. Popper you’ve hit one of my pet peeves. Realize you know better but others may actually believe that. You need the purple text on there.

Anybody, show me where a 300 BO shoots 170 grain bullets at 2,340 fps. Charts I see show the BO falling just short of 2,000 fps with a 155 grain J bullet. 30-30 is still pushing a #311041 that fast at 100 yards.

I’m not impressed at all with 300 BO ballistics. They make a good package for suppressed systems. But without a can they have little reason to exist. Here in the State of Illinois I can't own a can so that may have some influence on my lack of excitement.

[winchester85]

i have a 300bo, but do not shoot cast. it is my second upper in the caliber, the first was a used one from gunbroker. the first upper i could NOT get accuracy worth anything. so i had one custom made by a reputable high quality manufacturer. it is set up with 1-8 twist, pistol length gas system, and 16" barrel. with supersonic bullets accuracy has been fair. i do not easily achieve sub-moa accuracy. with subsonic rounds it is even tougher to get accuracy.
another guy on here sent me the specifics for his load that is said to be sub-moa. unfortunately i can't find the powder he uses. but i went back to my own loads and through very specific charge weights, and specific seating depth, i have achieved moa accuracy.

however a friend was at the shot show and did some asking around (he has a custom built upper as well), in talking with a few guys there, there is a belief that the round is NOT as inherently accurate as other rounds. one guy he talked to worked for Colt's military sales department. he mentioned that the round is NOT desired by the military. and suggested that poor accuracy was common.

now that i have a subsonic round that shoots well enough for fox and coyotes, i like the round a lot more. BUT, the subsonic 220gr bullet drops so fast that for each 10 yards either way of my zero range, the drop is about 1.5". so zeroed at 100 yards, shooting at a coyote at 130, i need to aim high! or if the coyote is at 60 yards, i need to aim low!
the super sonic rounds are very impressive for their size, but are still a light load compared to any other round. i shoot a 125gr tnt and it does very well on coyotes, but is only traveling at 2200 fps.

the 300BO is a shorter range round regardless of the type of bullet it it loaded with.

[koehlerrk]

The biggest problem people have with the 300 Blackout, 300 Whisper, 30/221, or whatever other name you want to hang on it is that they don't understand the round.

It was designed to work best from a 10-12 inch barrel with a 1-8 twist. Can it be used in other setups... sure, but it won't do as well. It is a short-range low-recoil high-impact round that uses mostly standard AR-15 and M-16 parts. The only real change is the barrel...

When used as designed, it's a good round. When pushed outside it's capabilities... accuracy suffers. Sounds like just about any other round.

That said, I'm building one on a bolt action rifle for my daughter to use as a 200 yard deer rifle. Small, light, low recoil, sounds perfect for a young shooter. JMHO, YMMV.

[popper]

GabbyM - a 168 gr @ 2000 is still 1800 @ 100. Good enough for hunting, a bit faster than I load my 30/30. I'd really like a 1:9 or 1:10 over the normal 1:8 16". I need to investigate the pistol gas with adjustable block - for lighter loads (2400?). Yes it is a short range round, if I need longer I can load my 30/30 with LeverE/FTX or use the 308. So, S-A 30/30 light? I think my GKs would have a ball shooting it.

[xacex]

I have noticed that the Blackout/Fireball/whisper cartridge is inherently sensitive to loading practice. Charge weight,annealing,neck tension, crimp and bullet design seem to be more critical to accuracy. While I can load up jacketed .223, or 6.5 Grendel and have nice tiny groups at 100 yards without much fuss, the Blackout is a different story. Out of the 3 years I have been playing with it I have only got one load that will do under 1" at 50 yards for 5 rounds, and that is a cast load. Subsonic it seems to shoot great,but supers are the challenge.
Just ordered another barrel for my third one. Carbine with pistol gas. I have to put an adjustable gas block on it, but it should let me play with a larger variety of powders.

[popper]

xaces - which bbl? Twist? Why does the bbl have the short thin section on it? My SIL is trying to get me to build a complete rifle, don't know if I want to play with trying to get HS right.

[Tackleberry41]

300 is pretty easy, since 223 brass isnt hard to get. Last gun show a vender had a big barrel of ready to load 300AAc brass. While the 458, brass is not cheap, midway gets $83/100, if they had any. And it cant be made from anything else.

When it comes to knock down well the 458 will do it. Subsonic weight is where its at, 220gr is about as heavy as you can get in the 300. 405gr is really common in 458 calibers.

I went with 45-70 since I already had one, not much different than 458 except the rim. 500gr at 1000fps still has almost 1000ftlbs at 300yds. Only issue with 45-70 is barrels, fast twist is not really an option in a factory gun. A long 500gr spitzer is barely stable out of the H&R I have, losses it further out. I bought a 1-14 twist blank from green mountain and put it in a spare barrel I had.

[RichardSATX]

300 BO. I'm converting one of mine right now. I chose it for a number of reasons. Brass, mag capacity, bullets, it just made sense to me. Plus, just needed to change a barrel, although I'm rebuilding the whole gun while I'm at it.

[wlc]

While the 458 would definitely be a fun stomper in an AR, I'd have to pick the 300blk. The 458 stuff (barrels, brass etc) is almost unobtainium and more expensive. To me the lure of the blk was the ease of getting into it.

[winchester85]

i have had the most difficulty with accuracy with 220gr subsonic loads, which is what the cartridge was originally developed for. my first upper which was supposed to have a shilen select match barrel, 1-8 twist, pistol length gas system, would not group within an 8-1/2x11 piece of paper at 100 yards. i tried numerous different loads with different brass, different primers, different powders, and different seating depths. with the new upper that i had custom built, i can get 1.25" with supersonic ammo with no effort at all, getting under an inch has been a little more elusive. with subsonics, i can get under an inch at 50 yards without much effort, but to get under an inch at 100 yards has taken quite a bit more effort. i did a lot of internet research trying to find actual first hand accounts of sub moa accuracy at 100 yards. i found almost none, most was in the 2 to 3 minute range!

for an ar-15 to cycle with subsonic rounds i am pretty certain that it needs a pistol length gas system.

if you want one, get one. just realize that it has many limitations, not the least of which is accuracy.

[GabbyM]

http://castboolits.gunloads.com/showthread.php?170384-AR15-25-223cal

Here is the old thread by Blammer showing off his then new 25 - 223.
May not be for everyone. That's why we have about a thousand different chambering's around.
But it's good for a look before deciding on a special caliber AR-15 build.

I've never owned such a beast nor a 300 BO. However always liked this one. Plus the 6x45mm.
If you shoot J bullets. Plenty around for the old 14 twist 250-3000 Savage that would be the right length and designed for big game.
25 caliber would be the obvious choice for anything larger than varmints like coyote. But the 80 grain flat base jacketed bullets in a 6mm are formidable. At nearly 3,000 fps. I shoot cast in my 243's and would consider that for small game and varmints. Here in Illinois that's all we are allowed to shoot with rifles anyway. Fact that I already own piles of 6mm stuff would play into my choice. 1:12" twist barrel 6x45mm. Just run 223 cases in a FL die and load.

[xacex]

xaces - which bbl? Twist? Why does the bbl have the short thin section on it? My SIL is trying to get me to build a complete rifle, don't know if I want to play with trying to get HS right.

I wouldn't worry about HS with the AR's just use a go-no go gauge and you will be ok.The barrels come with the extension already headspaced. I have built over a dozen now, and several extra uppers for family. You should have no problem building one.The barrel I ordered is a CMMG with a 1-7. It will over stabilize, but that is ok it won't be a subsonic hunting carbine. Also, the threads on the muzzle may not be concentric to the bore according to some, but I have a 8.5" CMMG and it was just fine.Not an issue unless you are putting a silencer on it, but I will know if it is OK before I put a suppressor on the end. It was a special because they discontinued the pistol gassed carbine barrels, 155$ on Midway. OK by me because I already have 2, 1-8 twist 300 BO, and want to see if 1-7 makes a difference in accuracy.Only issue is it uses a bull barrel gas block, and only one company I know of makes an adjustable gas block for it. As for short thin sections on some M4 style barrels I understand that it is for a grenade launcher and not needed (or desired) for civilians as it is a weak spot on the barrel. But, some like the military tactacool look of the M4 barrel so they put the notch in.

[427smith]

Can't believe a member of CAST BOOLITS can't think of a reason for 300 BO. cast in a semi auto that functions perfect, whats not to like.

[xacex]

Can't believe a member of CAST BOOLITS can't think of a reason for 300 BO. cast in a semi auto that functions perfect, whats not to like.

And it maxes out at cast boolit speed with pistol powder!

[bnelson06]

Love casting for and shooting my BO the end.

[wlc]

i have had the most difficulty with accuracy with 220gr subsonic loads, which is what the cartridge was originally developed for. my first upper which was supposed to have a shilen select match barrel, 1-8 twist, pistol length gas system, would not group within an 8-1/2x11 piece of paper at 100 yards. i tried numerous different loads with different brass, different primers, different powders, and different seating depths. with the new upper that i had custom built, i can get 1.25" with supersonic ammo with no effort at all, getting under an inch has been a little more elusive. with subsonics, i can get under an inch at 50 yards without much effort, but to get under an inch at 100 yards has taken quite a bit more effort. i did a lot of internet research trying to find actual first hand accounts of sub moa accuracy at 100 yards. i found almost none, most was in the 2 to 3 minute range!

for an ar-15 to cycle with subsonic rounds i am pretty certain that it needs a pistol length gas system. if you want one, get one. just realize that it has many limitations, not the least of which is accuracy.


I agree with you on the accuracy. Mine is not a tack driver. It is decent with subs (1.25" or less at 50). I am working on a load now that shows promise, but My range is maxed at 50 so I'll not soon find out what it'll do at 100. I loaded some supers this afternoon that almost made one ragged hole at 50.

Back to what I highlighted. It will certainly cycle subs with a carbine length gas system. That's what I have and it does fine. I will say though, that a pistol gassed gun, even with a 16 inch barrel will give you more options in powder choice than a carbine gassed gun. If you go that route you MAY need/want an adjustable gas block though. I've had the best luck with consistent cycling so far with 1680 and RL7 with my subs.

[lmfd20]

I have both. My BO is great with the suppressor and subs. My 458 is never disappointing.

[gpidaho]

I was looking through a box of left overs from guns Ive sold when I came across a round of 458 Socom Id save from my Rock River AR (Long ago sold) Pretty spendy shooting for a poor boy. Got me thinking, anybody ever build a custom single shot in 458 Socom to fly lead? GP

[ourflat]

Have a DD300 BO now and will seek the inner wulf in me for my next gun!

Frank

[dkf]

I was looking through a box of left overs from guns Ive sold when I came across a round of 458 Socom Id save from my Rock River AR (Long ago sold) Pretty spendy shooting for a poor boy. Got me thinking, anybody ever build a custom single shot in 458 Socom to fly lead? GP

Yeah I saw single shot pistols and rifles in .458 over at the .458socom forum.

My next build will be a .458. Have no use for a .300blk.

[GARD72977]

Im slowly building a 300 but I really want a SBR 458.

[mtnman31]

I own both. I have had a Tromix .458 SOCOM upper since around 2003. I have a 300 BO AR upper (bought from board member Subsonic) that is still fairly new and an Encore barrel as well. I don't have nearly as much experience with the 300 as the 458. Yes, brass is more expensive for the 458. I also paid a premium for my SOCOM upper because I bought it when it was fresh to the market and there was little competition amongst manufacturers. The 300 AR upper is really nice and well made. Of course, 300 brass is cheap and readily available any day of the week. From a purely monetary aspect, the 300 is a better deal.

In my opinion and for my needs, the 458 would be the route to go. My rifles are for hunting or self-defense. If I was in a self defense situation, I'd clearly want the power of the SOCOM. If I am hunting, the SOCOM might not be appropriate, but by the same token, I wouldn't use the 300 either. I'd just use my trusty .308 bolt gun.
So, there you go, get a .458 SOCOM or step up to the AR10 platform and get a .308. I'm shopping for an LMT in .308, myself.
Your only other option is to get both a 458 and a 300 BO and decide for yourself.

BTW - for fun and enjoyment, the 458 is a winner. It is always a favorite when I let my friends shoot it.

[dkf]

Is the Tromax good quality, any issues?

I am looking at picking up one of their 16.25" .458 barrels and bolts.

[xacex]

I was pondering one of thier 10.5" 458 barrels, but since I am already invested with the wulf I think I will stay with it for the shorty as well. I like the pistols for hunting, and since they are legal I would like a 10.5" wulf for black timber elk. I can't imagine what the recoil will be like. Tank break?

[Smoke4320]

I have both the 300 Blkout 10.5 SBR and a RRA 458 socom .. Each does something well ..
the Blackout is just a fun gun to shoot .. subs are a hoot and the milhec 359 159 HPs are a 150 yd deer killer

the 458 is a big bore deer/hog killer specialist or a great subsonic sledgehammer.. Mine loves the RCBS 45 325 FN and the Lee 459 500 3R.. can be loaded mild to wild
if you don't have a 458 call tromix and get a barrel and bolt you will not regret it

[mtnman31]

The Tromix is great. I have no issues with it. It is older and I'm pretty sure at that time he was modifying other manufacturer's parts to make his uppers. At some point I'll probably upgrade the handguard to something a little more current and lighter. I got it second hand in like-new condition. I don't think the previous owner had put more than a box of ammo through it. Never any issues with it and the ported barrel is beautiful.


Is the Tromax good quality, any issues?

I am looking at picking up one of their 16.25" .458 barrels and bolts.

[dkf]

The new Tromix barrels seem to be well liked by the people whom have bought them so far. I'll pick one up and put it on the shelf until I get to building the rifle.

[Sig556r]

Lotsa BO haters here...I cast/load for both my 300BLK & 458SC & love the way they're designed to shoot.
The 300 BLK is really quiet with 200-grainers & up in AR suppressed, all you can hear is the action of the bolt. It's optimized for pistol gas tube (not necessarily pistol length barrels) for cycling subs although anything beyond 12"-14" wont increase efficiency. It's likewise lethal in supers (110g TAC-TX, TSX or A-Max/V-Max) at around 2350fps for medium game. I also got a RAP bolt action that runs supers & subs flawlessly, even those that wont cycle my ARs.
My 450 Socom started as a rough Radical barrel/bolt combo, but with a little elbow grease, was able to run smooth. I run Berry's plated & 300g to 500g cast. Its supposed to run with standard AR buffer/spring but you need to tweak it to cycle depending on your load. Brass is expensive & casting can drain your pot much quicker than your regular 150g boolits. You need to modify GI mags to work or use lancer mags out of the box. Magpuls don't seem to be a good match.
Either one will put a smile in your face, paper targets & game.
Good shooting!

[Stuckcase]

I have had nothing good come out of lead in the BO. Jacketed has been exactly as expected. Lead has had issues with bullet design feeding in mags, loading depth issues, and set back in chambers even when crimped. Could just be my gun with three different barrels/feed ramps---but I don't think so. I have abandoned all lead attempts in my BO. I have also abandoned the need for ultra quiet with it. I have found the most satisfaction out of the BO as follows:
My load, my gun---use at your own risk
Federal trimmed brass
CCI 450 mag primer
AA 1680 19 grains
Speer 180 gr BTSP
Out of my 8" barrel suppressed---0 reliabillity issues. Excellent accuracy---expansion on deer under 125 yards---DRT twice with shots behind the front shoulder on deer

[Stuckcase]

458 SOCOM is a bruiser. Adequate for short range work---excellent for the smile affect after touching it off. Every AR lover should have one. If to choose however, BO wins every time because of its flexibillity and simplicity. Easiest cartridge to load. Brass is cheap as dirt. Its a 30 cal. Imitate mike drop at this time!