.450 Bushmaster vs. .458 SOCOM (Elk/Black Bear hunting and target shooting)


September 2, 2010, 11:00 PM
Ive been doing quite a bit of research about AR thumpers and have narrowed it down to these 2. The upper will be used for medium/large game hunting in Idaho(Mule deer, Elk and maybe black bear) and was curious about your guys' opinion. Also, I dont need to stop any vehicles by shooting into the block so that argument is moot IMO.

Basically almost everything I would order would be from midway just to keep pricing/ordering consistant. I will be reloading either one to help negate costs but will still order factory ammo to get things rolling and replicate loads. Im looking at both options in their cost to shoot/reload and its big game effectiveness.

Brass cost: Almost a toss up. The .458 SOCOM brass is a tad cheaper than the .450 Bushamster. Its ~$.79/piece for .458 SOCOM and $.84/piece for .450 Bushmaster. Although the .458 SOCOM is a tad cheaper, its made by Starline and .450 is made by Hornady. Starline isnt junk by any means, I just think Hornady brass is better quality.

Bullet cost: Again, a toss up. .452" ammunition is cheaper but the .458" bullets are a bit larger and offer a tad better selection in +250gr. weights.

Upper cost: Basically equal depending on any deals going.

Factory ammo cost: Here a significant edge is given to the .450 Bushamster. Although the .458 SOCOM has a better selection, its much more expensive. The cheapest load made by SBR is $47/20 rounds where as Hornadys ammo is $28/20 rounds. That is a significant difference.

Hunting effectiveness: This is where I may need some guidance. I know the argument is that the .458 SOCOM uses a better suited bullet for hunting over the .450 Bushmaster, yet I know there's plenty of Elk, Moose, Caribou and Bears that are dropped with a .454 Casull. Is there really that much difference? I can see a heavy .458 cal bullet holding up better in the shoulder of an Elk, but I dont believe there will be a difference when either shot is placed in the vitals.

The .450 Bushmaster ballistics seem to look better on paper. Im not aware of any light(250gr.) .458 SOCOM loads but the .450 Bushmaster seems to have better energy and to be the flatter shooting cartridge. I havent found many sub 250gr .458" bullets. So in .450 Bushmaster, a 200gr. bullet flying at 2,500fps doesnt sound too bad.

Am I missing anything here? Im leaning towads the .450 but just wanted to hear your input. Thanks.

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September 2, 2010, 11:18 PM
I would go with the 458 socom. I did, I have a Rock River 458.

When I was looking into the two I found that there were a few things that helped make the decision.

1. The bottle necked case of the 458 makes extraction easier. I had read that the straight case of the 450 can have a little harder of a time with extractions.

2. Bullet selection for the 450 was pretty much for pistol cartridges where the 458 can be loaded with 45-70 bullets and if you need better penetration 458 winchester bullets can be utilized.

The 458 just seemed to be the better choice overall. YMMV.

September 2, 2010, 11:50 PM
I voted for the Bushmaster; anything with SOCOM in the name is too Mall Ninja for my taste. Also, with Remington and Hornady selling ammo I think it's more likely to be around for a while.

September 2, 2010, 11:50 PM
I'd go with bullet selection, for what it's worth.

September 3, 2010, 12:16 AM
Is there any significant difference between a 300 grain .452" bullet and a 300 grain .458" bullet as far as its effectiveness on large game? Are the .452" bullets not rated for the velocity of the .450?

September 3, 2010, 12:59 AM
The Bushmaster should do fine with the muzzleloader bullets it was designed to fire.

I wasn't really serious about Mall Ninja comment, but now I'm wondering if Gecko45 actually could have been involved. Marty ter Weeme, the designer of the SOCOM cartridge, is the founder of this outfit:


EDIT: Reading the site, that logo is actually a Samurai. Probably no connection to Gecko45 because he was a student of the art of Ninjitsu.

September 3, 2010, 01:03 AM
The diameter difference is to small to make a real world difference.

To take an excerpt from http://www.thefirearmblog.com/blog/2010/02/18/remington-r-15-now-in-450-bushmaster/#comment-27030 since it sums it up nicely:

.452″ bullets, like the .450 Bushmaster uses, are used primarily for handguns and as muzzleloader sabots. Since these bullets are, for the most part, designed for .45 ACP, or at most .454 Casull velocities, the number of bullets that are suitably constructed for being launched in excess of 2000 fps and used against game that is tougher and thicker-skinned than deer is significantly less than you might expect for this ubiquitous caliber. Bullets designed for the .460 S&W Magnum and hot muzzleloader charges are about our only good choices, and they don’t get very heavy, capping out around 300 grains. The sectional density of such a bullet is not terribly impressive (0.21), or about the same as a 140 grain .308 caliber bullet. I wouldn’t want to use such a light for caliber bullet against elk, moose, or brown bear, for fear of inadequate penetration.

The .458 SOCOM does better in this regard, using (no surprise here) .458″ bullets, the same diameter that the venerable .45-70 uses, and at similar velocities (greatly expanding the range of usable bullets). This caliber choice offers a range of bullets from 250 to 600 grains, giving the .458 SOCOM far greater flexibility in the size of game that it can take, from small deer to bison. Its 1 in 14″ twist rate (as used by Rock River Arms) is simply better suited to the heavier bullets necessary to humanely kill large game. It is even designed to be able to launch the heavy 600 grain bullets at subsonic velocities, making for much greater effectiveness when using a suppressor.

September 3, 2010, 09:16 AM
I looked over the 450, 458 and 50 for a while and went with the 458 for bullet selection (wanting heavy bullets for suppressor use). I also like the fact that you don’t have to keep special or modified mags separate from your regular mags. If you wanted “cheap” factory ammo the 450 would win but if you don’t reload I wouldn’t suggest any of them, just go get a 45-70 lever gun.

September 3, 2010, 02:47 PM
When Midway had the sale on 450 Bushmaster uppers (which I see they still have going on), I thought about picking one up, but the more I investigated the caliber, its' performance, the bullets used, magazines, and what it took to reload, I just didn't think it was very attractive anymore. Some of those issues were ironed out with the 458 socom, but I still can't get over the fact that both of these are just equivalent to the .45-70.

September 3, 2010, 03:17 PM
but I still can't get over the fact that both of these are just equivalent to the .45-70.

I suppose it comes down to one's affinity/desire for the AR platform versus the various platforms the .45-70 is available in.

September 4, 2010, 01:30 AM
If you plan on reloading...then its the 458 SOCOM hands down.

Bullet weights from 100 gr (yes 100 gr), up to 600 gr.

I shoot mostly 300 gr and 405's from mine, but there are good 250 gr. bullets (commercially loaded too) that are good for deer and offer a slightly better trajectory.

Neither cartridge is designed to shoot "flat", it should go without saying.

And Starline brass is top-notch, you will not have any problems with it.

If you are just stuck on the 450.....then you might want to know that some of the Bushy guys are taking .458 cal bullets and swaging them down to use in the Bushmaster, this gives them more bullet choices. Seems like a lot of extra effort though...since you can just go SOCOM and load up what you want.

Velocity and trajectory are near identical for both cartridges (using like bullets).

Some FAQ's for you: http://www.ar15.com/content/page.html?id=179

Note: Some of the info is outdated, there are several sources for commercially loaded ammo and quite a good selection.

You can go the AR15 site under "variants" and read all you want about the SOCOM vs. Bushy.


September 4, 2010, 07:52 AM
If ya'll visit the hunting section here, you would know Flint is a critter killin' fellow so I'd heed his words!

September 4, 2010, 03:54 PM
Thanks for the input guys. The idea of supressing it would be pretty sweet. Maybe not now but sometime in the future, so that may be the deciding factor. I just wish SBR made the .458 ammo a bit cheaper. For the good stuff its $58/box, so at almost $3 a round, its on the same price level as alot of weatherby cartridges.

One more question: Out of the 2, which base model upper is the better deal/quality? Bushmaster or RRA?

September 4, 2010, 07:03 PM
Both uppers should be of comparable quality. You have the option... if you go with the SOCOM... to have Marty ter Weeme build you one (worth the wait).

But, for mass produced uppers you should be happy with either selection (RRA or Bushmaster).

I believe you can order a RRA already threaded to accept a Suppressor/Flash hider/Muzzle break, not sure about the Bushy.

In your first post...you stated you were not aware of any 250 rounds available for the SOCOM. SBR makes one...and midway sells it.


Here is what midway currently handles for the SOCOM:

One thing about SBR ammo though, I have found it to be pretty anemic. I understand the need to be "safe"....but they really load on the light side.

I get about 1850 fps from their 250 gr. Barnes triple shock (16" barrel).

Heck.... the Corbon 300 JHP leaves my barrel at over 1900 fps.

Your best bet is to hand-load...though I understand you want to buy commercially at first.

Anyway, I am not trying to sway you one way or the other. Either cartridge is capable of doing what you want.

Good luck with your purchase and welcome the world of "Big-Bores". :D


September 5, 2010, 02:29 PM
The only thing I didn't see discussed already is that the 450 bushmaster is based on 284 winchester brass. If Hornaday stops making brass, you can still make your own. Not that there are tons of 284 brass laying around, but still.

I bought a 450 upper when Midway had them on sale for $600 earlier this year.

The bushmaster does have a threaded muzzle. And you can still find Nosler partition bullets.

As far as Starline goes, when I had a bad batch of 30 tok, they would not warranty it.

September 5, 2010, 07:50 PM
I think that the bullet selection would be better with the Socom round, but the brass and ammo would be easier to acquire with the Bushmaster round. I may be wrong in my thinking. Since I am a handloader, I take into consideration the availability of components when purchasing a firearm. I think that a semi-auto equivalent of a .45-70 would be a handy gun to have around. I am still waiting this one out to see if it has staying power.

September 6, 2010, 03:08 PM
I never had any problems with Starline brass but I think those that have problems with new brass in general, don’t run them through their normal reloading process. I resize every case, new or old, when I load.

The RRA 458 also comes with a threaded muzzle, it’s 5/8 32tpi. Here are some photos of my 458 suppressor build.




Ike R
September 6, 2010, 03:24 PM
.458, for all of the reasons listed above. Had the chance to shoot into a "box of truth" type setup made of 35 gallon honey barrels at 25/50/100 yards with a 45/70 a 458 SOCOM and a 416 Rigby and by far the most impressive performance was with the .458. Excellent weight retention coupled with massive expansion of the projectile. Very nice.

September 6, 2010, 09:32 PM
As much as I like my 458 socom it cannot duplicate what my 45-70 can do (with the right rifle you can knock on the heals of the 458 win mag), much less other more powerful rounds. If you reload for it, as you should, it will beat factory 45-70.

September 7, 2010, 12:36 AM
Any problems on using a RRA upper on a Bushmaster lower? I know my Bushy can be picky when it comes to mags(likes Bushmaster factory and Lancer mags but it hates C product mags even though those are the only inexpensive ones i bought), so im not sure how it will handle mags with .458's in them. I was looking into the .450 so all things are matched up and planned on buying .450 specific mags so i dont have to constantly swap mag followers.

But now im leaning to the .458 but still undecided.

September 7, 2010, 12:39 AM
...but I still can't get over the fact that both of these are just equivalent to the .45-70

Its the platform. Yea the different cartridges are similar in terms of performance, but im used to the AR platform. Plus, it being semi auto will help reduce recoil and i wont have to worry about being gentle on the stock as i would with a lever gun.

September 7, 2010, 10:28 AM
Any problems on using a RRA upper on a Bushmaster lower?

I have a few different RRA uppers on DPMS lowers and LAR Manufacturing makes both Bushmaster as well as DPMS lowers so I bet you will be fine.

November 21, 2010, 07:10 PM
For the RRA .458, is there a preference in Mid or Car gas systems?

Welding Rod
November 21, 2010, 07:19 PM
The 458 is a much better match to an issue 556 magazine than the 450. While an excellent cartridge IMO, the physical dimensions of the 450 are horribly matched for the magazine in which it is intended to be used.

The 450 case is just slightly greater in diameter than the spacing between the mag feedlips. This results in a tendency for the case to push the mag lips open. In my guns, I don't think two 450 rounds coming out of a GI (or BM supplied) magazine rested in the lips at the same elevation or angle twice in a row.

Even though the external dimensions of the 450 case were very poorly "engineered" for use in a GI magazine, I must say I found the cartridge to be quite accurate and reasonably priced compared to the SOCOM.

Anyhow I have owned 2 of both. I kept the SOCOMs and was happy to be able to sell the Bushmasters for only a moderate loss.

November 28, 2010, 10:49 PM
Well Im still up in the air about it. I was leaning towards the .458 but one thing has changed, my buddy has an FFL license and through an online distributer. A .450 upper is ~$450 for him to purchase. They dont list the RRA .458 SOCOM and those run ~$700-~$750 retail for the model I want.

So that extra money could be combined with money I set aside for a scope, reloading materials, a drop in trigger or any other things.

Decisions, decisions.

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