Anyone know why they quit making it?

nope. but i would like a bolt and barrel for one.
or
maybe in 300wsm !

I think not a lot of market interest. You can still find the barrels out there...

Does Armalite still make a .300 RSAUM AR10?

The 300 RSAUM isn't listed in Armalites catalog. 260 and 243 are though.

I talked to a sales rep once who stated it was a perfect fit for the AR-10 pressure wise. Guess that's why he is in sales...

Any time a company drops a product it is because of lack of sales

I have that caliber on my list too... but I'd have not bought a factory one anyway....

It was a nice upper, only made in the LR heavy barrel model with only a 5 shot magazine available. Accuracy could be 3 in 1" with match grade ammo. You ended up with a 12 pound (scoped and loaded) rifle. Really would not do anything a Browning BAR in 300 WSM or a Benelli in 300 WinMag would not and you don't need set of wheels to move either of them.

Yeah, but neither the BAR or the Benelli was an AR... Once I have lowers, why not the good uppers... grins...

I don't think it would hold up to the strain, sort of like a 10mm 1911. It took them a LONG time to get an AR10 that would hold up.

Why not? its all the same pressure you are dealing with. Bolt carrier mass absorbs the pounding, you manipulate the gas port sizes depending....

Beyond that there is no reason any cartridge made that would fit the platform size, wouldn't be made to safely and easily work.

5.56 isn't exactly low pressure rounds.. and all the 600 yard plus reloads I've fired in my ARs have been not mild loads at all. Work it around the round when you build it and life is typically fine.

Disclaimer, I have, lets just say, more than most when it comes to AR lowers... but I only have one AR10 lower so far and its still not assembled.... so I could be wrong.

Never heard of a DPMS 300 SAUM failing. (or any DPMS for that matter)
As for the BAR and R1 either one may be bought for the same price as a mint 300 SAUM upper. The R1 also may change calibers by swapping bolt faces, barrels and magazines (at worst). 300 WSM to 270 WSM is just a barrel swap.

Point missed, was that regardless of what you can swap on the R1 its not an AR. Thats the appeal to me since I've shot the AR platform since 89 in competion, its second nature to me. Why not own a bunch of non competition calibers in it.

For others nothing wrong with the R1 or the BAR. I"ve had the BAR. They are an ok gun. Never as accurate as a good AR though.

The AR-10 I had was a 16" mid length gas system 308. It would run fine pushing a 150 grain bullet up to 2700 fps, after that it would pull rims. Overgassed, undersprung and too light of a buffer at 5.4oz.

A fellow that went by slash on arfcom used to sell heavy buffers for the AR-10's that weighed 9.6 oz. or so just to combat the problem. They weren't cheap either.

The problem wasn't as bad in a rifle length gas but it was there. The sales rep from Armalite allowed the 300saum worked much better and seemed to just fit, especially in the magnum craze. I thought they'd get behind that round but I guess it never had a chance.

I have no further use for an AR-10 of any brand.

I have no further use for an AR-10 of any brand.

Thats the same many folks said about the M16 when it first came out.....

And then again when idiots built them with light carriers and same normal size gas ports and were shooting 80s and ripping rims off....

nope. but i would like a bolt and barrel for one.

They can be made to work but let me rephrase it, I've no further use for a 10 pound carbean.

Hows that?

I shoot 175s out of a 20" AR10 using 45.5gr of Varget. It is just peachy with that load.

It actually started out as a carbine. I thought that it was heavy for a carbine. Then I stuck the 20" barrel on it and I feels much better. I don't think it is any heavier, and it balances better.

I can hear ya there, never figured the AR10 for a light combat type platform anyway, and alwyas figured that I can do what I need done with a light AR15 given the ability to choose my ammo....
The AR10s are just hunting guns, and fun guns.. just for the hell of it.... Heck a good upper costs more than a decent bolt gun....

Yeah and the folks who said it about the M 16 were correct due to the idiots in DOD putting ball powder in it and telling the troops it never needed to be cleaned.
We've all read about the dead troops in Nam' beside their opened up M16s that had jammed. The AK 47 was superior then and for normal combat it still is today.

As for the AR/BAR/R1, I was talking about hunting, not target rifles. Still waiting for any AR to take home a Target trophy in National F Class.

A 308 tactical AR 10 16" has a use (killing people at 300 meters or less), all the rest are just too heavy or underpowered or short ranged to be an all around rifle.
Folks who have a choice don't bring a 223 to a fight if they can get their hands on a M14 in 308.

"Folks who have a choice don't bring a 223 to a fight if they can get their hands on a M14 in 308."

Interesting, there's a thread on m4carbine right now on what is the best for a DMR. The M14 is issued but there were a few who said they left it and grabbed their M4 if urban fighting was expected. The M14 especially with the special stock was too heavy. I've never been in a fire fight and can't say one way or the other but the discussion brings up good points from folks who have.

http://www.m4carbine.net/showthread.php?t=70417

Light weight and .308 battle rifle/carbine/whatever don't go together.

I know a guy with an AR in F class.... but he isn't to that level and won't be due to life...
Of course if I was still shooting and had interest in F class I could show you the first trophy in F class to an AR.

That being said if its killing folks to 300M only, I damn sure would not grab my M1A/M14s in the safe... good short AR and life would be swell.
If it has to do with penetrating barrier issues at 300M is going to be the key, then I have a tool for that. But it is also NOT my M14s....

As I've said before, if I need something other than 223, it won't be an AR of any sort. AR's serve a purpose, extend beyond that purpose and grab something like this

and rock on.

To each his own. That being said I have em that look a lot like that bolt gun too.

Its just damn fun to grab ARs of various calibers.

Of course I have the specialty guns too, but I love playing with, hunting, shooting etc... the AR. Just a love of mine. Kind of a disease.

But then the 7x300 wtby is not an AR, the 308 bolt gun ain't either, the lightweight 284 win ain't either.... so I do have various tools.

But I won't be shy about having a 6.5x284 upper for the 10 either....

And really if you get right down to it, you could do ANYTHING you need to with either all AR platforms, or all bolt gun platforms. Doesn't mean one is right and one is wrong.