Looking for an AR in .243. Who makes these?

I am looking at Armalite because they are the only manufacturer I know of beside DPMS which I am not interested in.

Who else makes them? Which do you suggest based on personal experience.

Any reasons not to go with the .243? I chose this because I like the versatility of the .243. Wanting something with a little more energy than the .223 but not so expensive and loud as a .308.

I found a .243 upper. Is building an AR 10 lower much different than building an AR 15?

Thanks.

Armalite also has a 10T heavy barrel upper in .260 Rem, which allows for a bit heavier bullets. I have so far found Armalite's stainless barrels to be excellent, not so sure about their steel barrels.

AR10's vary more than 15's do, as far as manufacturer dimensions. Noveske and Armalite are compatable, DPMS and Bushy differ.

The receivers on the Armalite are made of 7075T6 aluminum, while the DPMS are made of 6061. Bushmaster/Remington do not specify which alloy they use in the .308 AR models but they do specify 7075 for the AR-15 (so does DPMS, BTW.) SO this leads me to believe that Bushmaster uses 6061 in their 308 ARs, unless somebody can point me to a Bushmaster link that says otherwise.

To me, that is a BIG differentiator, which is why my planned AR-10 build starts with Armalite receivers.

Armalite and DPMS are just two to name a few for your big platform AR's. You can go the custom route and have a very nice firearm that will shoot bug holes guranteed. Look at Specialized Dynamics, Dedicated Technologies (DTech), and GAP just to get started naming a few. I just went through the same process. I am going with Specialized Dynamics. I have talked to Scott on the phone a few times and by email several times. He is building me a .260 that should be SWEET!!!!! I also have a 6.5 Grendel on the way built by him. All of these companies will build you a very fine 243. Good luck with whatever you choose

Except you cannot use the .308 Pmags with an Armalite, is that correct? Forgive my AR-10/LR308 ignorance...

Absolutely correct: From Magpul's site:

"NOTE: NOT compatible with Armalite AR-10, Noveske N6, Rock River Arms LAR8, FN SCAR 17S or any other rifles that utilize M14 type, FN FAL, or HK 91/G3 magazines."

Going for a .243 WSSM instead would let you drop back to the AR-15 platform and gain ~200 fps. 6mm BR Norma also is good for the AR-15 but will cost you ~200 fps compared to the .243 Win.

I thought the 243wssm was about the same as the 243Win, not 200fps faster.

If you want an AR10 you have to buy it from Armalite because they are the maker of the AR10. If you want an AR pattern .243, you have other options, mostly semi custom.

I just bought a used AR-10T in .243 with a 26" Rock bbl. First three shots were less than 1/2" at 100 yds. That was just for sighting in and with a run of the mil-spec trigger (I'm the third owner, previous owner took out the NM trigger, looking at several options now, leaning towards the Geissele HS match. I tend to like Armalite AR-10 platform guns over others. I don't know if it's near AR-15 mil spec aesthetics or their parkerization or what. I do jones for a p-mag that would fit instead of or in addition to the M-14 style. Are you listening Magpul??

Armalite still makes one in .243 win. Better decide right now what twist you want. Some of the long range crowd are going tighter twist to use the 107gr- 115gr pills. I've got a normal factory twist of 1/9 so I'll be limited to @100gr bullets.

Good luck.