Is this possible? (who sells these?)

If not is a regular .243 upper availible? I have seen these in Ar-10s but the Armalite site is confusing me and I can't find these in the catalog.

Looking for a .243 deer blaster (4000fps- sigh in 2.2 in high at 100yds = within 3-4inches out to 400yds!!! <this is the ticket a 4x's the speed of sound 55gr lightning bolt to pick off running deer with!

The 243 Uppers are available at this time.  As far as 243 WSSM these are not or at least I have not heard of anybody that has one available yet!

Now, why would you want to use a 55-gr varmint bullet for deer?  The bullet will explode on contact and you will have a wounded deer that will run a very long distance unless you place your shots VERY WELL!  I use the 55-gr Nosler BTs in my Rem 700 PSS in 243 and I can splatter a chuck at 400+ yards.  I would NEVER use this load on a deer!

Good Luck!

There are likely to be some engineering problems with a 243 WSSM upper.  While the round is probably short enough, it is too wide and powerful.  You'd have to make some significant alterations to the reciever, bolt and barrel.

Armalite was working on a 300 SAUM for their AR-10.

There's only one place I shoot at deer (right behind the tip of the front leg elbow ) this shot (for me anyway) has never failed to kill a deer.

{I only need the bullet to penetrate 3 inches and it will take out the heart} The 55gr should be fine for the job. As long as the Ar-10 will do under 1MOA
[b] Now all I have to do is wait for Accuracy speaks or someone else to bring out a .243WSSM conversion for the ar-10[/b]

Check out SSK, I think they have a 300WSM, if they have that they can make a 243WSM