Decided to re-barrel my Savage Model 12 from .223 to .270 WSM.  I'll have to change the bolt face too.  I got to thinking, I can do this because the .270 WSM works in short actions not unlike the venerable .223 and 308.  So why not build a .270 WSM upper for my AR-10 too!  Has it been done? If so, what's the up and down sides to doing it?

The ballistics to the .270 WSM are great.

Here is my AR-BMG Innovations .300 WSM upper with a POF lower. The bolt face has to be machined to the larger diameter of the WSM cartridge and the extractor and ejection port need to be modified. Mine runs just as well as my DPMS .308 if not better.

After I posted this thread, I came across a Shooting Times article that stated the military and Armalite would not use the WSM case because it's web was to week and bulges occurred just ahead of the rim.  Instead, the went with the .300 RSAUM, because it had a stronger web and overall a stronger cartridge.  The military has used this custom Armalite on a limited basis.  Seems that I'll have to do more research.

You might want to be researching the difference in the 223 Savage action and the WSM, namely barrel tenon diameter and the standing ejector.


They increased the barrel tenon diameter for a reason on the WSM, RUM and Precision/Target actions.