Guys,
I have  an extra 300 whisper upper, but really want to get more out of this particular upper.  It appears that it would be feasable to take the barrel off and ream the chamber to fit the blackout?

If so, anybody have a source for a 300 blackout reamer?

Thanks
Hank

go to the silencertalk.com forum - they have a 300blk forum there with a ton of info. The 300blk looks like the way of the future!

You will not gain any significant increase in velocity because the 300 Blockout is pretty much the same case as the 300-221 Fireball/300 Whisper.  There is ony a difference of a few thousands here and there.  Depending on the reamer that was used to cut your chamber, you  should be able to shoot 300 blackout ammo in your upper. You will have to check  your chamber to see exactly how similar it is with the SAMII standard.

320pf

You can't just ream out an existing chamber.  Doing so would alter the headspace which is something you can't fix as that would cause problems with the gas tube length.



All of which is moot cause the 300 Blk is the same thing as a 300 Whisper.  The Blk is just a saami standardized 300 whisper.