You ever have a brain fart?

Seems after having two brain surgeries... The first one in January of 2008 and the second one in April of 2012... I've been having LOTS and LOTS of brain farts... Oh well, just my luck! LOL

The 300 Blackout was specifically designed to be an updated version of the 300 Whisper - the Whisper series being subsonic rounds designed for suppressor use - these are CQC (close quarters combat) cartridges. Because the 300 Blackout was designed to toss the biggest chunk of lead possible at 990fps - this is a horrible cartridge to get into with long distance hunting in mind. Because everybody will be working with the different powders and projectiles for subsonic use - you would be an orphan as one of the few guys trying to beef up the speed. That - and the upper you buy will be made with subsonic velocites and pressures in mind - good chance you could accidentally damage the upper receiver trying to get long distance performace form this in an AR. In a bolt gun - this would not be an issue.

When you read into the forums of the 300 Blackout - you will see that folks are discussing using cast bullets, gas check style bullets, lead alloys etc - they are going in the opposite direction you need to be for hunting. This means you woud be on your own and breaking new ground - it has been experience that breaking new ground in handloading almost always means breaking new guns too.

My co-worker has both the 6.5 and 6.8. He speaks well of both. If you email me - I will ask him which one is his favorite and why. He's been all over these two cartridges for a decade - both in AR's and Contenders.

The only reason for a 24" barrel is to increase the sight radius when using iron sights. If you gonna build up a flattop and never use or install install iron sights - the smaller 20" barrel or 18" will be lots more practical for hunting. People who are stuck with factory ammo might have no choice but to go with a 24" to get better performance, but, since you reload you can easily find a powder, projectile and load that will make up for the lost 50-70 fps from the missing 4".

I have a 6.8 that I built and I love it, my favorite gun. I helped a friend out when he had a hog problem. The 6.8 did great at quick, clean kills. I don't have any other experience with the other two calibers except that I've shot a 6.5. It was pretty similar to the 6.8 IMO. Didn't shoot groups with it so I don't know how accurate the round is. It's ballistically similar (or superior) to the 6.8 but when I was deciding between the two, I chose 6.8 because of ammo availability. 6.5 is alot less common.

My son has plans of building a 6.5 Grendel/.264 LBC upper for his AR. We have not researched the .300, but it appears that the 6.5 Grendel is superior to the 6.8 SPC. He would use it mostly for deer hunting out to 300 yds. He has the brass and dies. You can make 6.5 brass from 7.62x39 brass. It does appear that Bill Alexander is trying to kill off the 6.5, but LBC may take up the slack with their .264.

sure. in many situations. Tom Eichele, a neuroscientist on the college of Bergen in Norway, replaced into element of a worldwide group of researchers who pointed out data that the suggestions fart is detectable in suggestions scans as much as 30 seconds before the errors is nicely made... The scientific term they gave the phenomenon is "maladaptive suggestions interest exchange."

Hell, that's nothing.I had one and wound at ended up getting married.Sorry but I can't answer the rest of your question