[Difranco]

Eric I think you missed this thread here
http://xcrforum.com/index.php/topic,11983.msg165232.html#msg165232

and his blog write-up
http://emptormaven.com/2011/09/7-62-thumper-subsonic-xcr-rifle/

This is the route I will probably go...

 

[Difranco]

I have one question about his subsonic load, Why is it still loud? Check out my subsonic ammo I loaded up with .308 bullets using my Savage and YHM Phantom Silencer.

http://youtu.be/GkFhBR8tXT0

Hard to say from the two recordings. Could be sensitivity of the mics on the cameras maybe? Different Silencers will sound different.

I also wonder if environmental factors play a role such as humidity, barometric pressure, etc.? These do affect the calculation for the speed of sound, so it does seem to reason that sound waves maybe affected in general?

I do think having a 7.62x39 barrel for .308 handloads is just an awesome idea as it opens up the field to a wide range of bullets.

 

[Difranco]

Is it true that the 7.62x51 Nato cartridge has a 7.82mm bullet diameter?! Then why do they call it 7.62x51?

All this time I thought 7.62x51 Nato was the same as 308 except for pressure. Therefore I assume 7.62x51 and 7.62x39 had the same diameter bullets. What am I missing about nomenclature?

the short of it...

7.62 millimeters equals .3 inches.

7.62 mm is just another way to say "thirty cal"

You aren't missing anything about nomenclature other than it's inaccurate in a sense. You really shouldn't have to worry about bullet diameter unless you are reloading.