Originally Posted By: GreyhunterOriginally Posted By: barkOriginally Posted By: GreyhunterOriginally Posted By: barkhe's running a 6.8. A little different animal than .223.
I'm not sure what you mean by that?
I would agree with you that the longer you can keep the bolt closed the quieter it will sound to the shooter. Adjustable gas block definitely helped a little, and part of the reason I want a 20" is for the rifle length gas system. LMT's enhanced bolt carriers are supposed to delay bolt unlock as well.
6.8 was designed for shorter barrels. It's easier as a reloader to find loads that have a complete burn in a 16 barrel. To my ears, the 223 is higher pitched and more painful and it's easier to find a more pleasing tone with the 6.8 or 300 blk.
When talking suppressors, most everyone uses the OSHA standard of 140 dB as hearing safe. If you don't want to use that standard personally thats fine, but there is a big difference between 140dB and 130dB. Remember the dB scale is not linear. For my money, and the fact I'm stuck with a can for life, I want it to be as quiet as possible. Again, this is only my opinion that I've derived from expierence.
Now, I've found that an adjustable gas block helps, but doesn't really change timing, just pressure. Gas system length, buffer weight, spring power are more effective ways to time the bolt opening. My favorite barrel to suppress is an 18" with rifle gas. When I put a can on this one, it acts a lot like an 18" mid gas system.
I gotcha, wasn't sure what you meant. I've read before that 300blk specifically sounds better (supersonic) than 223 does. I've also heard repeatedly that 223 is hard to suppress, I think it's just the nature of that round and it being high pressure and being designed for barrels longer than 16". I can shoot supersonic .44 Mag out of a 16" barrel with my Hybrid much more comfortably than I can shoot 223. Makes sense with it being a pistol round the muzzle pressure is probably fairly low at 16", while 223 still has unburnt powder at that length.
I searched and finally found some technical data from testing of muzzle pressures on 223 relative to barrel length. Long story short, the pressure dropped about 6% per inch from 16" to 20". A 24% drop in pressure has to make the silencers job much easier, and moving it further away from your ears helps as well. Plus less pressure in the can means less back pressure = less port pop.
Sorry for getting off in the weeds here, since the OP isn't even shooting .223 but I'm sure barrel length effects all cartridges to some degree.
One of the articles I found, for those like me that are nerdy enough to read such things.
https://ndiastorage.blob.core.usgovcloud...PhilipDater.pdf tag
