Re: Blackout or whisper
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rsilvers</div><div class="ubbcode-body">The BLACKOUT chamber was actually developed based on setting the throat so that you can load the 220 or 240 Sierra to 2.26 OAL and have a 0.010 jump to the rifling. Jamming the bullet can give unpredictable startup pressure.
It also gives additional velocity potential with full power ammo, compared to a Whisper(R) chamber.
The point of full power ammo is it can way outperform 5.56mm up close for QCB, home defense, and hunting. Remington 125 grain AccuTip ammo will be awesome. It has been tuned to 12-18 inches of 10% gel penetration from 50+ yards away.
If you don't ream your chamber, factory subsonic ammo may go supersonic more easily due to the higher pressure. That may be why this guy gave the ammo a 1-star review after it went supersonic in his undisclosed rifle which may or may not have a bore that is below SAAMI minimum in cross-sectional area:
http://www.midwayusa.com/viewproduct/?productnumber=856618
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Actually that was me. I had a problem with the ammo going super sonic.
My rifle is a Rem 700 that was converted from 17fireball to 300BLK with a Factory AAC BBL. I have been getting supersonic cracks with the remington ammo and not the corbon whisper ammo.
I do not have a working chrony at this time so I cannot tell you exactly what the FPS is, but my ears don't lie.
Also there are some others on a different forum getting the same results.
I am currently waiting for Rem to send out a replacement for my case of ammo.