300 whisper info

[CJ]

I am not the expert yet. But I believe the .223 brass has to be cut down a little.

yes, you cut the neck/shoulder off until the case is straight, then you put a slight neck down to .298 I believe.

[Homemade]

Here is a great article on whisper ballistics, reloading, and history.

The 300 Whisper will be a very different story. When its 220 gr bullet hits the ram, it’ll still be going 983 fps. Amazingly, it will have only lost a miserly 67 fps over the 200 meter course! Compare that to the 7 TCU loosing 551 fps at the same distance. Well, you might say, there’s bound to be a lot more wind drift because the bullet is moving so slow. Wrong. That’s not how it works. Wind drift will be only 3.8 inches or 36% less than the 7mm bullet. How about recoil? That big 220 has got to produce a lot more recoil than the 140, right? Wrong again. Recoil comes out to only 6.6 foot pounds - 56% less than the faster, but smaller 140 gr bullet. Momentum knockdown for the Whisper will be .96 pound seconds or 13.5% more push on the target. So here we have a case where you have less velocity loss, Oh, by the way, the Whisper can do all that while delivering a half MOA in accuracy at 200 meters.

Interesting GB auction info http://www.gunbroker.com/Auction/Vie...Item=225427240

[gat0r]

I'm going to guess that they don't grow much given the slight neck, or at least, not as much as .223?

pressure is pretty low as long as your loading subsonic -- didnt have to trim mine on 1st reload. havent had time to shoot a 2nd time yet.

[Homemade]

http://en.wikipedia.org/wiki/300_AAC_Blackout_%287.62x35mm%29

Is the blackout the same as the Whisper?

http://www.ar15.com/forums/topic.html?b=7&f=22&t=850493

[gat0r]

http://en.wikipedia.org/wiki/300_AAC...287.62x35mm%29

Is the blackout the same as the Whisper?

http://www.ar15.com/forums/topic.html?b=7&f=22&t=850493

close but different
neck diameter & case length are slightly larger for blackout.

they had to be just a little different.... just like fireball to whisper
had to be different so Jones wouldn't sue.

if i recall blackout wont work in fireball chamber, dont remember if it will work in whisper

[AnthonyS]

well after reading this topic and doing some internet research, I'm ditching the 6.8 idea and building a 300-221 instead.

The sheer number of 30 cal bullets available for reloading and using standard AR magazines makes this a no brainer for me.

Thanks guys.

[Homemade]

well after reading this topic and doing some internet research, I'm ditching the 6.8 idea and building a 300-221 instead.

The sheer number of 30 cal bullets available for reloading and using standard AR magazines makes this a no brainer for me.

Thanks guys.

before you go 300/221 check out the 300 AAC Blackout. Its slightly bigger than the fireball and whisper, it is also being mass produced (factory brass woohoo). Check out AR15.com, google, and youtube for the full story. Lots of uppers being produced for very reasonable prices. You could also throw any 5.56 BCG in your 300 upper and the savings continue!!

[94StangFiveO]

well after reading this topic and doing some internet research, I'm ditching the 6.8 idea and building a 300-221 instead.

The sheer number of 30 cal bullets available for reloading and using standard AR magazines makes this a no brainer for me.

Thanks guys.

Similar conclusion I came to after making mythread about the 6.8.

[CJ]

Don't all .300 whisper variants work optimally with a pistol gas block location? Or can you get away with a mid length gas block location? Seems like SI Defense only sells them in pistol location. Sure would be nice to use one of those closeout adam arms piston kits.

[Homemade]

Don't all .300 whisper variants work optimally with a pistol gas block location? Or can you get away with a mid length gas block location? Seems like SI Defense only sells them in pistol location. Sure would be nice to use one of those closeout adam arms piston kits.

I believe the 16" cmmg is a carbine length.

Would that work?

When you say whisper .... you're saying all the 300/.223 variants right?

[94StangFiveO]

I believe the 16" cmmg is a carbine length.

Would that work?

When you say whisper .... you're saying all the 300/.223 variants right?

Is that the one you showed me in the other thread? I thought it was listed as .300 Blackout mid-length?

[Homemade]

The primary arms mc300 is a pistol length and the noveske is a carbine length.

With that said it sounds like we need numbers on the pressures required to operate the piston system and what pressures one can expect from the different gas systems... anyone have that info?

[94StangFiveO]

The primary arms mc300 is a pistol length and the noveske is a carbine length.

With that said it sounds like we need numbers on the pressures required to operate the piston system and what pressures one can expect from the different gas systems... anyone have that info?

I completely overlooked that. Makes sense though of why nobody had mid length gas system uppers or barrels.

[Homemade]

http://www.ar15.com/forums/topic.html?b=7&f=114&t=852405

300 blackout brass

[YALE]

Don't all .300 whisper variants work optimally with a pistol gas block location? Or can you get away with a mid length gas block location? Seems like SI Defense only sells them in pistol location. Sure would be nice to use one of those closeout adam arms piston kits.

They have pistol-length kits:

http://www.spikestactical.com/new/z/piston-kit-adams-armsspikes-tactical-pistol-length-p-569.html