300 AAC Blackout vs. 400 THR Knockout!

[BT Sniper]

It was brought to my attention just how much my new caliber looks like a grown up 300 AAC so I grabed some 300 AAC brass I happened to have and compared! WOW the 400 looks like an exact scaled up 300! Fricken cool!

So now the only question now is if somone wanted to lauch HEAVY projectiles quitely (subsonic) just how heavy of bullet will the 400 launch at 1100 FPS? 400 grains? More? Maybe!

Not really what I put the 400 together for but still very cool!

Looking at the pics a bit I should of added a FN5.7x28 into the pic. I bet the three would all look very similar!














Good shooting and Swag On!

BT

[BT Sniper]

Here is the FN5.7x28 added to the picture.

[runfiverun]

neck a 5 seven up to 270 and it looks exactly the same as the 300.
i just done that to a couple hundred today.

[parrott1969]

From the pics, I would say that you all are setting your self's up for problems. Col. Whelen did similar wildcating back in the day and he discovered that once he necked the 06 up past .375 he had headspacing issues. Those pics look very close to what he had.

[DukeInFlorida]

Except for one thing, parott1969........

The 300aac blackout is a proven design. And, BT has already successfully loaded and fired his creation.

[bohica2xo]

Sigh. Every freaking time.

There was no headspace issue with the 400 Whelen

The only head space issue was that people shortcut making some dies, and reduced the diameter of the cases at the shoulder from the Whelen design. Basically the idiots used a 30-06 reamer to make the die body then reamed out the neck for the 400.

We headspace pistol cartridges on the mouth without issue. If the shoulder is in the right place to begin with there is simply no way you could push it back far enough to make a difference with the action of a firearm.
If you could set that shoulder back .015 with a rifle action, we would not have loading presses - we would be pushing cases in to dies with our bare hands.

So, 50+ years ago some bad dies made essentially the wrong cartridge for the chamber. Yet the damn headspace rumor refuses to die.

Here is one man's quest for the truth on this:

http://www.z-hat.com/smashing_the_headspace_myth.htm

Many thanks for board member ogotz for digging that up the last time this rumor surfaced.

B.

[runfiverun]

i'll shorten it up.
there needs to be a shoulder/rim/belt to headspace on.
some idiots chambered some rifles without a shoulder.
and blamed the cartridge design, instead of themselves for not following directions.

[parrott1969]

This runs counter to what Col Whelen was " supposed to have said". I will see if I can dig up the article.

[jimrk]

and let's see the 5.7 to .308 in the 300 AAC blackout

[BT Sniper]

I can do that! Might take a while to prep the pic but sure give me a while, I'll take a pick of a 30 cal bullet made from 5.7 seated in the 300AAC.

BT

[DukeInFlorida]

Brian, you need to concentrate on making customer swage die sets, and put all your own development aside until 2013.




Either that, Or I am moving to where you live, so I can be closer to the "source"


J/K Brian. Good stuff, keep up the good work.....

[BT Sniper]

Yanking my chain again remember all work and no play makes jack a dull boy, All work and no play make Jack a dull boy, all work and no play makes Jack a dull boy, all work and no play make Jack a dull boy,...............etc.......etc........etc.....

It would be entirly possible for me to work on customer orders every single day. Then get more orders to replace the finished ones and so on till one works every day. Got to set aside some me time, and I thought I would share some of my "me time" projects.

As a stay home dad of twin 5 year olds and business going well I got to get a bit of stress relief, don't want to burn out just as things are getting started.

Good shooting

BT

[Hamish]

"As a stay home dad of twin 5 year olds and business going well I got to get a bit of stress relief, don't want to burn out just as things are getting started."

Amen!! Another vendor on this site needs to take that to heart.

BTW- You's jokers need to stop smooshin' perfectly good brass. That just ain't right!

[bohica2xo]

No such thing as perfectly good nine-sillymeter brass - until you mash it in to .451 bullets!

.

[redneckdan]

You should have no problem making 400gr in a .40 I have a 400gr mould for .375 that can be pushed super sonic with a 375 JDJ.