300 AAC Blackout contest

[Tozguy]

300 AAC Blackout contest

If the fictitious Institute of Higher Yearning (IHY) offers $100 000 to the first person to shoot 5 consecutive groups of 5 shots that agg .250’’ or less at 100 yds., using the SAAMI 300 AAC Blackout cartridge, with a bonus of $50 000 for doing it with subsonic ammo, what would you use to win the prize? Please include as much detail as possible on the rifle design and ammo components that you would choose.

Fine print: (1) This is a friendly academic contest designed to compare our ideas on how to reach the goal. Contestants may ask questions for clarification but arguing, insults, complaining or criticism may lead to disqualification. (2) A panel of 5 persons will be recruited to rate the different approaches submitted in this thread. The panel will include a reputable gunsmith, a reputable long range shooter, a reputable short range shooter and a bullet technician. (3)Prize money will be paid only if funds are available. (4) Customer service will be available as soon as someone volunteers for that position. (5) The IHY is a figment of the imagination. Any resemblance to a real organisation is purely accidental.

 

[Dusty Stevens]

As fine as the blackout is for its intended purpose of selling tactikool rifles, does it even penetrate the paper at 100? Seriously i put together a model seven with an 11" barrel and suppressor for one of those class 3 type guys and itll do it. His wife uses it to deer hunt believe it or not.

 

[Tozguy]

Hi Dusty,
The development of the 300 BLK is rather interesting. It was standardized by SAAMI in 2011 so I would call it relatively new (even with a history of similar widcats) Also interesting to see that brass and dies are becoming more and more available. I don't think we have discovered everything it can do yet.
It might not be whomping the 30BR in VFS anytime soon but how close can it get?
To my mind, if a 22lr rimfire cartridge can shoot 250-25x at 50 yds with a subsonic 40 gr. bullet then why can't we get a subsonic 30 cal bullet to do the equivalent?
Cheers, Mike

 

[Dusty Stevens]

Can a bullet not be fired fast enough to stabilize?

 

[mshelton]

Let's get a 338ppc shoot going...

 

[Dusty Stevens]

Let's get a 338ppc shoot going...

I want a .416BR

 

[mshelton]

Let's get a 338ppc shoot going...

I want a .416BR

Sorry but I don't think that'll run in a tactiard platform.

 

[ebb]

I read an article on the Rifleman's blog about a guy shooting a 300 BLK in 300 yard competition of some sort that was getting excellent accuracy. You might go to that article to gain some insight about it's accuracy potential. I tend to believe what German Salazar allows to be printed on his blog.

 

[Tozguy]

Thanks EBB, went and read the article. Looks encouraging.

 

[Tozguy]

Can a bullet not be fired fast enough to stabilize?

Not sure what to make of your comment.....

 

[Dusty Stevens]

I was asking if a bullet can be fired so slow it doesnt stabilize. Like a football

 

[broncman]

Of course it can! That is why the charts and programs such as Bergers ask you to input a velocity for the chosen bullet and twist rate.

That is a problem for the Blackout. Most barrels are geared toward stabilizing the heavys. I have ran a lot of ammo through my blackout and the twist rate is too high for optimum accuracy in the 110-125 range of bullets I shoot. I do not shoot the heavies or subsonic. I have quite a few 1/2" five shot groups, but I the norm is 3/4 to 1". It is a 16" Noveske 1 in 8.

Copper fouls pretty fast too.

 

[antitactical]

Neck it down to a .22 and a 14 twist barrel. Then I think you may have something. Maybe a single shot action like a 40x or panda in a short range stock.... 21grs of 4198 and a 52gr bullet. I think i may even call it a .222. Far superior to a 5.56 or .223 in my opinion.

 

[GSPV]

If it was me, I'd treat it somewhat like a 30 BR.

Standard looking VFS configuration

Get a reamer cut with a cleanup neck and zero freebore
Chamber up a slow twist barrel about 22 or so inches
Lapua brass
CCI BR4 primer
BIB 110 bullets
Hodgdon H110'or Lil'Gun powder

I'd start out with about 3 thou of neck tension and the bullet jammed 20 thou. I'd start about 18.5 grains and go up 0.5 till I got a little pressure or ran out of case.
I'd then play around just below that 0.2 at a time looking for something promising.
When I found the right pattern, I'd play with seating depth to tighten things up.
Since this isn't a proven configuration, I'd use a tuner to,hedge my bets on finding a node.

Hope thwt makes sense

 

[Tozguy]

Greg, thanks, that makes perfect sense. Its gonna have a tuner for sure.
Would you venture a suggestion for twist rate?
Published loads lead me to expect around 2200-2300 fps muzzle velocity for a 110 bullet.
Regards, Mike

 

[Tozguy]

Neck it down to a .22 and a 14 twist barrel. Then I think you may have something. Maybe a single shot action like a 40x or panda in a short range stock.... 21grs of 4198 and a 52gr bullet. I think i may even call it a .222. Far superior to a 5.56 or .223 in my opinion.

I know what you mean but I already have a 222R, 223, 6/223 and 6BR.
THAT 300 BLK is giving me tunnel vision. She's one sexy babe even if it turns out she can't cook.

 

[Tozguy]

I was asking if a bullet can be fired so slow it doesnt stabilize. Like a football

I hear you. The question of stabilization has me baffled. A 40gr. 22lr bullet from a 16.5 twist barrel shipping out the muzzle at 1055 fps is only spinning 46 036 rpm but is plenty accurate so must be stabilized. A 115ish bullet from a 17 twist 30BR at 3052 fps is rotating at 129 261 rpm and it is considered marginally stabilized but is more accurate than I'll ever be.
A 7 twist 300 BLK at 1060 fps will spin a bullet at 109 028 rpm. Seems to me that there should be a bullet out there that likes that (but what do I know???) HELP!

 

[GSPV]

Greg, thanks, that makes perfect sense. Its gonna have a tuner for sure.
Would you venture a suggestion for twist rate?
Published loads lead me to expect around 2200-2300 fps muzzle velocity for a 110 bullet.
Regards, Mike

I would go on the Berger site and use their twist rate calculator on their 115 gr match FB. That would give you an idea.

If you plan to hunt with it, I would rather use something like the Nosler 125 gr BT to choose my twist. That way you would have some flexibility.

 

[Geno C]

Sadly the calculator doesn't have that bullet as a choice. Barrel optimized to the light bullets should have no problems printing tiny groups.

 

[Tozguy]

Another aspect of the Berger calculator is that it works best for high BC bullets (ie boattails) They caution us that FB bullets can usually be stabilized with less twist than the calculator will show. For example, the Berger 115 gr match FB target bullet is rated for 19'' twist or faster but the calculator says 13 twist or faster. So there is still some room left for fudging.
I have given up on the subsonic idea but muzzle velocity from the 300 BLK will likely still be on the slower end of the spectrum for this bullet, so I tend towards a 15 twist.
No hunting for this gun. It is going to weigh 10.5 lbs.
How do you see it?