.300 blackout terminal ballistics

[sinlessorrow]

hey guys, i have a custom 10.3" pistol length gas system barrel being made in .300 blackout and im wondering, how does the terminal ballistics out of a SBR compare to that of the 5.56 out of the same barrel length?

[tpd223]

The .300BLK will blow the socks off of the 5.56 from just about any barrel length.

[JasonM]

From a 9" bbl, 300 BLK (123gr) has 37% more muzzle energy than 5.56 (M855)...

Change your ammo to something like the 110 VMax and you've really got a lot of power.

300 BLK shines in SBRs

[TiroFijo]

I'm very familiar with the 300 whisper (we use it a lot around here for IHMSA shooting, and have done so for 12+ years) which is esentially the same round.

No doubt the knockdown power (= momentum, only good for tumbling steel targets) and energy are greater than the 5.56, and brick penetration too.

But what about gel test data?
Fragmentation from several barrel lenghts?
Performance after intermediate barriers?
Velocity threshold?
Best bullets (perhaps depending on specific aplication)?
Hague compliant but still good performing FMJ bullet available?

[JasonM]

I'm very familiar with the 300 whisper (we use it a lot around here for IHMSA shooting, and have done so for 12+ years) which is esentially the same round.

yes, and in a given barrel length, the 300 BLK will have higher velocity than the 300 Whisper®, similar to the .223/5.56 difference.

No doubt the knockdown power (= momentum, only good for tumbling steel targets) and energy are greater than the 5.56, and brick penetration too.

Yes

But what about gel test data?

The true 'defensive' loads are in development and due out this year. Currently, the best widely available loaded defensive/hunting load is the Hornady 300W® 110gr VMax.

One of the new loads uses a Rem 125gr Accutip. From a 9" 300 BLK upper, 12 feet:


Video or 125 and 110:
http://www.youtube.com/watch?v=hRw-ypBgrKo

A review of a bunch of bullets:
http://www.silencertalk.com/300AAC/3...006OCT2010.pdf

Here's a wider review of some bullets/ energy:

http://www.brassfetcher.com/300BLACKOUT ... 7APR11.pdf

Fragmentation from several barrel lenghts?

See above PDF. But, the 762 doesn't rely on fragmentation like the 5.56 does. With the 300 BLK, expanding, deep penetrating bullets are more the goal.

Performance after intermediate barriers?

Run of the mill with current ammo, but barrier blind loads are in development

Velocity threshold?

Depends on the bullets and what you want them to do.
Robert's discussion of max effective range:

http://www.silencertalk.com/forum/vi...?f=128&t=71271

Best bullets (perhaps depending on specific aplication)?

Very much application-dependent, but in general, currently, the 110 VMax and 125 Accutip, also I'd look at: http://barnesbullets.myshopify.com/p...grain-tac-x-fb

Hague compliant but still good performing FMJ bullet available?

There are 2 new FMJ bullets coming out this year, slated for Sept last i heard, one FMJ and one OTM. Both legal.

[TiroFijo]

Wow, Jason!

This is as comprenhensive a reply as they come, thanks a lot

Now thinking about reaming the lead/throat area in the old 300 whisper chambers... can shoot both.

What do you feel is the best niche for this round?
SBR rifles for CQB and up to what ranges?

Thanks in advance.

Ruben

[JasonM]

Wow, Jason!

This is as comprenhensive a reply as they come, thanks a lot

Now thinking about reaming the lead/throat area in the old 300 whisper chambers... can shoot both.

What do you feel is the best niche for this round?
SBR rifles for CQB and up to what ranges?

Thanks in advance.

Ruben

Glad to help Ruben.

An important thing to remember in regards to the 300 BLK is that it is very much still in its infancy. It was announced less than a year ago and lots of exciting development is upcoming.

Yes, you can certainly have your chambers reamed and then be able to shoot any and all ammo safely. There are a number of companies that will do this for a minimal fee, or you can buy your own reamer.

My PERSONAL feeling about this round and rifle is that the primary niche is hunting or defense use (ideally in an SBR) from CQB out to 250m (with supersonic ammo).

It can go a lot further than that of course- Robert tested the supersonic ammo and it remained supersonic out past 600m, but it is not designed to be a long range round... you'll have to move up to 308, 260, etc for that.

It SHINES in very short barrels where traditionally the 5.56 has lacked power and had too much flash/blast. It is downright gentle on suppressors compared to the 5.56. AND it has factory subsonic ammo that will cycle an AR.

It also has a very important application as far as offering a 30-cal solution for ARs for hunting. Not to mention being able to build up a very compact and light bolt gun for hunting.

And, at the end of the day, if you decide it's not for you, just switch barrels and you've got a great 5.56 setup.

YMMV of course


The response and support for it has been great so far:

Publicly announced:

AAC - uppers, rifles, silencers, and ammunition.
Adams Arms - rifles and uppers.
AR-Stoner - barrels.
AR15 Performance - barrels.
Atlanta Arms - ammo.
Barnes Bullets - bullets.
Black Hole Weaponry - barrels.
Brad's Warehouse - converted brass.
Bushmaster Firearms - uppers and rifles.
BWE Firearms - rifles, uppers, and suppressors.
CMMG - barrels, uppers, and ammo.
Compass Lake Engineering - AR barrels.
Cor-Bon - ammo
Delta Company Arms - rifles, barrels, uppers.
Dillon Precision - reloading conversion kits.
Double Tap - ammo.
DPMS - rifles and uppers.
Forster - reloading dies.
Hornady - ammo, dies.
Lee - reloading dies.
Lewis Machine and Tool - barrels, uppers, rifles.
Loki Weapon Systems - uppers/rifles.
Lone Star Armory - 300 AAC BLACKOUT marked lowers.
Lothar Walther - barrels.
Match Grade Machine - Thompson barrels.
McGowen Barrel - Savage and other barrels.
Montana Rifleman - barrels.
Noveske - rifles and uppers.
One Shot - ammo.
Pac-Nor - barrels.
Pacific Tool and Gauge - reamers and gauges.
PNW Arms - ammo.
Primary Weapons Systems - rifles and uppers.
Raven Armament Company - ammo and uppers.
Redding - dies.
Remington - ammunition.
Satern Custom Machining, Inc. - barrels.
Selph Arms LLC - barrels, uppers, re-chambering, and rifles.
SI Defense - barrels.
Sierra - bullets.
SilencerCo - silencers.
Southern Ballistic Research - ammo.
Southwest Ammunition, LLC - ammo.
Spike's Tactical - uppers and rifles.
Surefire - 300 BLK sound suppressor.
The Bullet Works - bullets and ammunition.
Triton Arms - AR barrels.
Umlaut Industries - 300 BLK caliber marked Rifles, Upper and Lowers. 16" and 10" Factory Title II.
White Oak Precision - AR barrels.
Wilson Combat - rifles, hunting and self defense ammunition.

Not yet public:

Rifle Company F
Rifle Company G
Ammo Company K
Accessory Company I
Accessory Company J
Accessory Company K

[Ironman8]

Jason,

Some of the draw to having a 5.56 SBR (or any length barrel for that matter) over say 7.62 is the fact that there is less recoil and allows for faster follow-up shots and target transitions. Where does the 300 BLK fall in the recoil category compared to these two?

[JasonM]

Jason,

Some of the draw to having a 5.56 SBR (or any length barrel for that matter) over say 7.62 is the fact that there is less recoil and allows for faster follow-up shots and target transitions. Where does the 300 BLK fall in the recoil category compared to these two?

yes. 300 BLK (in my experience) falls inbetween the two, but closer to 5.56. The supersonic rounds definitely have more push than 5.56, but it's nowhere near a 7.62 carbine.

A can, or muzzle device can counteract this of course. But i don't find it to be bad.

[JasonM]

Jason,

Some of the draw to having a 5.56 SBR (or any length barrel for that matter) over say 7.62 is the fact that there is less recoil and allows for faster follow-up shots and target transitions. Where does the 300 BLK fall in the recoil category compared to these two?

Actually, i find the reduced muzzle blast/concussion versus 5.56 (in SBRs) to counteract differences in recoil.