.556 or 300 Blackout

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[ARCHIVED THREAD] - .556 or 300 Blackout

Posted: 8/20/2014 7:54:03 AM EDT

I am planning my first build and I want to build a AR 15 pistol with a 10.5" barrel. I am trying to decide if I should make it a .556 or a 300 Blackout. I am leaning towards .556 only because of how easy it is to find .556 55 grain rounds and they are cheaper than 300 Blackout. I want to know if there are any reasons I should consider a 300 Blackout instead though. If I am going to put the money into a quality build than I want to choose the right caliber for it. Any thoughts?

Posted: 8/20/2014 8:08:21 AM EDT

[#1]

300 is badass, but it's still a rich man's boolit. I'll wait till its more mainstream.

Posted: 8/20/2014 8:10:47 AM EDT

[#2]

6.8
/thread

Posted: 8/20/2014 9:02:50 AM EDT

[#3]

Both....

Posted: 8/20/2014 9:59:27 AM EDT

[#4]

5.56 or build an AK varient pistol in 7.62x39.

Posted: 8/20/2014 11:37:17 AM EDT

[#5]

For your first, 5.56 would be my suggestion. As stated, the cost to shoot is much lower. Adding a 300 Blackout to your quiver might be in your future but only if you reload. My next builds are 9mm, .308 and then 300 Blackout in that order. I have six in various forms of 5.56. Still undecided about a .22...dedicated or an upper. Good luck. Can you feel the itch starting? Infection has begun.

Posted: 8/20/2014 12:07:17 PM EDT

[#6]

I love my .300 blackout. But I reload and it still is not a cheap round to make. .223 if you are going to shot a lot or reload if you want a black out.

Posted: 8/20/2014 12:21:54 PM EDT

[#7]

Ok that has been helpful. I have one more question regarding 5.56 vs. 300 Blackout. Can I expect to have problems shooting 5.56 out of a short barrel while operating under a gas system? Is there anything I need to know about this since 5.56 was made for a full size barrel originally.

Posted: 8/20/2014 12:27:54 PM EDT

[#8]

If you're not into reloading yet then .300 AAC BLK is as good an excuse as any.

I only have one AR pistol and it is in .300 AAC BLK. I see you're on Ohio guy - if you find yourself near Wayne County let me know and you can test drive my rig.

For short barrels the .300 AAC BLK is just head and shoulders better than 5.56. If you envision your AR pistol as being anything other than a toy, get it in the right caliber.

Posted: 8/20/2014 12:38:48 PM EDT

[#9]

Quote History

Quoted:

Ok that has been helpful. I have one more question regarding 5.56 vs. 300 Blackout. Can I expect to have problems shooting 5.56 out of a short barrel while operating under a gas system? Is there anything I need to know about this since 5.56 was made for a full size barrel originally.

View Quote

5.56 works fine in short barrels. My 10" SBR runs great suppressed and unsuppressed.

Posted: 8/20/2014 12:45:07 PM EDT

[#10]

Go with the 5.56 for your first build.....plenty of ammo, cheaper rounds!

Also, I'm guessing since this is your first build you don't have a suppressor.......? Well thats the main fun of a .300 blackout is to run it suppressed...... just saying. I have both and love my 300 blackout pistol..... hopefully soon to be SBR, but I run a .30 cal suppressor on it and that is where its at.

Posted: 8/20/2014 12:56:09 PM EDT

[#11]

Ok sounds good. No I don't have a suppressor yet but it's in the works. Are there any downfalls to running a SBR on a gas system vs. a piston system?

Posted: 8/20/2014 1:51:55 PM EDT

[#12]

Quote History

Quoted:

For your first, 5.56 would be my suggestion. As stated, the cost to shoot is much lower. Adding a 300 Blackout to your quiver might be in your future but only if you reload. My next builds are 9mm, .308 and then 300 Blackout in that order. I have six in various forms of 5.56. Still undecided about a .22...dedicated or an upper. Good luck. Can you feel the itch starting? Infection has begun.

View Quote

You NEED a 22lr. They're fun as hell and cheap as hell to shoot as well...

Posted: 8/21/2014 8:26:50 AM EDT

[#13]

Quote History

Quoted:
If you're not into reloading yet then .300 AAC BLK is as good an excuse as any.

I only have one AR pistol and it is in .300 AAC BLK. I see you're on Ohio guy - if you find yourself near Wayne County let me know and you can test drive my rig.

For short barrels the .300 AAC BLK is just head and shoulders better than 5.56. If you envision your AR pistol as being anything other than a toy, get it in the right caliber.

View Quote

This only applies if you use a barrel shorter than 11.5" and use M885 or M193. There is plenty of modern ammo that are ballistically effective in barrels as short as 10.3"

Posted: 8/21/2014 8:31:43 AM EDT

[#14]

Quote History

Quoted:
This only applies if you use a barrel shorter than 11.5" and use M885 or M193. There is plenty of modern ammo that are ballistically effective in barrels as short as 10.3"

View Quote View All Quotes

View All Quotes

Quote History

Quoted:

Quoted:

If you're not into reloading yet then .300 AAC BLK is as good an excuse as any.

I only have one AR pistol and it is in .300 AAC BLK. I see you're on Ohio guy - if you find yourself near Wayne County let me know and you can test drive my rig.

For short barrels the .300 AAC BLK is just head and shoulders better than 5.56. If you envision your AR pistol as being anything other than a toy, get it in the right caliber.

This only applies if you use a barrel shorter than 11.5" and use M885 or M193. There is plenty of modern ammo that are ballistically effective in barrels as short as 10.3"

10.3" barreled 5.56 rifles have seen far more combat than .300 blackout has - and probably more than they ever will. Incidently M855 is normally used.

Personally I have a 10" 5.56 and use 75gr TAP.

Posted: 8/21/2014 9:16:00 AM EDT

[#15]

.223/5.56 for first build. If you already have a .223 with a longer barrel, consider building a 9mm AR pistol.

Don't do .300 unless you reload.

Posted: 8/21/2014 4:51:38 PM EDT

[#16]

Quote History

Quoted:
10.3" barreled 5.56 rifles have seen far more combat than .300 blackout has - and probably more than they ever will. Incidently M855 is normally used.

Personally I have a 10" 5.56 and use 75gr TAP.

View Quote View All Quotes

View All Quotes

Quote History

Quoted:

Quoted:
If you're not into reloading yet then .300 AAC BLK is as good an excuse as any.

I only have one AR pistol and it is in .300 AAC BLK. I see you're on Ohio guy - if you find yourself near Wayne County let me know and you can test drive my rig.

For short barrels the .300 AAC BLK is just head and shoulders better than 5.56. If you envision your AR pistol as being anything other than a toy, get it in the right caliber.

This only applies if you use a barrel shorter than 11.5" and use M885 or M193. There is plenty of modern ammo that are ballistically effective in barrels as short as 10.3"

10.3" barreled 5.56 rifles have seen far more combat than .300 blackout has - and probably more than they ever will. Incidently M855 is normally used.

Personally I have a 10" 5.56 and use 75gr TAP.

Agreed, I mentioned M193 because ( according to charts) a 10.3" will get it up to "yawing" speed at the muzzle and hold it for about 50 yards. I figured M855 would not fare much better for soft targets, I stand corrected. I use Speer GDSP 64g , Hornady TAP 75g and MK262 77g in my 10.5" and 12".

Posted: 8/21/2014 9:41:01 PM EDT

[#17]

I saw a 7" barreled pistol in 5.56 run like a raped ape earlier today. It was a glorious thing to behold. Wow, what a difference an H2 buffer makes.
Still trying to figure out what ammo to keep in it for "just in case" events.

[ARCHIVED THREAD] - .556 or 300 Blackout

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