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gauraprema
November 20, 2017, 23:56
Im considering buying a 300 blk AR but I dont know anything about them.Would thosewho know help me out with some info as to how they mix with a standard AR as far as magazines and upers and lowers combining ect...Help please.Recomendations are appreciated.

Stoney
November 21, 2017, 01:31
just don't screw up and put a 556 in by accident

Right Side Up
November 21, 2017, 01:33
I built one a couple of years ago. Ho-Hum groups, so don't shoot it.

For light bullets like the 110 V-Max (which I shot a deer with) standard mags work. For the 220 grain subsonic stuff you need a different mag.....or so I'm told. I don't shoot subs in mine.

paulb2112
November 21, 2017, 04:40
It is really quiet with a can.

Tuhlmann
November 21, 2017, 06:34
Im considering buying a 300 blk AR but I dont know anything about them.Would thosewho know help me out with some info as to how they mix with a standard AR as far as magazines and upers and lowers combining ect...Help please.Recomendations are appreciated.

The only thing you gotta do is just swap a barrel on any upper or a swap out a complete upper and go. By design 300 BLK is supposed to take the same bolt, buffer, and magazine as 5.56. Some guys run into problems with mags, but I think that comes from handloading subs and not maintaining COAL, but perhaps some mags/mag followers are fussy. Hasnít been my experience, though.

Uppers should be built with a pistol length gas system if you ever plan to shoot subsonic, or you will have a single shot. Not sure what is the longest acceptable gas length with supers, but Iíd stick with the original design and avoid creating conflict where none currently exists.

Good luck, I think youíll find itís a useful, versatile, and capable chambering if you donít go trying to reinvent the wheel.

yovinny
November 21, 2017, 08:26
Mine is no target rifle, but for a $89. Barrel I cant complain much.
It also seems to shoot anything I stuff in to the same exact windage zero with just a difference in elevation, so it makes switching loading around very easy.
I only do supersonic and mostly shoot cast bullets, so its about as cheap as shooting a 9mm, but way more versatile and fun..:)
Its not the latest-greatest some make it out to be,, but think of it as just an updated modern day 30 carbine and I think you'll be very pleased....:)

gentlemanjoe
November 21, 2017, 09:03
I have 2. One I shoot suppressed with 220 grains and one I shoot supersonic with 147 grains . All of the components are the same as a 5.56 with the exception of the barrel. The norm is to use pistol length uppers as opposed to carbine or rifle length as all of the gases are consumed with 8,5-10" barrels as I understand it.

With subs mine will shoot minute of pig at 175 yards (220 grain drops fast beyond 150 yards) and with supers minute of man at 350. As mentioned they are not DMR's

Type in .300 AAC Kaboom and you will understand why segregating your ammo is critical. I've never had it happen because I keep everything separate, magazines are marked either sub or super and the uppers are engraved .300 AAC.

Firing the 556 in a .300 upper is not nearly as spectacular as firing a .300 in a 5.56 upper. It's hard to squeeze that .30 caliber thru a .22 caliber hole and the results of trying are like holding a grenade next to your face.

This guy had a great idea of marking rifle and mags. They are basically thick industrial rubber bands marked appropriately. I swung down the trigger guard and put the red ones around the magwell and use either yellow or red to mark magazines as subs or supers.

https://www.ebay.com/sch/live2prep/m.html?item=131909658909&ssPageName=STRK%3AMEBIDX%3AIT&rt=nc&_trksid=p2047675.l2562

wanneroo
November 21, 2017, 09:47
300 BO is a lot of fun. You can do a lot with it and after a few years I am still learning. I find it plenty accurate but of course it's more a short range round, even though there are folks like a friend of mine who shoots them long distance out to 600-700 yards.

Really to get the most out of it and not spend a fortune you need to reload for it. Factory ammo has come down in price but is still pricey. One of my favorite loadings is a 147 or 150 grain FMJ for target plinking. I'm a spendthrift buy only on sale buy in bulk reloader so I hoover up good deals in bulk when I can get them. Right now reloading a 147g FMJ is running me just over 20 cents a round.

Impala_Guy
November 21, 2017, 09:54
300 AAC uses the same magazines and bolt groups as 5.56. I run an Aero .300 blackout upper with a carbine length gas tube on one of their lowers with standard M4 buffer assembly and have had no problems with a case of S+B ammo I have been slowly working down. I have a shit ton of 150 grain 30 cal bullet pulls and some H110 I plan on reloading with, though the heavier bullets do cut into velocity and range. I use a combination of magpul and Israeli M16 milsurp aluminum mags. I run a cheap PSA 5.56 upper occasionally on the same lower with no problems, although I use a dedicated bolt group for that one

Fun round whose smaller case diameter seems more practical to me than 7.62 X 39 AR15 bolt group and magazine systems, although the 300 AAC is slightly less powerful than the Soviet round. I've hunted with it a couple of times but haven't had a deer walk out when I had it in hand.

Stoney
November 21, 2017, 12:56
thought about getting one, but went with x39, it will go subsonic with 208gr and 10 gr of 2400, plus it shoots cheaper ammo.

Falfan2017
November 21, 2017, 13:01
thought about getting one, but went with x39, it will go subsonic with 208gr and 10 gr of 2400, plus it shoots cheaper ammo.

This was my thought as well. I built a 7.62x 39 pistol. It runs perfect with the cheapest steel case ammo. With a 10" barrel it does about 2350 fps with 123 gr so very little loss of velocity from a rifle. Only thing is you need a 7.62x39 bolt and mags. C products makes great mags.

John A
November 21, 2017, 14:54
The blackout is somewhat of an enigma.

With supersonic bullets, they shoot about like an AK47 (7.62x39)'ish ballistics.

With subsonics and a suppressor, they shoot about like a 45acp'ish ballistics.

These really were tasked with too much expectations. Kind of a jack of all trades, master of none mindset.

Many people will need to use an adjustable gas block to use both supers and subs from the same gun.

I was rather disappointed in how it sounded suppressed at first. Even with commercial subsonic ammo and a good suppressor sounded more like someone banging two garbage can lids together.

It took me quite a while to work up a load that was both quiet and cycled flawlessly and that's how I keep it now. If I want something that shoots about like an SKS, I'll use an SKS and save a ton of money on ammo.

I finally made a dedicated integrally suppressed upper for it and after all is said and done, I love it.

Just don't expect the blackout to live up to all the hype straight out of the box.

That's why I opened up my reply how I did. The blackout is somewhat of an enigma.

It has a lot of potential. But depending on your expectations and determination, may or may not be what you want to deal with.

jhend170
November 21, 2017, 15:31
Might as well build or buy an SBR or pistol. You get 95% of the possible velocity by 10.5" of barrel, so unless you have to build a rifle in your area it's more of a wasted weight to carry around.

My 10.5' with a Bergara barrel is managing less than 2moa, which for the effective range of the round is plenty good enough. You'll only want to hunt to maybe 300yds with one, so 2moa at 300yds works out to about a 6" circle. Considering mine was built with swine of the 2 and 4 legged variety in mind 2moa was plenty good. Heck I haven't even worked up a real accurate load yet. Maybe someday, but as long as the pigs keep dropping I'll keep things the way they are.

FYI I've built an a SanTan ambi receiver, running an Adams Arms lightened piston kit, with an RDS and a swing-away 6x. Since it's legally a pistol I just use a crutch foot on the back of my buffer tube. Recoil is light and that works just fine. Makes for a really nice compact (25") , light (~6bls) package that hits with authority inside 200yds.

One last thing... if you reload the BO brass is easily converted from 5.56/.223. What I do is inspect my 5.56 brass for any neck splitting or damage, and if it is it gets converted. Waste not want not.

Shootability
November 21, 2017, 15:42
I have one and never shoot it - you can kill a deer and some kill pigs but my 308 is such a better choice and the accuracy was never impressive.

Interesting but skip it.

hueyville
November 21, 2017, 18:36
Only 300 BO I would want is a short barrel SIG MCX Rattler. Am researching best way to build a knock off but otherwise it really only excells as a heavy bullet subsonic cartridge for suppressors. Friend hog hunts with a suppressed bolt action in 300 BO with 220 grain Barnes bullet but don't know powder he uses. It is set up with a I.R. day/night vision digital scope and is almost movie quiet. If have a specific use for it then jump in. I built two, neither did what wanted and sold barrels before had 100 rounds down bore of each. If I can't knock off a Rattler or pony up $2,000 bucks won't have another 300 as too many other options that meet my particular needs.

wanneroo
November 21, 2017, 19:00
300 AAC uses the same magazines and bolt groups as 5.56. I run an Aero .300 blackout upper with a carbine length gas tube on one of their lowers with standard M4 buffer assembly and have had no problems with a case of S+B ammo I have been slowly working down. I have a shit ton of 150 grain 30 cal bullet pulls and some H110 I plan on reloading with, though the heavier bullets do cut into velocity and range. I use a combination of magpul and Israeli M16 milsurp aluminum mags. I run a cheap PSA 5.56 upper occasionally on the same lower with no problems, although I use a dedicated bolt group for that one

Fun round whose smaller case diameter seems more practical to me than 7.62 X 39 AR15 bolt group and magazine systems, although the 300 AAC is slightly less powerful than the Soviet round. I've hunted with it a couple of times but haven't had a deer walk out when I had it in hand.

Didn't have any luck with 147-150g FMJs and H110. H110 likes lighter bullets. Lil Gun works a lot better for those, at least it did for me.

spider991
November 21, 2017, 20:18
Barnes tac-TX 110g are a friggen beast.....120s are OK but the 110 opens in balistic gel like a flower, 4 petals huge...bad medicine up to 250-300 yards out of a 8.3 in barrel. Runs like a raped ape out of spikes full auto. Lancer or pmags. Interceptor for the best fragible on the market..

KoKodog
November 21, 2017, 23:13
it has been proven that the pistol length gas system is the best choice, while carbine length will work you are rather limited with ammo, loads and reliability


as far as supersonic;

the .300 AAC Blackout really shines w/ the 110 grain Barnes TAC-TX # 30321, this part number is made for the effective speed range of the Blackout, there is another .30 cal 110 grain TAC-TX but it is meant for a higher speed application

now for subsonic;

the .300 AAC Blackout really shines w/ 200 grain and heavier subs, as others have stated, very quiet w/ a can if you have one

on keeping ammo separate;

I only use aluminum GI mags for 5.56, .300 Blackout only goes in Lancer mags, no exceptions !

30 cal round in a standard AR receiver

basically equals the 7.62x39 round

no heavily curved mags

same cartridge base size as 5.56 so no weakened bolt

go from subs to supers by just a mag change
(provided your can will handle both)

lots of bullet choices in .30 cal

decent velocity from a short barrel

its not a do all end all but it does make a good compromise

Tuscan Raider
November 22, 2017, 00:30
Are you rich or have a lot of time to reload?

If you have a suppressor you meet half the argument points.

hueyville
November 23, 2017, 09:20
The blackout is somewhat of an enigma.
With supersonic bullets, they shoot about like an AK47 (7.62x39)'ish ballistics.
With subsonics and a suppressor, they shoot about like a 45acp'ish ballistics.
These really were tasked with too much expectations. Kind of a jack of all trades, master of none mindset.
Many people will need to use an adjustable gas block to use both supers and subs from the same gun.
I was rather disappointed in how it sounded suppressed at first. Even with commercial subsonic ammo and a good suppressor sounded more like someone banging two garbage can lids together.
It took me quite a while to work up a load that was both quiet and cycled flawlessly and that's how I keep it now. If I want something that shoots about like an SKS, I'll use an SKS and save a ton of money on ammo.
I finally made a dedicated integrally suppressed upper for it and after all is said and done, I love it.
Just don't expect the blackout to live up to all the hype straight out of the box.
That's why I opened up my reply how I did. The blackout is somewhat of an enigma.
It has a lot of potential. But depending on your expectations and determination, may or may not be what you want to deal with.

And why I don't have a 300 BO currently. Have a pair of suppressed 45 acps, pair of suppressed 308's with one that cycles subs easily with quick gas change and a 6.8 fast twist barrel that is suppressed and lobs 220 grain subs like a champ. Everything the 300 BO does have something else that does it better. But if the SIG Rattler was not over $2k it would be in my briefcase right now. With no buffer system it's freaking tiny and it's piston drive is 100% reliable. An enigma in itself, it's the gun that the 300 BO was designed to run in. Know one freak that carries a SIG Rattler concealed with strap over shoulder and can have it out from under jacket and in action in about two seconds without opening stock, under four seconds if fools with the stock and then he is deadly out to 150 yards. I want one almost bad enough to pay the entry fee.

John A
November 23, 2017, 10:33
I can understand why you don't particularly have a need for the blackout Huey.

I was dead set against it out of principle for many years, due to Rsilvers specifically. But, all that is off topic.

I wanted the blackout for a good suppressed HD gun, which it is. Now.

Also for brush hunting whitetail at our cabin, which it is.

It probably sounds like I bash it more than I like it, but that's not exactly the way it is.

But going by a lot of what I read on the internet, I was seriously let down and not happy with it at first.

I knew the potential was there and just didn't give up on it, and now am really content with it.

https://www.youtube.com/watch?v=rZR4Mbhf0h0

wanneroo
November 23, 2017, 11:02
The whole 300 BO thing only really caught fire about 5 years ago so I think people are still learning how to best optimize it.

I recently bought some of the CFE BLK powder so we'll see how that goes.

abbynormal
November 30, 2017, 19:10
Shot a SBR .300 Blackout last weekend at 50 yds with an Eotech. Buddy had 147 gr Sierras and was working up a load. With Eotech we were keeping about a 4" group at 50 yds.

Recoil is interesting, to me it seems to have a longer duration than a 5.56 and you can tell you are shooting a much heavier bullet, but it's still comfortable to shoot.

CG&L
November 30, 2017, 20:03
Something's wrong if you're getting 4" groups at 50yds. My dedicated subsonic will get 1" groups at 50yds and my supersonic guns get less than 1" at 100yds.

wanneroo
November 30, 2017, 21:03
Shot a SBR .300 Blackout last weekend at 50 yds with an Eotech. Buddy had 147 gr Sierras and was working up a load. With Eotech we were keeping about a 4" group at 50 yds.

Recoil is interesting, to me it seems to have a longer duration than a 5.56 and you can tell you are shooting a much heavier bullet, but it's still comfortable to shoot.

I find the 147g to 150g load very pleasant to shoot and a few novice shooters I have introduced to shooting seem to like it better than the louder POW of 5.56.

raubvogel
December 09, 2017, 07:41
https://nordiccomp.com/categories/nordic-ar-components-special/

If you want to do it on the cheap

yovinny
December 09, 2017, 10:01
Something's wrong if you're getting 4" groups at 50yds.

Agreed,,even my $69. Anderson blem barrel will hold to about an inch at 50yds with most any type ammo..

I really dont understand the common thoughts of the BO being expensive to feed...?

Maybe if your feeding it strictly factory fodder or even reloads using top shelf Barnes bullets, but their are tons of other less expensive choices, to say nothing of its about the perfect rifle caliber for cast bullets.
IIRC, I reload and shoot something like 27 calibers...I would say the BO is most likely THE cheapest rifle caliber I reload for...

tac-40
December 09, 2017, 14:23
I got started in the 300 BO craze back when it was the Whisper™. Best I could do with 147-150 gr bullets was 1900 fps out of a 16" barrel. The 110 and 125 bullets got bumped up to around 2100-2200 fps before exhibiting signs of pressure. With both loads, blowing primers in the USGI brass was common. Never did see the need for that cartridge that couldn't be done with a more efficient one available at the time, especially one that would work 100% of the time with hitches in its giddyup.

Still feel that way today and still do not have one in my stable.

K. Funk
December 10, 2017, 14:40
I am still working on mine and have some cans ordered. What has my interest is the Remington 700 I bought a while back. Once I get to work on this, I am anxious to see what I can do sub-sonic wise when functionality of a semi-auto gas system is not an issue. Ideally, I can work up a subsonic load that works well in both the AR and Remmy 700.

krf

wanneroo
December 10, 2017, 17:56
I am still working on mine and have some cans ordered. What has my interest is the Remington 700 I bought a while back. Once I get to work on this, I am anxious to see what I can do sub-sonic wise when functionality of a semi-auto gas system is not an issue. Ideally, I can work up a subsonic load that works well in both the AR and Remmy 700.

krf

Having shot a suppressed Rem 700 in 308 with subsonic ammo, I was pretty impressed how quite it all is. Some time down the road I'd definitely look at the 300 BO version with the threaded barrel. I think it would be perfect for pest eradication within 50-100 yards.

hueyville
December 10, 2017, 21:53
300 Win Mag, 308 and 300 BO loaded subsonic are the same round just more empty case capacity to deal with. Have so many 308 factory and handloads that run perfectly subsonic I see no need for a 300 BO plus if need to juice it up for some real power the 308 gives me huge headroom. My short barrel FAL is running fine subsonic with correct gas plug and 240 grain Woodleigh or SMK's. 30 caliber at a set velocity is same thing no matter parent case. Right now it's adjusted and running Tubbs Absolute 2 Hole 350 grain dual projectile ammo. At 350 grains subsonic still hits like a truck.

Stoney
December 11, 2017, 00:17
I need to try some subs in my FAL

Texas Jaguar
December 11, 2017, 02:07
300 Blackout and 300 whisper are both based on the Remington .221 brass case expanded from .224 to .308. According to Hornady they are interchangeable with one another.

yovinny
December 11, 2017, 08:53
300 Blackout and 300 whisper are both based on the Remington .221 brass case expanded from .224 to .308. According to Hornady they are interchangeable with one another.

Yes, but most all brass in use today is made from once fired LC 5.56.
You can DIY, but their are a bunch that convert and sell as ready to load brass for about a dime a rd...which when you figure brass, tooling and time, is really hard to beat...

KoKodog
December 11, 2017, 08:53
300 Blackout and 300 whisper are both based on the Remington .221 brass case expanded from .224 to .308. According to Hornady they are interchangeable with one another.



they are very close to one another but are not truly interchangeable

the .300 Blackout is a SAAMI cartridge, whereas the .300 whisper is a proprietary wildcat from J.D.Jones, he owns the rights to it, and not being SAAMI rated there are no less than 3 chamber reamer specs for it making it rather difficult to be able to claim true interchangeability

while you can fire some whisper cases in a blackout, the reverse is not true

Hornady has no damn business claiming interchangeability, that is a huge lawsuit just waiting to happen, as if the left leaning idiots need help bringing stupid lawsuits to screw with everyone

yovinny
December 11, 2017, 08:59
they are very close to one another but are not truly interchangeable

the .300 Blackout is a SAAMI cartridge, whereas the .300 whisper is a proprietary wildcat from J.D.Jones, he owns the rights to it, and not being SAAMI rated there are no less than 3 chamber reamer specs for it making it rather difficult to be able to claim true interchangeability

while you can fire some whisper cases in a blackout, the reverse is not true

Hornady has no damn business claiming interchangeability, that is a huge lawsuit just waiting to happen, as if the left leaning idiots need help bringing stupid lawsuits to screw with everyone

I believe they only say the loading data is interchangeable , not the cartridges..

hueyville
December 11, 2017, 10:00
I need to try some subs in my FAL

Heavier the better, have to adjust gas if not use a plug with port opened up. Tubbs Absolute 2 Hole with two projectiles totalling 350 grains in weight cycles super well due so much mass of projectiles. The front projectile has a hollow base in which nose of second nests into. Every squeeze of trigger puts two rounds on target and usually hit within an inch of each other out to 75 yards and two inches of each other out to 125 yards. Also have some 250 grain subsonic frangibles from another specialty vendor that cycle o.k.

How would you like to get thumped with this???

http://www.thefirearmblog.com/blog/wp-content/uploads/2017/03/Duplex-Absolute-2-Hole-660x400-660x400.jpg

Tubbs makes it in both subsonic and supersonic now due to popularity of the subsonic version. Be sure which your buying but it's what is in my suppressed 16" short gas FAL and while bigger and bulkier than a 300 BO it's super quiet right up till bullets hit target (big slap like baseball bat hitting watermelon) and cycles better than any other off the shelf subs have tried.

KoKodog
December 12, 2017, 16:04
I believe they only say the loading data is interchangeable , not the cartridges..

much of the load data is, and hopefully they make that clarification as load data only

and funny thing is a lot of .45 acp load data works for .300 blackout too, but you must be wise enough to pick and choose :wink: