300 blk out and .223 components and data

[nammac]

I still have to build my 300 black out. Heck I'll probably have rounds worked up before I get it built

Heck, got it build, now I need to build rounds that it likes...

 

[Ura-Ki]

Watching! I'm looking for a good load for the SBR 10.5 Inch 1/8 Wylde and a .300 B.O. is on the short list!

 

[nammac]

Hey @11Charlie there's a Bushmaster in .300 Blackout already built, for sale here
WTS/WTT OR - NIB BUSHMASTER MINAMALIST IN .300 BLACKOUT PRICE REDUCED

 

[v0lcom13sn0w]

Watching! I'm looking for a good load for the SBR 10.5 Inch 1/8 Wylde and a .300 B.O. is on the short list!

you want a supersonic or subsonic load? i have both. i can text it to you

 

[v0lcom13sn0w]

Heck, got it build, now I need to build rounds that it likes...

View attachment 554068

im a big fan of Accurate 1680 powder....its what AAC recommends for supers and subs....you know..AAC, they invented the round...

 

[nammac]

im a big fan of Accurate 1680 powder....its what AAC recommends for supers and subs....you know..AAC, they invented the round...

This is good to know, hadn't encountered that in my fledgling research. Now I have a direction, thanks for the heads up

 

[v0lcom13sn0w]

This is good to know, hadn't encountered that in my fledgling research. Now I have a direction, thanks for the heads up

for sure man feel free to PM with any questions. i started a thread a long while ago about my quest to make subsonic 300blk

300Blk subsonic

 

[nammac]

for sure man feel free to PM with any questions. i started a thread a long while ago about my quest to make subsonic 300blk

300Blk subsonic

Appreciate the link, I've got some reading to do!

 

[Ura-Ki]

you want a supersonic or subsonic load? i have both. i can text it to you

Yes please!

 

[ferret427]

I really haven't done any load development for my 300blk. I cherry picked a load online and it has worked well so far. I have only shot supersonic, as I do not have a can yet.
I have a 9.5" SBR with a Black Hole Weaponry polygonal barrel ( don't remember the twist rate, 1:8 or 9 I think) I am using an Eotech 512 optic.
I have been running LC.223 brass converted to 300blk with 17.5gr H110 and Hornady 125gr SST projectiles (a lot of effort to convert the brass, but it's a hobby right?).
Shooting with a front rest and rear bag, I am getting 1-1.5 moa at 100yds.
I have recently switched to Speer TNT projectiles. The groups have opened up to about 2moa, but the bullets are a bit less expensive.
Given that my optic has a 1moa dot and that I have not done any load development, 1-2 moa is about as good as I can expect at the bench.
I went with H110 because I saw recipes for both supers and subs using the same powder. I have no idea if it is optimal for either application; I picked it to keep things in the reloading room simple.
At any rate, I have had no function issues with this load with about 500 rounds shot.
I would also love to hear from people who have developed loads for supper and subsonic shooting with this cartridge!

 

[DizzyJ]

im a big fan of Accurate 1680 powder....its what AAC recommends for supers and subs....you know..AAC, they invented the round...

This.

 

[11Charlie]

im a big fan of Accurate 1680 powder....its what AAC recommends for supers and subs....you know..AAC, they invented the round...

Sweet I'll have to look and see if I have any.

 

[ferret427]

Do you have a link? I would like to see what they say. My impression is that most commercial ammo makers do not post their loads. I need all the help I can get.

 

[11Charlie]

Hey @11Charlie there's a Bushmaster in .300 Blackout already built, for sale here
WTS/WTT OR - NIB BUSHMASTER MINAMALIST IN .300 BLACKOUT PRICE REDUCED

I have the upper and all the parts I just need to mill out the 80% lower and build it.

 

[Ura-Ki]

Im looking to use 62, 72, 77 and 80 gr bullets!
Havnt picked my parts for the .300 yet, likely a twin to my existing 10.5 inch upper!

 

[Mygrainman]

It's way cheaper to make your own 300bo brass..
This is the stuff you MUST have...
Do not use LEE dies for 300 bo case forming...


The 300 blackout reloading/case conversion essentials:

Brass Splitting 300 Blackout Case Cutting Trimming Jig

2 in. Mini Bench Top Cut-Off Saw

https://www.amazon.com/L-Wilson-CG-3ACC-Blackout/dp/B00EVNUXH2

RCBS .300 AAC Blackout Sb T/C Set 22407 27% Off

 

[v0lcom13sn0w]

Do you have a link? I would like to see what they say. My impression is that most commercial ammo makers do not post their loads. I need all the help I can get.

lower left of page.

https://www.advanced-armament.com/assets/images/pdf/manuals/300BLK-AACUpper-MiniBro.pdf

 

[edzz]

Im looking to use 62, 72, 77 and 80 gr bullets!
Haven't picked my parts for the .300 yet, likely a twin to my existing 10.5 inch upper!

Would suggest not having twins.
A 300 Blackout cartridge can be chambered and fired in a 5.56, not a good thing, as in bad, very, very bad.

The way my AR's are setup I can't mistake my Blackout uppers for my 5.56 uppers. I also use Magpul magazines exclusively for 5.56 and Lancer magazines exclusively for 300 Blackout, they look and feel different, even put a thick red rubber band on the Blackout mags.

 

[ConcernedCitizen]

Thanks guys. I would like to find a round that does it all. Like @erslll mentioned cost really isn't the issue and it would be nice to have one that all my AR's like no matter what I am doing with it.

Paper, coyote or the two legged threat. I don't ususally take my AR to the range when I go but would say that If I do I don't shoot more than two or three mags. I am sure that even with more expensive bullets its cheaper loading it than buying mid grade or good ammo.

If it's just paper punching, it's hard to beat the Hornady 55gr FMJ-BT. It's generally considered one of the most accurate of the 55gr FMJ bullets, and can often be found for less than $0.08 each when bought in bulk. I think my last purchase was $0.065 each when I caught them on sale.

For an all-purpose projectile, look into the Hornady 55gr SP. Same price as the FMJ, and supposedly a bit more accurate. The SP is good for varmints and self defence, but is still cheap enough to plink with. Another bonus of using a soft point is that it will still expand at lower velocities, making it perfect for SBRs or AR pistols.

If accuracy is the goal, it's hard to beat the Sierra 69gr & 77gr MatchKing.

For .300BLK, 147gr FMJ work well enough for plinking, and you can often find great deals on pulled bullets.

For home defense, the Barnes 110gr TAC-TX is king. For a cheaper alternative, look at the Hornady 110gr V-Max or the Nosler 110gr Varmageddon. Expansion tests still look good at 2,100 fps.

For subs, there are almost too many options to choose from. The 208-220gr bullets seem to be the most popular, but I picked up a bunch of 190gr Hornady Custom Competition when they were on sale. I haven't had a chance to test them yet, but I've read good things online. The sale price was just too good to pass up...

There are plenty of options to choose from, but I definitely recommend giving the Hornady 55gr FMJ-BT & SP a try.

 

[Twodogs]

Did a lot of testing with subsonic 300 blk loads in a 16" bolt action and an 8" Ar-15 lil-gun was the winner for me. 1680 was to loud and gassy, the faster the twist the better, I see sig is running a 1-6" in their .300 blk .