Share your 300 Blackout Loads here>

[Jburcaw]

That's great. Thanks for the info. My goal is one inch groups. I don't plan to shoot bench with it, but I do like making clean quick kill shots, so accuracy is important to me. I just ordered so nosler 125 bt, so once I develop a load with shooting data, I will post it. I loaded up some vmax 110s, but mentally the huge jump to the lands just bothered me, so I never shot them. I know there are slot of guys using them with good results, I just prefer, from a confidence standpoint when hunting, a larger bullet, less jump, and a bullet designed to hold together. Maybe I am way off the reservation.

[AF275]

I'm have some issues trying to figure out a good overall length for these bullets. I've got 100 Speer TMJ Round Nose 110gr I was going to load just for some plinking.

Here is the on the bullet:
http://www.speer-bullets.com/ballistics ... aspx?id=81

When I was getting 2.00" I could pull the bullet out of the case, but this was before crimping but it raised some concern.

I am using resized LC brass, and the Lee die set and Lee crimp die and the barrel is a 16" AAC, non suppressed for now.

I've seated one bullet in an unprimed case to 1.90" and it felt to have a much firmer seat in the case and as well it fed fine from a PMAG, bolt fully engaged, and ejected fine. But I wanted to get some thoughts/opinions from folks with more familiarity with this round. All my loading experience has just been .223 up til now.

This is my first time using a round nose bullet vs a more common formation so wasn't sure if that was something to take into consideration when defining a good overall length.

Appreciate the help!

[mechanicus]

ar15
barrel: Wilson Combat 16"
alt 600, temp 93F, RH 82%, wind 0

L-R

Hornady 110gr sp (#3010), Fed 205 primer, Win WCC case, COAL 2.00,
20.6 gr Hodgdon H110
vels: 2322, 2314, 2331

Speer 130gr flat sp (#2007), Fed 205 primer, Win WCC case, COAL=cannelure
18.0 gr Hodgdon H110
vels: 1981, 2007, 1993
note: will not feed reliably - flat nose hangs on feed ramps -
was a good deer bullet for me in 30-30 but the flatnose experiment did not work...

Sierra 165gr SGK (#2145), Fed 205 primer, Win WCC case, COAL=2.160
15.8 gr Hodgdon H110
vels: 1729, 1752, 1733

Sierra 168gr SMK (#2200), Fed 205 primer, SSK Whisper case, COAL=2.160
15.7 gr Hodgdon H110
vels: 1700, 1724, 1718

[DEVIL DOC]

tagged

[HK91]

Hello,

HK91 here, mostly a lurker, got the 300 Blackout bug a few months back, finally got the LEE dies and a chance to try some loads.

16" AR-Performance Barrel, used one of my lowers with an A2 stock.
No suppressor yet
Brass formed from LC mil 5.56 by a guy on Quarterbore
Wolf .223 Small Rifle Primer

190 gr Sierra BTHP moly-coated (I got 2k of these bullets as blems from Lock Stock and Barrel several years ago, pre-molyed for $65 per 1K)

Accurate Arms Data Powder 2200 (I got 32 pounds of this in the mid-90s and have 16 pounds left)

Shot on two different days, first batch the temp was about 90, the second batch was about 80, no significant wind, altitude 1100 feet. Groups ran from 3/8" to 1" at 50 yards. Only had one set of 5 rounds for each of the loads listed. The loads without SD's I was only able to capture 2 or 3 of the velocities out of 5. I have an old Oehler Model 33 chronograph with Sky Screen II, instrumental velocities at 12 feet. Before chronographing the loads I chronographed my CZ452 Special 22 LR and velocities were very similar to previously chronographed ammo (I usually do this to make sure I got things set up correctly).

CARTRIDGE DATE Pwdr Wt POWDER OAL Vel SD
300 AAC 8/12/2011 12.50 AA2200 2.225 1020 72
300 AAC 8/12/2011 13.70 AA2200 2.225 1070
300 AAC 8/12/2011 14.40 AA2200 2.225 1173
300 AAC 8/12/2011 15.30 AA2200 2.225 1270 35
300 AAC 8/12/2011 16.20 AA2200 2.225 1336 16
300 AAC 8/12/2011 17.10 AA2200 2.225 1441
300 AAC 8/12/2011 17.40 AA2200 2.225 1405 14
300 AAC 8/12/2011 18.10 AA2200 2.225 1460
300 AAC 8/12/2011 18.50 AA2200 2.225 1535

300 AAC 8/20/2011 13.60 AA2200 2.145 1019 17
300 AAC 8/20/2011 18.00 AA2200 2.145 1521 10
300 AAC 8/20/2011 18.50 AA2200 2.145 1584 9
300 AAC 8/20/2011 19.00 AA2200 2.145 1607 12
300 AAC 8/20/2011 19.50 AA2200 2.145 1677 18 *** I don't think I could get any more powder into the cases.

The first batch the OAL was too long to function with the C-Products 20 round SS mags I have. The second batch of loads functioned fine except the subsonic's which would not cycle the action reliably or hold the bolt back on the last shot. No signs of excessive pressure on any of the loads, primers still well rounded at 19.5 grains.

Shoot Straight,

HK91

[BretJ]

Been lurking here a while trying to get my ducks in a row. After looking at a lot of loads, am I wrong in the assumption that H110 seems to be best all around powder for this cartridge? Want to buy propellant that can be loaded super and sub and I see it used for both alot. BTW, I have a few pounds of Universal and Long-Shot. Use them for 45LC but was wondering about the possibility of using these as well in 300AAC.

[stmcelroy]

Been lurking here a while trying to get my ducks in a row. After looking at a lot of loads, am I wrong in the assumption that H110 seems to be best all around powder for this cartridge? Want to buy propellant that can be loaded super and sub and I see it used for both alot. BTW, I have a few pounds of Universal and Long-Shot. Use them for 45LC but was wondering about the possibility of using these as well in 300AAC.

You need two different powders for supersonic(H110 or equivalent) and subsonic(A1680 or equivalent).

Listed Below is the suggested loading info released by AAC.
http://www.300aacblackout.com/

HANDLOADING INFORMATION

If you load your own ammo, pay special attention to all of the normal safety practices.
Recommended powder for most supersonic loads is Hodgdon H110.

For subsonic, there are special requirements and nearly all published loads are non-optimal for the 300 BLK upper.
Many existing loads were developed for Thompson Center® single-shot pistols,
or for ARs by people not aware of the magazine limitations.
These loads pay no attention to automatic rifle function and should not be used.
Look for a load which results in a cyclic rate of 700 rpm or more.
A1680 is recommended because its bulk density matches the case capacity and it will generate enough gas pressure to cycle the weapon.


Suggested subsonic load:

• R-P 300 AAC BLACKOUT brass
• Remington 7.5 primers
• 11.2 grains of A1680 powder
• Case length is 1.368 +0.000 -0.020
• Sierra 220 MK loaded to 2.089 OAL (this length is optimal for reliable feeding from USGI magazines)
• Chamber pressure 21,100 psi.

Existing AR magazines have a rib which normally contacts the 5.56mm case-neck.
With 300 BLK ammo, the contact is on the bullet.
Because the bullet is a larger diameter, the rib will push the cartridges out of alignment,
and can lead to binding potentially resulting in Failures to Feed.
For this reason, it is important to load ammunition so that the contact point with the magazine rib is on the bullet ogive in an area of about 0.250 inch diameter.
Here are some suggested OAL for popular bullets:

• Hornady 110 V-Max, OAL: 2.000
• 110 TSX, 2.015 OAL
• Sierra 155 Palma, 2.150 OAL
• Sierra 220, 2.089 OAL
• Lapua B416 200 grain, 1.960 OAL
• Hornady 150 FMJ-BT 3037, 2.065 OAL
• Nosler Ballistic Tip 125 grain, OAL: 2.085
• Remington AccuTip 125 grain, OAL: 2.085
• Hornady 130 SP #3020, OAL: 2.010
• Sierra H2120 125 ProHunter, OAL: 1.950
• Speer TNT 125 1986, OAL: 2.010

[Mayday671]

Temp: - 61 deg Humidity: - 33% Pressure: - 30.34 Altitude: - 802 ft

Rifle: Bushmaster AR-15 Short Barrel Rifle Barrel: Delta Company 10.5"

Bullet: 208gr A-Max
Powder: Reloader 7
Charge: 11.1 grains
O.A.L: 2.15

Average: 1047 fps

Rd 1: 1056 Rifle will not cycle and bolt will not lock to the rear.
Rd 2: 1057
Rd 3: 1051
Rd 4: 1061
Rd 5: 1088
Rd 6: 1055
Rd 7: 1056
Rd 8: 1009
Rd 9: 1037
Rd 10: 1052

Looks like the 208's may not work for me. 220 SMK and 240 SMK works well and Im going to attempt the 225 gr Hornady HPBT

[Mayday671]

Temp: - 61 deg Humidity: - 33% Pressure: - 30.34 Altitude: - 802 ft

Rifle: Bushmaster AR-15 Short Barrel Rifle Barrel: Delta Company 10.5"

Bullet: 208gr A-Max
Powder: Reloader 7
Charge: 11.1 grains
O.A.L: 2.15

Average: 1047 fps

Rd 1: 1056 Rifle will not cycle and bolt will not lock to the rear.
Rd 2: 1057
Rd 3: 1051
Rd 4: 1061
Rd 5: 1088
Rd 6: 1055
Rd 7: 1056
Rd 8: 1009
Rd 9: 1037
Rd 10: 1052

Looks like the 208's may not work for me. 220 SMK and 240 SMK works well and Im going to attempt the 225 gr Hornady HPBT

[Mayday671]

Temp: - 61 deg Humidity: - 33% Pressure: - 30.34 Altitude: - 802 ft

Rifle: Bushmaster AR-15 Short Barrel Rifle Barrel: Delta Company 10.5"

Bullet: 240gr Sierra Matchking
Powder: Reloader 7
Charge: 11.1 grains
O.A.L: 2.255

Average: 996 fps

Rd 1: 1018 Rifle cycles flawlessly and bolt locks to the rear.
Rd 2: 1010
Rd 3: 1011
Rd 4: 942
Rd 5: 1001
Rd 6: 982
Rd 7: 993
Rd 8: 1009