Test Specifications/Components
Firearm Used: Universal Receiver
Barrel Length: 16″
Twist: 1-8’’
Case: Hornady
Trim-to Length: 1.363″
Primer: Winchester WSR
Remarks:
The 300 AAC Blackout (300 BLK, or 7.62x35mm) was created by Advanced Armament Corp. and Remington in order to provide the military with a way to shoot .30 caliber bullets from the M4 platform with only a barrel change. It has since become popular for a wide range of uses including hunting and home defense.
The cartridge shares case-head dimensions and body taper with the .223 Remington. Not only does this allow for compatibility with existing magazines and bolts, but it allows reloaders to form their own brass from cut-down 5.56mm or .223 cases – ensuring brass supply even in the event of a shortage of factory brass.
The 300 AAC Blackout is a similar concept to previous wildcats, such as the 30-221 and 300 Fireball, as well as the proprietary 300 Whisper®, except that 300 BLK was the first to be a SAAMI approved cartridge and any company is free to make firearms or ammunition.
300 AAC Blackout is also finding use with hunters, who may not have been able to legally hunt with .223 in their state, and who prefer .30 caliber bullets for medium-sized game. It provides similar effectiveness to the 7.62×39 or the slightly more powerful 30-30 cartridges except works in the more up-to-date AR15 platform. Effective range for hunting is about 100-150 yards.
Click here to download Sierra Bullet’s 300 AAC Blackout Load Data for the 5th Edition Manual
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
Sierra Bullets 
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If you guys had bothered to ask people what powder they would like to see lil gun would definitely be on that list. I would say 10 times more people use lil gun than R7 for subsonic loads.
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Amen to Li’l Gun
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Since my post back in Jan 2019, I have switched and li’l Gun cut the groups in half.Sub sonic. 1 MOA. Cycles better than anything. I have a 16″ bbl. Runs with or without a suppressor.
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Why not give JD Jones credit for the development of the 300 Whisper, which AAC tweaked into the 300 AAC Blackout by increasing the length of the chamber throat 0.015″ and SAAMI-ed it.
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Screw JD Jones who sat on his product and refused to share his creation after earning millions. He is a greedy old has been who would have let this cartridge perish. He deserves NOTHING and would tax the IRS if he could do it.
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Pingback: NEW: Sierra Bullets .300 AAC Blackout Reloading Data - AK Arms
Pingback: NEW: Sierra Bullets .300 AAC Blackout Reloading Data | Firearms Life
will these loads cycle an AR?
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They should. – Duane Siercks, Ballistic Technician
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220 g round nose / 9.9 g H110 cycles 8.5″ and 16″ barrels no issues.
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In my 16.5″, X95 Sierra 220 grain RN with 11.2 grains of H110 WILL NOT cycle. In my Palmetto State Armory 7.5″ upper the load functions perfectly ! What could be the problem with the load in the 16.5″ ?
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A carbine length gas system (one comment mentioned 16.5 inch gun would not cycle the action) will not work with subsonic loads in 300 blackout. There may be rate exceptions but your in for a lot of frustration if you go that route. You MUST have a pistol length gas system. My TSAR 11.5″ upper is flawless so far.
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180 grain rainier wedges cycled with 11ish grains of IMR4198 out of my PSA 10.5in suppressed with Syrac Ordinance adjustable gas block.
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How do you guys get different data for Win 296 and H110? Hodgdon reports that they are the identical powder under different labels.???
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My exact same question.
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While the powder formulas are identical, the chrono testing is likely from different production lots. You may have a great load that is pushing max and loading from an 8lb keg, and a few years later you buy another keg. Smart and safe loader will back off the load and work it back up simply due to powder age and lot variation.
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You all show older data in the 300 using lil gun for a load workup option. Is that obsolete now, or not recommended. Using 125 gr prohunter
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I really appreciate the updated data, I was working on subsonic loads and Sierra did the work for me. That’s a lot of work already done that I only need to tweak for my rifle, however when I chrono these loads Sierra is pretty much dead on!
Now for preparations for 2018 Bear season…
Thanks
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The data is all wrong anyway. Example 220gr subsonic data there for h4198 and reloader 7… two things…first not in anyway subsonic…they are high velocity. Second stupidly and even dangerously compressed loads…
If you folks want really figures use quick load…this data and noslers data is bogus.
Want a subsonic load using reloader 7 or h4198? Oal 2.260 8.7 grains
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Quick Load program is, buy their own admission should NEVER be used over ANY published data. I have used this program for years and tke it with a very large grain of salt!
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So how does everyone find the stability of the heavier projectiles with the 1-8″ twist rate? I have seen a few complaints from people with barrels under 10″, but better stability was found when switching to a 1-7″ twist rate.
I plan to build a bolt action with a 16.5″ barrel and will use projectiles between 180 – 220 gr., so not sure if I should go with the 1-8″ or get a 1-7″ barrel blank made. Any thoughts?
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Have experienced some unstability problems with cans and 1:8 barrels with 220 gr sierras. Ordered 1:7 barrel to another gun, used same loads in exactly same conditions, no issues. 220 sierras were stable to 150 meters with 1:7 twist. Instability with 1:8 caused problems with loger cans, bullet maybe wobbling after rifling. Also slight keyholing and groups growing up. Never seen that with 1:7 rifling twist.
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Offcource in case of subsonic 300 BLK, forgot to mention, sorry.
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12 gr. H 4831, 220 gr RN Fed 205 heavy factory crimp, 1050 fps cycles my 16″ M4. JP silent spring, 1 1/2 MOA . AAC 7.62 Suppressor , Crimp is most important as heavy bullets want to move on recoil in the mag and will cause vertical stringing
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The 300 bulk is an underpowered cartridge-on par with theM1 carbine of WWII- but not as easy to wield. Why not put all pomp aside and manufacture light bullets for this PISTOL? The velocities cited for the BLK are asthmatic. All this suppressor talk does not apply to 98per cent of the public. In a life and death situation-who cares about the noise? I know, how about the virtues of a bow or crossbow?
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7.3 grains of trail boss seems high even for max charge. It is a compressed load and I have read about the dangers of compressing trail boss..
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+1; Yup, TB gets really wonky if you compress it. Just say’n
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I switched to Lil’Gun for 220RN sub groups we t down to under 1 MOA cycles 26″ bbl great. Remember sib sonic loads are only a 100 yd load. 12″ drop at 150 yd. Close range only
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That’s a 16: bbl. 1/8 twist. Carbine length gas tube.
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subsonic 300blk. powder: A1680. Sierra 180Grain match king projo, 12.2 grains of powder. 1020FPS with last round bolt hold open
Firearm: 8.5″ CMMG Barrel, H3 heavy buffer, superlative arms adjustable gas block, 30 Cal Kinetic Suppressor. works like a charm.
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