Share your 300 Blackout Loads here>

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ss_74
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Re: Share your 300 Blackout Loads here>

Post by ss_74 »

Gentlemen greetings,

Looked through lots & lots of great data for the 300 aac, however I noticed very few
posts that listed any groups for the noted load data.

To me most important information.

To make an extremely long story short, best load in both toys (16" & 9" supressed) 1.5"
for the 16"@100 yrds, .75"@50yrds for the 9". Loading bullets at minimum C.O.L. or at
max (leaving 0.005 before touching the throat) had very little effect on accuacy for either.

Same as above for numerous loads from min through max (@0.2 increments).

All of the loads I've tried all funtioned perfectly in both weapons, using both 20/30 round
pmags.

I'm using virgin L/C brass, Hodgdon Lil'Gun, WSR primers, bullets are the excellent Barnes
TTSX 110gr, and the Hornady 130 SS PB (old ones no longer made by Hornady).

Once again, lots of great information on this website, Kudo al!

I guess the next logical step (for me anyway) is to try the H110.

Thoughts?

Best wishes


Art
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Maryland_Shooter
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Re: Share your 300 Blackout Loads here>

Post by Maryland_Shooter »

ss_74 wrote:Gentlemen greetings,

Looked through lots & lots of great data for the 300 aac, however I noticed very few
posts that listed any groups for the noted load data.

To me most important information.

To make an extremely long story short, best load in both toys (16" & 9" supressed) 1.5"
for the 16"@100 yrds, .75"@50yrds for the 9". Loading bullets at minimum C.O.L. or at
max (leaving 0.005 before touching the throat) had very little effect on accuacy for either.

Same as above for numerous loads from min through max (@0.2 increments).

All of the loads I've tried all funtioned perfectly in both weapons, using both 20/30 round
pmags.

I'm using virgin L/C brass, Hodgdon Lil'Gun, WSR primers, bullets are the excellent Barnes
TTSX 110gr, and the Hornady 130 SS PB (old ones no longer made by Hornady).

Once again, lots of great information on this website, Kudo al!

I guess the next logical step (for me anyway) is to try the H110.

Thoughts?

Best wishes


Art
Looks like you have it wrapped up pretty well. I typically settle down ES/SD and velocity before I move to long range accuracy testing, but what you have is plenty good for any work I'll be doing.
When I go to bed a law abiding citizen and wake a felon, by the stroke of the legislative pen, tyranny has arrived.

Post complete and accurate info when inquiring about loads, or be ignored.
Dbuffington
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Re: Share your 300 Blackout Loads here>

Post by Dbuffington »

Hi Folks!

First, many, many thanks to all the good folks who have posted their 300 Blackout loads and experiences here. You’ve taught me a lot!

Now ...

I’ve spent waaaay too much of my vacation time doing subsonic load development for 300 Blackout, but finally, I think I’m close to a good load …

Load number: 31
Caliber: 300 AAC Blackout
Brass: Hornady (used, resized)
Primer: CCI 450 (Magnum Small Rifle)
Powder: VihtaVuori N110 8.4 grains
Bullet: Hornady AMAX 208 grain
Cartridge overall length: 2.23 inches
Platform: AR-pattern, CMMG upper, 16 inch barrel, 1:8 twist

Accuracy? The attached target shows five shots at 50 yards in light wind conditions. The group measures 0.36 inches, and I’m sure under calm wind conditions -- with a better marksman -- it would be smaller.

Image

Function? No serious problems. The rounds feed and cycle properly with the YHM Phantom suppressor on. (I haven’t tried them with the suppressor off.) However, the bolt does not lock back after the last round. (Would a different recoil spring address that issue?)

Sound? Quiet, silly quiet. Every round I’ve tried has stayed subsonic, but please note that I’ve been shooting in summer temps (80-90 degrees), and we won’t know for sure until we get some colder weather. The N110 powder seems to have an exceptionally low blast, and as a bonus, it produces very little smoke.

However, I got similar accuracy with a 8.0 grain load, and so, I think it will be possible to put together an all-weather, subsonic cartridge.

Problems? The Hornady brass is difficult to prime, and I’m going to try Remington brass to see if the results are similar. The N110 powder -- a stick type powder -- is a pain to meter.

Now for some speculation …

I _think_ the critical factor here is the cartridge overall length (COL), and the shape of the AMAX bullet allows a relatively long COL while still allowing proper feeding. (By comparison, I had to set Sierra Match Kings back a considerable distance to get proper feeding.)

Enjoy!
Dave
ss_74
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Re: Share your 300 Blackout Loads here>

Post by ss_74 »

Gentlemen greetings,

Finally got a decent group using the Hodgdon 110 in lieu of the Lil' gun I had been
testing earlier on.

Temperature was 82 but the humidity was murder (92%) it is, however summertime
and the 'dog days' are still on the horizon.

Disclaimer: This load is safe only in my rifle.

case: virgin L/C
primer: WSR
powder/load: Hodgdon 110 / 19.2 grains
bullet: Hornady 130grain SS/PB
c.o.l.: 2.045"
group: 4 shots went into 0.60" the fifth was a flier and opened the group up
to 1"moa@100 yards.

My starting point for the H110 was 18.0 grains working up in 0.2 increments.

The estimated velocity on paper indicates approximately 2180 fps +/-.

Time to break out the (ancient) Oehler 35 to confirm the velocity/s.d.

The loads tested for the Barnes 110gr TTSX bullets were dismal; 2.25" was the best.

Back to the drawing board for those puppies.

Best wishes,


Art
Dbuffington
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Re: Share your 300 Blackout Loads here>

Post by Dbuffington »

Here’s an update with some chronograph data...

I made a minor change to my earlier successful load, replacing the Hornady brass with Remington brass:

Load number: 32
Caliber: 300 AAC Blackout
Brass: Remington (used, resized)
Primer: CCI 450 (Magnum Small Rifle)
Powder: VihtaVuori N110 8.4 grains
Bullet: Hornady AMAX 208 grain
Cartridge overall length: 2.23 inches
Platform: AR-pattern, CMMG upper, 16 inch barrel, 1:8 twist

Like the earlier load, this gave excellent accuracy. Here are 10 shots at 50 yards. (The inner ring is two inches in diameter.) I was shooting over the chronograph, not trying for maximum accuracy, and I’m sure a tighter group is possible:

Image

The numbers are:
995.9
1003
1005
1001
1006
1000
1002
983.5
994.9
998.0

Average = 999.1
Extreme Spread = 22.56
Standard Deviation = 6.7

These numbers are better than I received with the Hornady brass. Why? The Hornady cases were very difficult to prime. (The pockets are very tight.) And I think I may have had some irregularity in the position of the primer in the pocket. Conversely, the Remington cases were easy to prime. That _could_ explain the difference.

Enjoy!
Dave
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JohnInNH
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Re: Share your 300 Blackout Loads here>

Post by JohnInNH »

Dave did it cycle?
Long distance, the next best thing to being there!
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darr3239
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Re: Share your 300 Blackout Loads here>

Post by darr3239 »

I'm liking the posts with lots of info., but many times differenct items of interest are left out, as mentioned by others.

I posted this on another thread, and it gets to what is important to me:

"My main thing personally is accuracty, both sub and supersonic. The load must yield total functionality of the weapon, ie. locking back on empty mag. and no other malfunctions. If it's accurate but........... can it. Or it functions great but accuracy isn't good.....same thing.

When I am done playing around with different loads, I think the ultimate goal is, can I trust my life on the load, and the gun I'm using it in? This actually translates to hunting, since no one wants to miss the shot of a life time, due to a malfunction.
"We, the people are the rightful masters of both Congress and the courts, not to overthrow the Constitution, but to overthrow men who pervert the Constitution." Abraham Lincoln
Dbuffington
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Re: Share your 300 Blackout Loads here>

Post by Dbuffington »

JohnInNH wrote:Dave did it cycle?
Short answer: Yes.

Long answer: It was cycling but not locking back on an empty magazine. I thought it was a problem with the load, but just today, I discovered it wasn't locking back at all, even manually.

Here, the Magpul BAD I had installed (and have installed on several AR lowers) rubs every so slightly on the Plum Crazy polymer lower :oops:

So, I removed the BAD, and everything appears to function properly now, BUT I haven't taken it to the range yet for a full test just to be 100% sure.

Stay tuned.

Thanks!
Dave
MajorTom
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Re: Share your 300 Blackout Loads here>

Post by MajorTom »

Function tested my new loads today. Temp was 65F, humidity was 60%, elevation 300ft. Brass was once fired Hornady/Remington. All loads used Remington 7 1/2 primers.
Unknown velocity/accuracy on all loads. Magazines used were 30rnd PMAGS.
Gun used was a AR franken build using a 1/8 16in Noveske/carbine gas barrel, ST NiB bcg, and carbine weight buffer. No suppressor was used.

I first tried Hornady 225gr HPBT using 9.9gr of h110 coal of 2.230. Didn't cycle well(ejected fine but occasionally short stroked), should be fine with a suppressor. I then tried 9.5gr with same specs and they cycled very poorly, often jamming. I then used A1680, same bullet, OAL of 2.120 using 11.2gr and then 10.9gr. Both loads cycled well. All four loads were subsonic from what I could tell.
Hornady 150gr FMJBT using 16.5gr of h110 and a OAL of 2.100 cycled well. I think this will be my plinking load.
Sierra 110gr HP using 19.5 of h110 and a OAL of 1.983 cycled beautifully.
Hornady 110gr VMAX using 19gr of h110 and a OAL of 2.000 cycled well.

I didn't notice any over pressure signs at all, and all my brass had dented mouths. This worked in my rifle, use at your own risk!

I've tried Speer 130gr hp with a OAL of 1.950, but they kept getting stuck on the feed ramps. Has anyone gotten them to feed well?
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pomofo
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Re: Share your 300 Blackout Loads here>

Post by pomofo »

Magnetospeed chronograph results.

All loads fired through a 16" 300 Fireball upper with carbine gas.

125 Speer TNT at 2.050" COAL with 21.2 grains of Accurate 1680.

Predicted performance from Quickload is 2208fps.

1. 2016
2. 2044
3. 2035
4. 2008
5. 2034
6. 2021
7. 1994
8. 2021
9. 2010
10. 1962

AVG 2014
ES 82
SD 23


220 Hornady RN at 2.000" COAL with 10.4 grains Accurate 1680. Last round jammed, but this load normally locks back the bolt after the last shot.

Predicted performance from Quickload is 1146fps.

1. 833
2. 936
3. 914
4. 916
5. 954
6. 922
7. 933
8. 930
9. 927
10. Jammed and shoved bullet back into case.

AVG 918
ES 121
SD 34


225 Hornady BTHP at 2.240" COAL with 9.6 grains Accurate 1680. Did not lock back on last shot.

Predicted performance from Quickload is 1090fps.

1. 818
2. 840
3. 832
4. 809
5. 814
6. 846
7. 825
8. 780
9. 789
10. 792

AVG 814
ES 66
SD 22
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