I Wil bet your velocity is well below 800 fps.

Did you start high and work down?

You are risking a SEE.

I am getting into loading for 300 blk. I have a few different powders and bullets and am trying to get some guidance before I order. The powders I can order that look like they will work are Reloader 7 or H4198 and the bullets I have available are SMK 175, 208 OTM, or 220 SMK. Any guidance would be appreciated.

ETA: I could get the nosler 190 hpbt also if those would work well.

Not sure if correct place to ask but...

Who sells the best 300blk brass? Have read a few horror stories about converted brass that was out of spec.

I would do it myself but I doubt the people in the apt next door would be happy about a chop saw running/cutting.

Be aware that even if you buy "ready to load" brass (in ANY caliber), you should verify that the cases are actually properly sized and trimmed before you start loading them.  For example, if the 300 Blackout brass you buy was converted and trimmed in one pass on a Dillon 1050, there's a chance that the case neck wasn't expanded properly because of how the Dillon trim/size system works.  

You might want to invest in a cartridge headspace gauge if you're going to be buying your 300 Blackout brass.  Using the cartridge headspace gauge, you'll be able to tell quickly whether a batch of purchased brass really is properly converted and trimmed.

Tagged!!

I searched and went back a few threads looking for this info.
Has anyone shot the Blackout bullets in 220 grain fmj's ? If so could post the oal and what powder you settled on ?
Thanks Ed

So I loaded a few with 12 grains of RL7 and sent them down range in my Rem700 . I need a modified case to measure the lands but at 2.26 I bet I'm a ways off.

do any of the heavy OTM subsonic bullets have good terminal ballistics? like reliable yaw?

Short answer, no.

If shooting with a 1 in 10 twist, maybe.  It depends on your barrel.  I have a 1 in 10 twist that stabilizes the heavier bullets, and they tumble well on impact.  most report issues with stabilizing and accuracy with a 1 in 10.

So I FINALLY got myself on some suitable powder.

My FIL picked up two pounds of IMR 4227 today. My wife will pick it up next week.  Ordering my vice block tomorrow to finish the build I got the last part for last week.

My two on hand bullets are Speer Hot Core 150's and Hornady rn 150's.

Hodgdon's data that I have shows 16.5 to 17.8?  

Anyone running into problems with a similar combination?

10.5" pistol build.

Posted Via AR15.Com Mobile

I found some time to shoot my 700 Rem blackout with the Blackout brand 220 grain bullets . My book of AR15 loads suggested Reloader 7 at 12 grains for an accuracy load . I shot a few to check for keyholing before trying my saker suppressor. At about fifty yards it put them right in there the big hole is five shots and the sound is perfect. Over the chrono they shot at  940 fps.
How do I proceed with this load ? Do you guys try to get closer to 1000 fps ? On a bolt gun do you mess with seating length to get the groups tighter ? I had a whisper years ago and only shot the load data the previous owner worked up.
Thanks

I'd check the group size at a measured distance (try 100 yards) and see if it opens up appreciably both with and without the suppressor.  From that 50 yard pattern, you're doing quite well with the load, but if it opens up at longer ranges, then you should start playing with seating depth.

Just got my stamp back and built this rifle. Still waiting on suppressor stamp but would like to build up a subsonic load in the mean time. I have never loaded for the 300blk before but, I am not new to reloading. Bought 1300 300blk/LC brass and then processed it again myself to avoid any QC issues.

Power: AA1680
Projectile: 190gr Nosler Custom Comps
Primer: CCI #41
Altitude: 5280ft
Target FPS: 1050

Barrel: Ballistic Advantage CMV/QPQ 1/7 Twist 8"
Gas: Pistol length, NON adjustable block
Buffer: Standard rate CS spring + Spikes T2 buffer

I am pretty much looking for anyone who has loaded this same load before. I will be doing ladder tests but I need a good starting point. I have searched and peoples loads range from 11.2-13.5. I do NOT have a chrony so I will be playing this by ear (literally).

Any direct advise would be great!

The best advice.  Get a chronograph.

Seriously, I tried the by ear thing.  Had a good accurate load.  Took 2 deer with it.  6 point buck and a small doe.  Got my chronograph repaired.  Ran load over chronograph and my velocity was 850fps. Well below the 1000fps I was shooting for.

"By ear" testing of whether or not a round is supersonic is a poor choice.  Actual speed of sound varies as a function of temperature, humidity and atmospheric pressure air density.  If you want to make sure a load STAYS subsonic, load it to be in the 950-1050 fps range.  

Aiming for a velocity that's BELOW the LOWEST speed of sound you could encounter is the ONLY way to guarantee that your load will stay subsonic.  The "book answer" for speed of sound at sea level (standardized air pressure) is 1,116.43+ fps, in "dry" air at ~15ºC.  Higher temperatures give lower higher sound velocity, while lower temperatures give higher lower humidities, and higher air pressures give higher velocities.  Humidity affects air density, but barometric pressure does not.  Adjusting for 0% to 100% humidity, atmospheric pressure from below sea level to above 8,000 ft elevation, and normally experienced temperatures only produces a 1-3 m/s change in the speed of sound, so staying "comfortably below" 1,100 fps should do the trick.

On the other hand, different powders can produce different velocities in different environmental conditions.  There are a lot of powders that are "just a little hotter" when the weather is hot.  While the speed of sound won't change much in hot weather, your actual velocity could change, and it could change substantially if you're close to sonic velocities.  There are not many powders that are suitable for subs in 300 Blackout that have been optimized for minimal performance changes in different temperatures, so getting your load right for your purposes means testing in both hot and "not so hot" conditions; remember, the speed of sound goes UP  in cooler air while temperature-sensitive powders tend to be slower in the cold......that was actually irrelevant.

But remember, there is no way to 'eyeball' velocity.  Get or borrow a chronograph to tune your "gotta be subsonic" loads.

Edited to fix a tag and replace some wording for clarity, and un-mangle my screw ups...

Sorry, but the speed of sound is proportional to the temperature of the air, thus as the temperature increases, so does the speed of sound.

My bad.  You are correct.  I should have put in more details to make that point, and I transposed examples in a couple of places because I didn't include those details and confused myself.

If we maintain the same atmospheric density, the velocity of sound varies in direct proportion to the temperature.  Hot air is less dense and cold air is more dense, so air temperature changes affect the local atmospheric density, regardless of "air pressure".  The lower the density of the air, the higher the speed of sound, because it takes less energy to displace the molecules.  (That's the transposition - I was watching air density versus temperature and stated the relationship backward.)  In my earlier post, I used the term "air pressure," but barometric pressure is not the same thing as "air density."  Dense air may be at a higher barometric pressure, OR it may have more moisture, or both.

In practical application, you need to attend to the extremes of temperature to get the parameters needed for the "absolute maximum MV" you want to load to.  So a HOT day at a higher elevation will give you the highest practical speed of sound, while a COLD day at sea level will give you the lowest practical speed of sound.  Elevation is ONLY important because it implies specific conditions, such as the potential for atmospheric moisture capacity.  Going with 0ºF at sea level, with the numbers I posted above, will give you a truly useful "absolute" speed to stay below.

Very good info HERE about the difference between "air pressure" and air density with regards to their effects on the speed of sound.

i was wondering if anyone has used the 110 hornady soft points on game im looking for a short range 100yard super load for little less money then barnes and ive heard the vmax break up then shoot at close range

I have seen situations where surplus 30-06 M2 AP bullets are loaded into .308 cases to mimic the unavailable M993 7.62 AP Black tip ammo.
https://www.youtube.com/watch?v=nGkmUADl4FA

Has anyone worked up a load for the same bullets in a .300 BO case? I wonder how effective you could get a round to work from a suppressed 9" barrel.
Sorry if I broke any format rules here. But I have looked for days online and found nothing about my query.

I am aware of what the ATF thinks about AP ammo in anything that can also be made into a pistol like the .308 and the 300 black out. I would prefer to set this discussion aside and simply look at the science and feasibility of my query. US Special Forces use the 300 BO suppresses for clandestine missions dont they? I assume they must have spare mags of supersonic ball AND AP 300 BO ammo available if they need to switch to that at some point in their mission. Can their armorers produce (hand load) AP rounds for select missions? Who knows. It may be top secret that some outfit like Lake City Army Ammunition Plant already produces a 300 BO AP round exclusively for the military DEVGRU.

I need some assistance on starting a subsonic load using 170 grain Lehigh defense CF bullets with IMR 4227.  Any suggestions are greatly appreciated.

per Lehigh Defense

Lehigh defense 170gr sub load data

they do no list IMR 4227 for the 170 but they do for the 174

Lehigh defense 174gr Sub load data

Ok I now see the issue, I have been looking on my phone and the form was blank, but just checked on my computer and see it listed now.

Do you think the 174 vs 170 makes a difference in the powder charge? Should I reduce by a grain or two?

no With subsonic you start high and work down  If I was doing it, I would start with 10gr  and work down till I was around 1000fps.  I try to keep all my subs at 1000fps.

Well I had a chance to shoot a few 170gr Lehigh Defense CF rounds.

Troy PAR - 16" Barrel with 7.62 Specwar

170gr Lehigh Defense CF rounds
8.6grs of 4227
Tula Small Rifle Primer
LC converted brass

5 shots average - 1000fps.

How did they function and what mag did you use?

Shot my first loads of 300 blackout today

brass was trimmed to 1.360"
COAL was to Hornady 9th specs..
2.215 for the 30501 168 gr HPBT
2.220 for the 3031   150 gr SP




These were fired from a AR pistol w 10.5" KAC barrel / pistol gas / std mill spec carbine buffer,spring (some with / without) a Griffin Armament Recce 7 Suppressor

All loads functioned / locked bolt back etc.

All were accurate at 30 yds

09-04-2015 09:10:50 AM
Description: Hornady 0.308 300 blkout 14.5gr AA 5744
Notes 1: Hornady 0.308 BTHP Natl M 30501 168 1.215
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 0.450
Bullet Weight (gr): 168.000
Temp: 55 °F
BP: 29.86 inHG
Shots
#     FPS\FT-LBS PF
1     1299\630\218
Average: 0.00
StdDev: 0.00
Min: 1299
Max: 1299
Spread: 0
True MV: 0.00
Shots/sec: 0.00
Group Size (IN): 0.00

09-04-2015 09:15:49 AM
Description: Hornady 0.308 300 blkout 15.9 gr AA 5744
Notes 1: Hornady 0.308 BTHP Natl M 30501 168 1.215
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 0.450
Bullet Weight (gr): 168.000
Temp: 55 °F
BP: 29.86 inHG
Shots
#     FPS\FT-LBS PF
1     1532\876\257
Average: 0.00
StdDev: 0.00
Min: 1532
Max: 1532
Spread: 0
True MV: 0.00
Shots/sec: 0.00
Group Size (IN): 0.00

09-04-2015 09:20:01 AM
Description: Hornady 0.308 300 blkout 11.8 IMR 4227 suppresed
Notes 1: Hornady 0.308 BTHP Natl M 30501 168 1.215
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 0.450
Bullet Weight (gr): 168.000
Temp: N/A
BP: N/A
Shots
#     FPS\FT-LBS PF
3     1265\597\213
2     1257\590\211
1     1195\533\201
Average: 1239.00
StdDev: 38.31
Min: 1195
Max: 1265
Spread: 70
True MV: 1239.00
Shots/sec: 0.20
Group Size (IN): 0.00

09-04-2015 09:23:37 AM
Description: Hornady 0.308 300 blkout 13gr 4227 suppresed
Notes 1: Hornady 0.308 BTHP Natl M 30501 168 1.215
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 0.450
Bullet Weight (gr): 168.000
Temp: 55 °F
BP: 29.86 inHG
Shots
#     FPS\FT-LBS PF
3     1418\750\238
2     1422\754\239
1     1395\726\234
Average: 1411.67
StdDev: 14.57
Min: 1395
Max: 1422
Spread: 27
True MV: 1411.67
Shots/sec: 0.30
Group Size (IN): 0.00

09-04-2015 09:26:51 AM
Description: Hornady 0.308 300 blkout 14.2gr 4227 suppresed
Notes 1: Hornady 0.308 BTHP Natl M 30501 168 1.215
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 0.450
Bullet Weight (gr): 168.000
Temp: 55 °F
BP: 29.86 inHG
Shots
#     FPS\FT-LBS PF
3     1552\899\261
2     1539\884\259
1     1533\877\258
Average: 1541.33
StdDev: 9.71
Min: 1533
Max: 1552
Spread: 19
True MV: 1541.33
Shots/sec: 0.21
Group Size (IN): 0.00

09-04-2015 09:40:56 AM
Description: Hornady 0.308 300 blkout 16.3gr 4227 suppresed
Notes 1: Hornady 0.308 SP 3031 150 1.047
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 0.338
Bullet Weight (gr): 150.000
Temp: 55 °F
BP: 29.86 inHG
Shots
#     FPS\FT-LBS PF
3     1697\959\255
2     1702\965\255
1     1692\954\254
Average: 1697.00
StdDev: 5.00
Min: 1692
Max: 1702
Spread: 10
True MV: 1697.00
Shots/sec: 0.04
Group Size (IN): 0.00

09-04-2015 09:38:59 AM
Description: Hornady 0.308 300 blkout 15.2gr 4227 suppresed
Notes 1: Hornady 0.308 SP 3031 150 1.047
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 0.338
Bullet Weight (gr): 150.000
Temp: 55 °F
BP: 29.86 inHG
Shots
#     FPS\FT-LBS PF
3     1600\853\240
2     1586\838\238
1     1547\797\232
Average: 1577.67
StdDev: 27.47
Min: 1547
Max: 1600
Spread: 53
True MV: 1577.67
Shots/sec: 0.25
Group Size (IN): 0.00

09-04-2015 09:34:48 AM
Description: Hornady 0.308 300 blkout 14gr 4227
Notes 1: Hornady 0.308 SP 3031 150 1.047
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 0.338
Bullet Weight (gr): 150.000
Temp: N/A
BP: N/A
Shots
#     FPS\FT-LBS PF
3     1529\779\229
2     1361\617\204 (not sure why this was so slow... maybe i had a bad throw from powder measure? )
1     1521\771\228
Average: 1470.33
StdDev: 94.77
Min: 1361
Max: 1529
Spread: 168
True MV: 1470.33
Shots/sec: 0.03
Group Size (IN): 0.00

Heads up....

Midway has Barnes Blacktip bullets for $21.83/box.

http://www.midwayusa.com/product/614359/barnes-tipped-tac-tx-bullets-300-aac-blackout-300-whisper-308-diameter-110-grain-flat-base-lead-free-box-of-50

10-4

16" barrel (rifle length gas tube)
208 gr Amax bullets
11 grains Accurate 1680

Sighted in at 100yds I am 30 inches low at 200

That normal?

I'm no expert, and I'm sure someone with more inclination to do the ballistics math will be along shortly, but yes. For a subsonic round, that sounds like it's in the ballpark.

According to Hornady's ballistic chart, with a MV of 1020 fps with a 100 yd zero; at 200 yd, the drop is 34.1 in.

Ballistic chart

WOW!

Thanks for the replies.  Just surprised me it would be that much.

More than two years ago someone was kind enough to send me an excel sheet of all the powders and  bullet manufactures by weight reloading reference materials. To build from. Can someone please help me again, i had to get a new computer after a crash. It was awesome had all the brands and load info. Thank you.

If you're successful, would you mind sharing it with me?

Yes , sure as long as its allowed.

Has anyone tried using a 10" miter saw with a non-ferrous blade to trim 5.56 cases? I have one of Zep's case trimmer mounts and would like to know before I buy a small underpowered bench saw.



+

I wish I had looked at those homemade jigs before buying the Zep. It's a nice piece and has a quick change feature to it but the jigs with 10 cases lined up for the band saw are very nice. I have been wanting to buy a band saw but would like to make sure the bench top models that are usually used on wood will work with a metal blade.

The jig would be clamped or screwed to the miter saw's table area and hands would be away from cutting surfaces.

I use the Harbor Freight saw with Zepp's jig.  It isn't "underpowered" for this application.  In fact, I would caution you to use eye protection with this particular setup - the trimmed ends can go flying with a LOT of force.  I'm working on a shield to keep the necks from trying to get into the next timezone when I do my next batch of cases.  The jig, by the way, works very, very well.

Yes, the saw will get warm, but mine has never lugged or gotten really hot.  You will want to make sure your blade stays sharp, and a little wax on the blade won't hurt with that.

Being frugal, I also tried to use my miter saw to cut some cases. Not a great idea. Cuts were ugly, and some parts went supersonic across my garage.

The bandsaw works for me also, mostly because I already had it.

The mini saw with a good jig is reported to work well.

Thanks guys. If I can't find a good deal on a band saw I will get the mini saw.

Hornady 208 gr A-MAX
COL 2.250
Wolf Small Rifle Magnum Primer
H110 9.0 gr
Average fps: 981.5

fired from 8.5" barrel 1:8 twist

Does anyone else have an issue with A1680 powder and static? The powder does not stick to my scale pan or the funnel but it is sticking badly to the case mouth, not all of it drops down to the base. It may not be an issue but I would prefer to seat the bullet on a clean brass surface. Maybe I can rub the cases on dryer sheets??