Sub Sonic Load for 300BLK Out using 180 and 185s???

[Raptor]

Anyone have a good starting point for powders and loads for the 180s for sub sonic loads in a BLK Out??? Lot of info on the 200 and 220s. Thanks guys!!!

 

[RDA72927]

(I'm assuming an AR-15) The issue is having enough pressure to operate the system, that's why there is so much info on 200+ bullets. I had to try 3 different powders to get a 230 to run the system and stay below 1050fps. I could be real tuff to get 180's to make that pony run right..

 

[Bogusname]

9.8 grs of imr 4227 or aa1680. That’s with palmetto projectiles 203 gr pills. 7-1/2 barrel suppressed. Tubb flat spring and h3 buffet I think. Summer or winter subsonic. Not match winner accurate but fun.

 

[dellet]

Depends on what and how you are shooting it from.

Barrel length, gas system, buffer weight, suppressed or not, will make a big difference in powder choice. Even bullet choice might make a difference in powder choice based on case fill and available capacity.

Sierra has some of the best published data.
https://sierrabulletsblog.com/2017/12/21/sierra-bullets-300-aac-blackout-load-data/

Vihtavouri also, N110, N120 are hard to beat for cleanliness suppressed and are a very quiet powder. N120 is very easy to work with.
https://www.vihtavuori.com/reloading-data/rifle-reloading/?cartridge=19

 

[orbitup]

Most say you can't get an AR to cycle reliably with a bullet lighter than 200gn. I was able to get a 190gn bullet to work in my 8.3" barrel with 4227. I don't think I could go any lighter though.

 

[dellet]

Most say you can't get an AR to cycle reliably with a bullet lighter than 200gn. I was able to get a 190gn bullet to work in my 8.3" barrel with 4227. I don't think I could go any lighter though.

“Most” would be wrong.

With short barrels it’s easy, suppressed you can really drop bullet weight. Carbine gas and longer barrels it takes a little playing around. At 168 grains in a carbine gassed system it gets interesting without a suppressor, at 150 grains its a challenge in an 18” barrel to keep them subsonic. But possible.

8” barrel, suppressed, 125 grains is reliable, 110 is possible, but it runs so dirty that it’s not reliable. Not enough pressure to burn the powder.

It’s really all about powder selection.

 

[#40Fan]

Enforcer for 175 grain is the trick in a 10.5".

 

[1shot]

I'm shooting 180 gr. suppressed with AA1680 and it works fine.

Lloyd

 

[Lefty Trigger]

This ^^^ AA1680 is awesome and so is CFE BLK.

 

[1shot]

This ^^^ AA1680 is awesome and so is CFE BLK.

I haven't had the opportunity to try that yet. What can you tell me about it?
Thanks,
Lloyd

 

[dellet]

CFE BLK, kinda missed the mark as a sub-sonic powder. It will cycle anything because it creates a lot of gas, but that's the problem. It tends to be dirty, blows a lot more gas back in your face and comparatively loud suppressed. It doesn't produce a lot of pressure and does not burn all that well because of that.

It tends to have higher ES numbers until you get 100% fill or some compression. With lighter, shorter bullets at low velocity, that becomes a problem.

Here's two different rifles at 50 yards with about a 200 fps ES., two different rifles.
208 Amax
11.2 grains
2.255"

Left hand target was the 208 pushed into the powder, right hand was a 150 grain .

The more you compress CFE, the better it works.

It's hard to beat N120 as a sub powder in that bullet weight range, It's clean, quiet and has an anti-fouler.

It has a better fill rate as it is a bit less dense and generally takes a bit more powder to reach the same velocity, so you end up with a better fill ratio and lower ES numbers. That's important past 50 yards.

 

[wedgy]

Check Lehigh Defense's site for the 194 Maximum Expansion bullet in .308, they have several good sub loads.

https://www.lehighdefense.com/pages/lehigh-defense-load-data-library