SubSonic 300 Blackout

slickyboyboo said:
The original pics are of the 190s, but I've since switched to the 200s, just because of availability. Paul turns batches of the 190s and 220s once a month, he turns the 200s weekly.
Click to expand...
Interesting, I was wondering why the 200s seemed to always be available. I use the 200s, but have though about stepping up to the 220gn.

I've been looking for Alliant Steel and 700X but haven't caught any yet. He was great, called him and he gave me AR and bolt gun loads off the top of his head right there and both worked exceptionally well.
 
QuietTexan said:
Interesting, I was wondering why the 200s seemed to always be available. I use the 200s, but have though about stepping up to the 220gn.

I've been looking for Alliant Steel and 700X but haven't caught any yet. He was great, called him and he gave me AR and bolt gun loads off the top of his head right there and both worked exceptionally well.
Click to expand...
QuietTexan what do you suggest for AR, 7 Twist 16" barrel, around the 200+/- grain for subsonic and around the 110+/- grain for supersonic. This would be for Texas hunts
Thanks
 
For subsonics from an AR I really only had consistent cycling with A-1680, that highly outweighed overall quietness (LG would probably win that) or top end speed. I like H110 for supersonics - IMR 4227 and LG would compress sooner. Still might have to use a drop tube to really pack the cases though.

I'm primarily shooting a BCM 9" upper, full auto carrier, Omega 300 suppressor, whatever the standard BCM spring is, and pretty sure it's an H3 since that's what BCM recommends for their port size. A lot of variables to consider for ARs.

Starting at 12gn of 1680 and backing down will get you there for the subs pretty fast. I ended up at 11.2gn A-1680 for 200gn going 1050 FPS, and 11.8gn A-1680 for 220gn going 1000FPS. You'll probably be about .2gn lower for the same speeds, but cycling will be dependent on the rest of the set up. I cared more for cycling reliably than speed, mainly because I was so frustrated after using H110, IMR 4227, SW Blackout, CFE BLK and LG and having very inconsistent results even messing with the buffer weights.

110gn supers start at 18gn for H110 and move up. You'll probably be good at 19.5-ish gns, if you push it you might hear a crunch around 20 depending on what exact bullet you're using. You have a 16" barrel so you should get good velocity without compressing with a 110gn bullet.

I've been seeing H110, IMR 4227, and Blackout dropping regularly the last couple of weeks. 4227 has been staying in stock over night several places, so it's a good time to be shooting subs.
 
QuietTexan said:
For subsonics from an AR I really only had consistent cycling with A-1680, that highly outweighed overall quietness (LG would probably win that) or top end speed. I like H110 for supersonics - IMR 4227 and LG would compress sooner. Still might have to use a drop tube to really pack the cases though.

I'm primarily shooting a BCM 9" upper, full auto carrier, Omega 300 suppressor, whatever the standard BCM spring is, and pretty sure it's an H3 since that's what BCM recommends for their port size. A lot of variables to consider for ARs.

Starting at 12gn of 1680 and backing down will get you there for the subs pretty fast. I ended up at 11.2gn A-1680 for 200gn going 1050 FPS, and 11.8gn A-1680 for 220gn going 1000FPS. You'll probably be about .2gn lower for the same speeds, but cycling will be dependent on the rest of the set up. I cared more for cycling reliably than speed, mainly because I was so frustrated after using H110, IMR 4227, SW Blackout, CFE BLK and LG and having very inconsistent results even messing with the buffer weights.

110gn supers start at 18gn for H110 and move up. You'll probably be good at 19.5-ish gns, if you push it you might hear a crunch around 20 depending on what exact bullet you're using. You have a 16" barrel so you should get good velocity without compressing with a 110gn bullet.

I've been seeing H110, IMR 4227, and Blackout dropping regularly the last couple of weeks. 4227 has been staying in stock over night several places, so it's a good time to be shooting subs.
Click to expand...
Thank you QT for such a comprehensive reply. Mine is a CMMG I bought during Obama years. I shot 208 (sub) and 110 (suler) reloads from Freedom munitions without a problem. Hornady was popping the primers. I do use the suppressor, but it cycled without it. Took a couple of higs with the 208

Never reloaded for this before. I have the primers, H110 and IMR 4227. Just need the bullets. Might wait till it cools down.
Again. Thanks
 
Glad to help out, hope you get something that works for you. I really like the Makers 200s for hunting rounds, they're in stock and ready to go, and I have not yet (fingers crossed) had any feeding issues with them.

Powder Valley and Midsouth have Accurate 1680 in stock right now, I love how a couple pounds goes a LONG way for loading subs:
www.powdervalleyinc.com

Accurate 1680 Smokeless Gun Powder

www.powdervalleyinc.com www.powdervalleyinc.com
www.midsouthshooterssupply.com

Accurate No. 1680 Smokeless Powder (1 Lb)

Accurate No. 1680 Smokeless Powder (1 Lb) by WESTERN & ACCURATE POWDERAccurate 1680 is an extremely fast burning, double-base, spherical rifle powder that is well suited for large capacity, high performance handgun cartridges such as the 454 Casull, 460 S&W and 500 S&W. 1680 is also an...
www.midsouthshooterssupply.com www.midsouthshooterssupply.com
 
Last edited:
QuietTexan said:
Interesting, I was wondering why the 200s seemed to always be available. I use the 200s, but have though about stepping up to the 220gn.

I've been looking for Alliant Steel and 700X but haven't caught any yet. He was great, called him and he gave me AR and bolt gun loads off the top of his head right there and both worked exceptionally well.
Click to expand...
Both Alliant Steel and 700x did well for me, but I ended up settling on 700x, as it gave better consistency in SDs than steel did. I will try both again when temps cool back off, but I have enough 700x for
~6K subs.
 
Yup. And takes ~4-5gns a round so a pound lasts a lot longer than a brick of primers. Most pistol and shotgun powders will work in the 300 BLK, it's really a matter of what bullet you're shooting and if you need gas to cycle the bolt. I've been aggregating a lot of data from around, and 700X specifically seems to work well with subs using lighter bullets. I shoot a lot of 30 cals, so the 300 BLK is a great way to use up random .308 cal bullets .

150gr FMJ: 700X 4.7gr = 901 fps, 5.2gr 1064 fps

165gr/170gr: 700X 4.2gr = 989 fps
Click to expand...
 
Last edited:
asd9055 said:
Thank you QT for such a comprehensive reply. Mine is a CMMG I bought during Obama years. I shot 208 (sub) and 110 (suler) reloads from Freedom munitions without a problem. Hornady was popping the primers. I do use the suppressor, but it cycled without it. Took a couple of higs with the 208

Never reloaded for this before. I have the primers, H110 and IMR 4227. Just need the bullets. Might wait till it cools down.
Again. Thanks
Click to expand...
I have some of the Lehigh 194's I can part with. PM if you're interested.
 
Warning! This thread is more than 4 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Similar threads

G
300 blackout
Replies
2
Views
1K
Gord0
G
Elk868
300 win mag subsonic
2
Replies
26
Views
12K
MRMAJESTIK
M
R
.300 Blackout dies
Replies
2
Views
927
Wado
W
Stugots
300 Blackout Sub Load
2
Replies
23
Views
1K
marksman1941
marksman1941
Heather
Top Brass 300 blackout
2
Replies
17
Views
3K
Termite I
T

Recent Posts

Top