300 Blackout Powder choices for pistol / SBR

[Schoolboy]

So thanks to missing out on PowderValley's free hazmat yesterday My mind started churning as to what other powders I should sample/stock up on as I find deals on them. The Delivery system (once assembled) will be a AR pistol with a 10.5" barrel, most likely wearing a suppressor. I am currently envisioning up to 5 loads with 3 of them being supersonic; 110gr, 125gr, 150gr-ish, and two of them being subsonic; 190gr sub-x, and a 220gr. I while back I ordered an 8lb jug of H110 to max out my Powdervalley order since I could use it in both my 44mag, and in 300blk. But I just started thinking about case fill with the H110. Will there be a fair amount of unused space in the brass using the H110 and the 190-220gr projectiles? Or are they so long they fill the space once seated? Other considerations are heat generated, and how dirty will it be? This led me to read up on other powders, some being extremely popular simply because they are cheap and they cycle in semi auto rifles. So I have compiled a list of them below to see what you guys have experienced when using them in regards to: case fill, semi auto cycling, heat generation, quietness, temp stable, and cleanliness/unburnt powder.

H110
CFE BLK
IMR4227
Accurate 1680
ShootersWorld Blackout
ShootersWorld Socom
Vihtavuori N110
Vihtavuori N120


Personally the Vihtavuori N120 caught my attention as being well regarded for generating low temps, clean burn, and being the 2nd quietest behind IMR4227 for subs.

[Yondering]

All of those listed work well, along with 296 (same as H110) and Lil'Gun. Don't overthink it too much; if you have H110 already, use that.

It doesn't matter what your barrel length is either; that doesn't affect powder choice other than perhaps being more conscious of flash with shorter barrels, but a 10.5" 300 Blk is pretty standard for these powders.

[hartcreek]

I could add another four or five powders but I would NOT fiddle with different bullet weights to much POA hassles. I have two I use for 300 BO and both are close enough to the same weight I use the same load data. For Practice I use a Lee Mold 90 grain that I also use for numerous .32s and powder coat and size it accordingly. For business I cast in zinc using another Lee mold but for .308/.311 In lead it winds up being 165 grains in zinc 97. It is an aluminum mold so I just carbon it up real well and run it through the sizer wet with water.

[Caveman Jim]

I’ve use number one and two but none of the others. H110 is the same as W296 and I use either one with the same amount of powder with supers (125 HP’s, 150g FMJ’s & 155g HP’s. CFEBLK is also a valid d choice. I have not gone down the rabbit hole with subs because I don’t own or will I ever have a suppressor.
Good luck with your 300BLK rabbit hole.

[mcyclonegt]

1680 is the go to for most the folks I know that shoot 300 BLK, subsonic with a suppressor. Its clean, and fast enough to burn all the way before the bullet hits the suppressor. H110 was a bit dirty for me, so I saved it for magnum pistol.

[Yondering]

1680 is the go to for most the folks I know that shoot 300 BLK, subsonic with a suppressor. Its clean, and fast enough to burn all the way before the bullet hits the suppressor. H110 was a bit dirty for me, so I saved it for magnum pistol.

1680 is generally far more dirty than H110 in the 300 Blk - in either subs or supers.

H110/296 and Lil'Gun are good choices for subs in a properly set up 300 Blk AR, but if your rifle is a little undergassed then 1680 will help, but at the expense of being louder.

And of course if someone is using a bolt action for subsonics, then forget all those powders and be looking at fast pistol/shotgun powders in the range of Unique, Green Dot, Trail Boss, Red Dot, etc; they are much quieter for subs but won't cycle an AR15 without severe and specialized modifications to the rifle.


also, Caveman Jim's comment about not using subs because he doesn't own a suppressor is right on target; there's often a fascination with subs for new 300 Blk owners, but if you don't own a suppressor there's not much point. It still sounds like a gunshot, but with the ballistics of a skinny 45 ACP instead of a rifle round. Along that same line of reasoning, there's not much point in trying to get your AR15 to cycle subsonics without a suppressor - you can do it, there's just not really any reason to, and a rifle tuned to only run subs with the suppressor, but not without, will be a little quieter with the same loads.

[dreadi]

4227 for sub funz

https://youtube.com/shorts/PuFsf8uOyYQ?feature=share



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[beckdw]

My experience has only been with IMR4227 and AA1680. I found the 4227 did not do well for subs with me. I could not get it to cycle and stay subsonic in my 7.5". I switched to the 1680 and all was well. My understanding was it was because the 1680 is a faster burning powder.

However, 1680 is stupid dirty. I've picked up some H110 and Shooters World Blackout to give them a shot but haven't tried them yet.

The H110 is a faster powder even than 1680 so I'm hoping it will work better in my 6" barrels. I'm also hoping it is less dirty.

[MadPick]

My experience has only been with IMR4227 and AA1680. I found the 4227 did not do well for subs with me. I could not get it to cycle and stay subsonic in my 7.5". I switched to the 1680 and all was well.

I had the exact same experience, using 240-grain bullets.

[mcyclonegt]

1680 is the go to for most the folks I know that shoot 300 BLK, subsonic with a suppressor. Its clean, and fast enough to burn all the way before the bullet hits the suppressor. H110 was a bit dirty for me, so I saved it for magnum pistol.

1680 is generally far more dirty than H110 in the 300 Blk - in either subs or supers.

H110/296 and Lil'Gun are good choices for subs in a properly set up 300 Blk AR, but if your rifle is a little undergassed then 1680 will help, but at the expense of being louder.

Interesting. That has not been my experience, however, I have not shot mine a ton. Just enough to get it dialed in and moved on to the next project. I specifically bought 1680 for a supressed 300 with a 10 inch barrel using poly coated 230 grain lead bullets I cast myself. I didn't shoot a ton of H110 because I bought that for Magnum pistols. It's wasn't dirty, the 1680 was just cleaner for me. I did pick up a half pound of 4227 that I will be loading up soon, hopefully.

[Yondering]

My experience has only been with IMR4227 and AA1680. I found the 4227 did not do well for subs with me. I could not get it to cycle and stay subsonic in my 7.5". I switched to the 1680 and all was well. My understanding was it was because the 1680 is a faster burning powder.

However, 1680 is stupid dirty. I've picked up some H110 and Shooters World Blackout to give them a shot but haven't tried them yet.

The H110 is a faster powder even than 1680 so I'm hoping it will work better in my 6" barrels. I'm also hoping it is less dirty.

It's the other way around actually (which is why it worked for you). 1680 is slower burning than 4227, creating more pressure at the gas port. A faster burning powder builds pressure quicker, but also drops pressure off faster on the other side of the peak. Since peak pressure generally occurs long before the gas port is exposed to pressure, even with pistol length gas systems in the 300 Blk, it's the far side of the pressure peak that affects AR15 cycling - a slower burn rate powder that maintains pressure longer generally provides more gas pressure for cycling. To achieve the same velocity (call it 1,000 fps for example), the slower burn rate powder generally creates lower peak pressure, but builds to that peak slower and then drops off slower; more of the burn is happening closer to the gas port than with a fast powder.

I say generally here because burn rate charts are a severe oversimplification, and I don't want to imply that there are no exceptions, but IME it's accurate for this discussion anyway.

All of this also means that the slower burn rate powder makes more pressure at the muzzle too, which makes it louder with more work for the suppressor to do. And that effect is increased further because when an AR cycles harder (due to more pressure at the gas port), it unlocks earlier with higher pressure at the bolt carrier vents and chamber, again making it louder. That's why I play around with different powders for each subsonic AR15 load to find the one that gives me the velocity I need but doesn't cycle any harder than it needs to for reliability - it makes for a quieter (although often dirtier) load.

A more extreme example is using a very fast powder like Red Dot for 300 Blackout subs - it works well and is very quiet, but pressure drops off so fast that by the time the gas port is exposed to pressure, there's not enough there for the rifle to even try to cycle. (And if you want to make the quietest possible loads and intentionally hand cycle the rifle, fast powders like that are a good way to get there without changing anything on the rifle itself.)

As a semi-related side note, it's usually easier to find a good reliable load in 300 Blk subs with jacketed bullets than with cast bullets. The cast bullets offer lower resistance to engraving the rifling, so you can run into a situation where even with slower powders the load generates the velocity you want without enough pressure to cycle reliably. This is where slow powders (for the application) like 1680 and CFE BLK help.
In one of my rifles for example, using the same powder (I think it was with H110) I was able to get 180gr jacketed subsonics to cycle, but had to go up to at least 230gr cast bullets to get cycling. The cast bullets needed that extra weight for resistance to get the powder burning well, while jacketed bullets accomplished that through the engraving force. Just one of those weird little oddities about subsonic loads in a gas rifle that can leave you scratching your head for a bit.

Hope that helps.

[The509busman]

Ive had good uck with h110 and cast 220 coated bullets they are sub i need to run them across a chrono but I know they are sub ( mouse fart quite with a can)

[Schoolboy]

Great info guys!

I am a little surprised no one has tried using either of the Vihtavuori powders though. It seams like every other powder on the list has been tried by you guys.

Yondering, the cast bullets causing issues with velocity and cycling is interesting. I wonder if the copper plated 220gr projectiles like Berry's or Everglades would have the same problem or if they would fall somewhere in the middle?


As some of you have pointed out adding a suppressor into the mix complicates life some but since the 9mm pistol suppressor I have picked out is rated for supersonic 300blk out of an 8" barrel, it will be occasionally used on the 300blk till I settle on a 30cal can to share between the 300blk and my 30-06. But the suppressor use coupled with the 10.5" barrel is what got me wondering if any of these powders really do run cooler and cleaner. I'm all for keeping the hands cool, and the equipment clean. Especially since most 30cal cans are either welded or 3d printed.


Dreadi, every time you post a new video I get a bad case of the "I want that!"

[Schoolboy]

Bringing this back up to the top, but I got my hands on some VV N120, H110 powder. I also managed to snag some berrys 220gr projectiles, speer 125gr TNT's, and American reloading copper 125gr projectiles to work with. I hope to get the pistol built and start testing some of these combos by the summer.

Pics to follow a bit later.