300 Blackout reloading.. HELP

[Kristian14]

I just received my tax stamp and picked up my suppressor for my 300 blackout last week and ammunition is still scarce, so I have decided I'm going to start reloading some rounds. My brother-in-law reloads so I'll use his press and and everything but I have a few questions I was hoping someone could help with. As far as the material I need to get started is there a certain type of 300 blackout dye I have to get? My gun is on an AR platform.. And I know I need the dye, casings, powder, primers, and bullets, but is that everything? Also im having a lot of trouble finding websites that sell 300 blackout bullets so if hall have any suggestions it would really help wanting to load mainly 200-220 gr subsonic FMJ (Probably) bullets but will also load a few subsonic hunting rounds as well. Where can I find them?

 

[mcb]

For plinking bullets I would look at Berry's plated. They do several weights including 200 & 220 gr. Affordable and ready and clean to work with.

For hunting try Maker Bullets. They specialize in all copper constructed bullets and have a large variety specifically designed for subsonic velocities and the 300 BO.

Hodgdon online website has good data. For the Maker Bullets use the data published on the bullets page. Their 220gr Rex bullet loaded to their recipe works excellent.

 

[n2omike]

Powder Valley has 500 packs of Berrys 220 grain copper plated bullets IN STOCK for $118... which is a good deal. Coated lead bullets often need the case mouth expanded for insertion and lightly crimped back after the bullet is seated. If not, the bullet/coating can get shaved. Unplated bullets also tend to lead suppressors more than plated. However, lead and coated lead bullets are cheaper, and many find them worth the extra steps. Missouri Bullets has a nice coated 245 grain offering for a good price.

Video featuring the Missouri Bullet 245 grain 300 Blackout offering and loading tips.

 

[Lennyjoe]

I’ve used 208 gr Hornady BTHP and 1680 with great results in my .300 BO suppressed SBR. Also use 190 gr Sub-X with 1680 as well.

Haven’t tried Berry’s yet but others use them with good results.

I use Hornady dies for reloading the .300 BO. Before brass became readily available, I was cutting down and resizing 5.56 LC brass to feed my BO using the Hornady die as well.

 

[Airborne Falcon]

I use the 240 grain Missouri coated flat nose bullets and love'em. I also use the Berry's 220s. I wouldn't use the Berry's for home defense though.

Best deal on brass, when they have it, is from Top Brass 250 ct.

Any good standard rifle primer will do. Some claim you have to go with magnum primers when using some of the hotter powders ... I've never had an issue with it either way. I do have one load that I worked-up that I use Wolf Magnum SRPs ... but I don't use that load out of my pistol length 9" Virtus. It's strictly a pig load that I run through another platform with an 18" barrel.

I use a Q Thunder Chicken on the 9" SIG MCX Virtus and love the thing. My home defense loads are 194 Grain Lehigh Max Expansion and I run them slightly less that 1000 fps .... weapon functions flawlessly and the round expands into this perfect almost starfish shaped thing that leaves a massive would cavity. (Maker makes an almost identical riund, they are just as good imho.) Best thing is that this load whisper quiet, Hollywood quiet, through the Thunder Chicken. Probably the finest can I own.

There are so many great things that you can do with 300 BLK. I recommend investing in the latest Hornady and Speer manuals and also watching some good videos on YouTube. I use a Lee 30 cal factory crimp die to crimp ... but you have to work your way into that.

My favorite die sets are Redding and RCBS but Dillon, Lee, Lyman and even Hornady all make good dies. I'd try to go with Titanium Carbine (T/C) if you can find a set. 300 BLK loads more like a pistol cartridge than rifle imho.

Powder selection just depends. Someone suggested downloading the Hodgdon and VihtaVuori apps ... that is a great bit of advice. Sierra has a free app as well. I personally love 1680.

Good luck, awesome and fun load ... especially with a good can.

Which supressor did you go-with?

Final thoughts .... when working-up a good 300 BLK subsonic load sometimes it is imperative to know your velocities. You're trying to stay below 1050 fps while still cycling your weapon reliably. Chronographs help. You can guess by sight and sound but having a chronograph takes a lot of the guesswork out of the process. Some of the heavier softer cast projectiles and solid copper designs are built to expand at velocities well below 1050 ... like even 900-950 fps. Those are my favorites because they still get good penetration and expansion at those speeds ... and they cycle my weapon reliably. Each platform is different. My SIGs have a selector switch -/+ gas value system and these types of gas systems are becoming more and more popular and make reloading for 300 black so much easier when it comes to functionality.

Lastly, use dedicated 300 BLK mags. 5.56 mags may function fine when using the light weight projectiles, but once you get into the 150+ projectiles they are not going-to move through the 5.56 mags reliably. So get yourself some dedicated 300 BLK mags and mark them so that you never confuse them with 5.56 in low light.

 

[kcofohio]

I have used the Missouri's bullet with good results. Used 12.0 gr. Reloder 7, OAL 2.100". That gave 1060ish fps out of a 8.5" barrel.
The Lee Universal Expander works well for a lead in the case to prevent shaving. The Lee collet crimp dies has worked well for removing the expanded case mouth.

AA1680, IMR4198, CFE-Blk, Reloder 7, and possibly 300-MP, should work with subs in the AR platform.

 

[dgod]

i am a FIRM believer in the 200, 212, and 220 grain ELDX bullets when loaded in suppressed 300 BLKOUT ammo. I use them in my 10.5” AR lookalike and it works great.

 

[mcb]

I have used the Missouri's bullet with good results. Used 12.0 gr. Reloder 7, OAL 2.100". That gave 1060ish fps out of a 8.5" barrel.
The Lee Universal Expander works well for a lead in the case to prevent shaving. The Lee collet crimp dies has worked well for removing the expanded case mouth.

AA1680, IMR4198, CFE-Blk, Reloder 7, and possibly 300-MP, should work with subs in the AR platform.

IMR 4227 under the Berry's 220gr is super quite yet still produce enough gas to cycle both my 9-inch and 5-inch AR pistols.

ETA: I have yet to see better terminal performance from a bullet for 300 BO subsonic than the Rex bullet from Maker Bullets.



I have fired them through 12oz Gatorade bottle and had full expansion before it exited that little bottle. They thump the armadillos very nicely. The only drawback to them is they need a 300 BO specific magazines to feed well. I am using D&H and Lancer 300 BO specific magazine with great reliability. That also help keep the 556 and 300 BO separate.

 

[Lennyjoe]

One other piece of advice, an adjustable gas block might be a good addition to your rifle.

 

[Lennyjoe]

My PD load for my 10” barreled .300 BO with AAC Cyclone suppressor. 11.9 gr of 1680 ~1060 FPS.

 

[EricBu]

I load a couple thousand a year to shoot through my suppressed AR's. I use both dillon dies, and RCBS small base dies. 220 berry's plated are the best plinking option out there, followed by Gallants 217 BT coated cast. The berry's are in stock direct from their website right now. I have run these as short as 2.14 and as long as 2.23, over 9 to 10 grains of H110 or 10 to 11 grains of RL7. RL7 is my favorite, but it doesn't meter great. H110 meters well, but has a tad more flash. Where you end up with will have a lot to do with your particular gun and whether you want it to run with and without your can, how long your barrel is, and whether you are running 300 BLK purpose built PMAGS (GI mags take a lot of OAL playing around to get them right with big bullets). For more expensive, but far more accurate fun, the Sierra SMKs are great bullets, and basically the same load data with a bit of tweaking.

 

[mcb]

I load a couple thousand a year to shoot through my suppressed AR's. I use both dillon dies, and RCBS small base dies. 220 berry's plated are the best plinking option out there, followed by Gallants 217 BT coated cast. The berry's are in stock direct from their website right now. I have run these as short as 2.14 and as long as 2.23, over 9 to 10 grains of H110 or 10 to 11 grains of RL7. RL7 is my favorite, but it doesn't meter great. H110 meters well, but has a tad more flash. Where you end up with will have a lot to do with your particular gun and whether you want it to run with and without your can, how long your barrel is, and whether you are running 300 BLK purpose built PMAGS (GI mags take a lot of OAL playing around to get them right with big bullets). For more expensive, but far more accurate fun, the Sierra SMKs are great bullets, and basically the same load data with a bit of tweaking.

Try IMR-4227 under the Berry bullets. It is noticeably quieter than H110.

 

[EricBu]

Try IMR-4227 under the Berry bullets. It is noticeably quieter than H110.

I can get H110 20-50 lbs at a shot..not so much 4227. What I'm really waiting for his Lovex powders and their Shooter's World cannister variants to come back into stock. Shooter's World Heavy Pistol is fantastic in blackout, meters well, and I can get a pallet of it at around 8 bucks a lb.

 

[n2omike]

Try IMR-4227 under the Berry bullets. It is noticeably quieter than H110.

DEFINITELY! I tried H110 (W296), then 4227, and you could literally hear the buffer spring with the 4227 in a 10.5" barrel and lower level can. I also tried CFE BLK and it was loudest of all. This was subsonic with Berrys bullets.

Speaking of Berrys... On the Berrys site and most others, they are $150/500. At Powder Valley they are $117 and were in stock when I checked yesterday. I bought two 500 packs. I get great accuracy out of them. Doing velocity testing with a target at 50 yards, most of the bullet holes are touching each other. Complete upper is a PSA they have in stock for $429. Ran a couple hundred rounds with various powders and 100% function even at lower velocities, regardless of powder. Using the 300 specific mags.

LOVE shooting it subsonic at metal targets! An absolute BLAST and tons of fun!

 

[Airborne Falcon]

The Lee Universal Expander works well for a lead in the case to prevent shaving.

I've been meaning to order one of those for years. I've been using a 338 MX expander die to expand 30 cal mouths and it has worked fine for years ... but the Lee Universal would probably be the more apropos solution. I've got a buddy who has one and he swears by them although he said they bottom out on 45-70 and really don't-do that cartridge well, he said 45 ACP and 45 Colt are covered ... just not .458

 

[Airborne Falcon]

Powder Valley has 500 packs of Berrys 220 grain copper plated bullets IN STOCK for $118... which is a good deal. Coated lead bullets often need the case mouth expanded for insertion and lightly crimped back after the bullet is seated. If not, the bullet/coating can get shaved. Unplated bullets also tend to lead suppressors more than plated. However, lead and coated lead bullets are cheaper, and many find them worth the extra steps. Missouri Bullets has a nice coated 245 grain offering for a good price.

Video featuring the Missouri Bullet 245 grain 300 Blackout offering and loading tips.

That's a good video. That's almost the exact same bullet I get from Gallant Bullets.

 

[Swampman]

@ Kristian14
What length gas system and barrel does your weapon have?

If you're going to shoot mostly subsonic, starting with a pistol length gas system will save you a lot of frustration.

I cast and powder coat all of my 300 Blackout heavy subsonic bullets. I started out with the Lee 230 grain 5R mold but have pretty much abandoned it in favor of the MP Molds 235 grain Hollowpoint due to better accuracy and increased terminal performance on hogs.

Keep in mind when hunting with 300 BO subsonics that your energy levels are going to be about like a hot loaded .45 ACP, so good bullet placement and shot angle are extremely critical.

 

[Jesse Heywood]

For dies, I recommend the small base die. Gives better feeding in SA guns. Buying 300 brass simplifies the process, but converting 223 brass is cheaper. For more info go to www.300blktalk.com/forum/index.php

 

[Klaatu Barada Nikto]

I developed a great load using Sierra Match King 190g 308's. They are HPBT's.
Using AA1680 at about 11.2 to 11.3
In an AR Pattern rifle you will want a heavier buffer, possibly an H2 or H3 and a light duty spring with an adjustable gas block.
Starline Brass is very nice, can be costly but they seem to last for many cycles.
As a shouldered rifle round (the shoulder is very minimal) with such low velocities I have found the brass grows very little and seems to last.
One last item to ponder. Often an AR with a sub round will have trouble cycling the round without the supp mounted, but with it mounted the increased gas pressure makes it cycle just fine.
Good luck and get ready for pellet rifle noise levels!

300_ACC_Blackout_Data.pdf

 

[BW460]

Everything you ever wanted to know is at www.300blktalk.com.

 

[Airborne Falcon]

@ Kristian14
What length gas system and barrel does your weapon have?

If you're going to shoot mostly subsonic, starting with a pistol length gas system will save you a lot of frustration.

I cast and powder coat all of my 300 Blackout heavy subsonic bullets. I started out with the Lee 230 grain 5R mold but have pretty much abandoned it in favor of the MP Molds 235 grain Hollowpoint due to better accuracy and increased terminal performance on hogs.
View attachment 1029533
Keep in mind when hunting with 300 BO subsonics that your energy levels are going to be about like a hot loaded .45 ACP, so good bullet placement and shot angle are extremely critical.

That MP mold looks pretty sweet. I've been looking for something like that .... thank you. Much appreciated.