300 blackout reload data question

[Doindia]

Hey all, I just got done loading some 300 blackout to spec from my hornady (10th edition I believe) and the book said OAL was 2.21. After seating at just below that I’m sitting here looking at a bullet that seems like it’s sticking out of the case way too far. I went and compared it to some subs I had 200gr and also some 147gr factory loads. It was taller/longer than all 300 factory loads I have on hand. I just wanted to get some opinions or possible load data from someone else’s book (I know I need more resources)

the stats:
1. 223 brass Lc headstand
2. Cut to 1.365 ish
3. Resized and then trimmed with a 300 blackout pilot.
4. 168gr hornady bthp
5. 13gr of h110

the best I can tell the case prior to projectile insertion seems up to spec on all measurements. I’m posting some pics. The bullet doesn’t look entirely Terrible just waaaay longer than anything I’ve shot!

 

[JPIMBO]

That’s normal I think for that caliber. Very large. Does it fit in your magazine? Don’t 300 Blk bullets get bigger than that? And then subsonic too.

 

[Demi-human]

Looks fine to me.
These are Remington subsonics.

They’re not as long set as my 75 .223s or my single shot 88 Valkyrie load.

If they fit the magazine they should be a go.

 

[Doindia]

That’s normal I think for that caliber. Very large. Does it fit in your magazine? Don’t 300 Blk bullets get bigger than that? And then subsonic too.

Yes they get much larger than that. One of the things that was throwing me off was that grain weights below and above still sat further in the cartridge.

in that picture above is a 147gr as well as a subsonic 200gr bullet. Both of them sit shorter than the 168 I just loaded .

I have checked it with multiple sources and they all agree haha it just looks odd to me. ill try to load a mag and fire some soon.

 

[Doindia]

Looks fine to me.
These are Remington subsonics. View attachment 949354

They’re not as long set as my 75 .223s or my single shot 88 Valkyrie load.

If they fit the magazine they should be a go.

I hope to be able to load and shoot some of these soon. The wife is out of town this weekend and my 16 month old is making light work of me over here hahaha

 

[Demi-human]

The wife is out of town this weekend and my 16 month old is making light work of me over here hahaha

Don’t let them smell any fear, Dad! They are like wolves, they sense weakness and it gives them power!
My Mini-Amazon just got back from DeVos for a checkup. She’s ten and 5’3”! I’m getting a little worried.
When she’s sixteen she’ll be big enough to take the car keys from me!

Another thing that may make the seating depth look off, some have a cannelure. To hit it, they must be seated deeper.
The subs are also sometimes seated deeply to take up combustion space for a more effective burn of the small charge it takes to get them below the speed of sound. A big empty case makes for more variation in ignition and speed.

I hope to be able to load and shoot some of these soon.

Let us know how they do.
I have yet to make any Blackout ammunition, I waited too long. Now isn’t the time to start a new cartridge.

And being thoroughly enamored with my Bushmaster.

 

[Doindia]

Hahahahaha smell the fear is right!


I was a little intimidated by the process initially but it’s so simple with the right tools. I’m picking up cheap 223 brass from the forum here and 308 dia projectiles are up but not outrageous so it’s not a terrible cartridge to fire up!