300 Blackout load data and questions

[dellet]

Sierra Bullets 300 AAC Blackout Load Data

Test Specifications/Components Firearm Used: Universal Receiver Barrel Length: 16″ Twist: 1-8’’ Case: Hornady Trim-to Length: 1.363″ Primer: Winchester WSR Remarks: The 300 AAC Blackout…

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[localbrew]

I'll be using Berry's 220gr bullets but I'm clocking C.O.A.L. 2.172" I think starting at 12.1 and working down is the most reasonable. I will like hit super since I'm running suppressed but we'll see

 

[Konocti's Wigwam]

See dellet's comment above; doesn't sound like Hodgdon is that great in terms of their data. I think you'll just get super sonic if you go over the 12.2 range like some have reported. Other things will increase the velocity as well, crimp, suppressor etc.

I don't think it works like that. If you're using a 220 grain bullet with 12 grains, you're gonna be shooting subsonic. For supersonic you're gonna need a 110gr - 150gr projectile and your load will be about twice that.

 

[localbrew]

It most certainly does work like that, and that is the versatility of CFE BLK. As soon as you hit 1100 ft. per second you're super

 

[Konocti's Wigwam]

It most certainly does work like that, and that is the versatility of CFE BLK. As soon as you hit 1100 ft. per second you're super

Where exactly are you pulling these numbers out of? Everyone's barrel and load acts slightly differently.

If you chrono'd those numbers, you're good to go.

 

[dellet]

I don't think it works like that. If you're using a 220 grain bullet with 12 grains, you're gonna be shooting subsonic. For supersonic you're gonna need a 110gr - 150gr projectile and your load will be about twice that.

Actually it works exactly like that.
Look at Hodgdons max load and pressures for a 200 plus grain bullet. Nothing above around 25,000 psi. The SAAMI max pressure is 55,000 psi. Your leaving 30,000 psi and a huge amount of velocity untapped.

The biggest problem is that there are tens of thousands of shooter such as yourself, that if using a 7” barrel end up with subsonic loads so anemic that even designated expandable sub sonic bullets won’t expand. Simply because they see”max load” when it should read max velocity. Leaving 4 grains of powder off the table because 12 grains in a 16” is labeled “max” when by pressure, that translates
Into any barrel length is 16 grains.

It’s just a stupid way of listing maximum. And most manufacturers are guilty of it.

This is what I mean when I say you have to be smarter than the load manuals. You have to understand what you’re doing, not just assemble according to the numbers.

 

[localbrew]

Where exactly are you pulling these numbers out of? Everyone's barrel and load acts slightly differently.

If you chrono'd those numbers, you're good to go.

Checkout the previous poster on page 1 and yes barrel length, twist, etc. Point being I'll start around 12.1 and see if they are sub or super at that load and work back from there, but 220gr can in fact go super.

 

[Konocti's Wigwam]

Actually it works exactly like that.
Look at Hodgdons max load and pressures for a 200 plus grain bullet. Nothing above around 25,000 psi. The SAAMI max pressure is 55,000 psi. Your leaving 30,000 psi and a huge amount of velocity untapped.

This is also effected by seating depth. With 12 grains of powder you won't even be close to supersonic levels, unless you're considering anything over 1100 fps as supersonic. Should be able to get about 2300 fps otherwise.

Hodgdon has load data for CFEBLK. Anything short of running a chrono on it is purely playing mental masturbation, IMO.

EDIT: and just to be clear, you can do all the testing you want but without running a chrono on your load you will never actually know the velocity.

 

[dellet]

It most certainly does work like that, and that is the versatility of CFE BLK. As soon as you hit 1100 ft. per second you're super
View attachment 1474304

I don’t know if you’ve tried this, but I would take that 11 grain load and start shortening the COL. Your groups started tightening up and the SD started settling in. Most likely due to higher load density.
Get the base of the bullet in the powder. The higher load density will push the velocity back up. The SMK is incredibly jump tolerant, use that to your advantage.

 

[dellet]

This is also effected by seating depth. With 12 grains of powder you won't even be close to supersonic levels, unless you're considering anything over 1100 fps as supersonic.

Hodgdon has load data for CFEBLK. Anything short of running a chrono on it is purely playing mental masturbation, IMO.

Well anybody serious about developing a subsonic load without a chronograph is a damn fool anyway.

There is nothing magic about 12 grains. It’s an arbitrary number pulled out of the air. Unless it’s tied to pressure.

My CFE load for a 208 AMax is 10.5 grains clocks in around 1060 in an 18” barrel, 1020 in an 8”. I can go super at 11 in either barrel, a full grain under your magic 12. It’s all about manipulating the pressure curve and burn rate of the powder.

If you’re going to shoot 300 Blackout and can’t think for yourself, it’s going to be a disappointing cartridge.

Something about a 175 SMK from 900-2300fps in a 24” barrel, kind of makes you see some potential.

 

[Konocti's Wigwam]

Well anybody serious about developing a subsonic load without a chronograph is a damn fool anyway.

Amen. I have done it in the past, but just got one recently of my own. I've used friends in the past, but have never verified the actual loads myself. Too much changing, load, seating depth projectile, etc...

I guess I'm just tired of feeling like I lick my finger and hold it in the wind.

 

[6Creed73]

Not a very good approach, the Hodgdon site shows 12.1 grain as max for a 220 grain projectile.

Hodgdon also used at least a 16" barrel for their data, not a 9" barrel. I go by my real world experience, not the Hodgdon data. With my 8.5" barrel, A 220gr projectile will get me just under 1100 fps with 12.3gr. 12.5gr was a suggested starting point to work down from. There is almost no chance of over pressure.

The Hornady data for CFE-BLK for a 190gr projectile is 12.4gr for 1100...which is why I said start there and go down.

If you have some actual experience with the topic, share it. I've been loading 300BLK for years.

 

[Konocti's Wigwam]

If you have some actual experience with the topic, share it.

That's the whole point. Nobody should be sharing anything. Use a chronograph and know what you're loading in the cartridge. I will chrono my own data, and my data alone as there are too many factors to get accurate numbers. If your method works for you, you should keep using it. Unless you loaded and tested all 7 of those, it's all crapola.

 

[6Creed73]

That's the whole point. Nobody should be sharing anything. Use a chronograph and know what you're loading in the cartridge. I will chrono my own data, and my data alone as there are too many factors to get accurate numbers. If your method works for you, you should keep using it. Unless you loaded and tested all 7 of those, it's all crapola.

What's my method? Did I say I don't use a chronograph? I chrono every single load I develop, including 300BLK. If you are loading subs it's pretty much a requirement.

Again, 12.5gr is a safe starting point regardless of his barrel length or any other factors. You said it was a bad suggestion and have yet to say why. That's what load development is...working a load up or down in this case. Considering the chances of over pressure at 12.5gr is about 0%....Can you elaborate as to why it's a bad approach? Or are you just here to argue?

And that's funny saying that the load data is crapola since it was you who cited load data to tell me my approach was bad, lol

 

[Konocti's Wigwam]

What's my method? Did I say I don't use a chronograph? I chrono every single load I develop, including 300BLK. If you are loading subs it's pretty much a requirement.

Then why would you expect me to use your data? I should chrono it just like everyone else. If we all do that, what does it really provide those who do chrono their loads?

Seems it only helps people that don't chrono their loads, in a deceitful way, since their loads can and will be different.

 

[6Creed73]

Then why would you expect me to use your data? I should chrono it just like everyone else. If we all do that, what does it really provide those who do chrono their loads?

Seems it only helps people that don't chrono their loads, in a deceitful way, since their loads can and will be different.

You realize it's a starting point right? Funny thing about load development, before you can chrono anything you have to actually load up some rounds. If you know of a way I can chrono my loads prior to having to make an educated decision on a starting load, I'm all ears...that would be pretty sweet.

I didn't tell him he should use my load data, did I? I suggested a safe place to start. Are you suggesting that handloaders should not share that information? You may want to stay off the the reloading forums, because they are filled with people sharing ideas.

 

[6Creed73]

I'll be using Berry's 220gr bullets but I'm clocking C.O.A.L. 2.172" I think starting at 12.1 and working down is the most reasonable. I will like hit super since I'm running suppressed but we'll see

View attachment 1474293

I typically shoot my 8.5" 300BLK suppressed as well. I see very little velocity increase when shooting suppressed vs not supressed...maybe 10-15fps averaged.

My guess is you'll be subsonic at 12.1, but your testing will prove that out. I like to get my subsonic loads as close to 1050 as possible and only leave a little room before hitting 1100 for margin of error. With that said, I struggled with ES using CFE-BLK, so I'd probably target 1025 if I was working a load with it. So your starting load will also depend on what your goal velocity is. I use mine for coyotes sometimes and like to be on the higher end of subsonic for expansion.

Here is a load I'm working on for a 190gr Sub-x with A1680. With an ES of 20 over 10 shots I know I'm good to go and probably won't mess with it anymore. But who knows...I like to tinker

 

[localbrew]

Thanks @6Creed73 this primarily a range SBR for running drills outside. It does have a place next to my bed but that application I'm using Underwood's defense ammo - 194gr subs (max expansion) that meter at 1025 fps.

I appreciate all the help to get my starting load and tweak from there

 

[6Creed73]

Thanks @6Creed73 this primarily a range SBR for running drills outside. It does have a place next to my bed but that application I'm using Underwood's defense ammo - 194gr subs (max expansion) that meter at 1025 fps.

I appreciate all the help to get my starting load and tweak from there

I use my 300BLK SBR as a home defense gun too. It's a great round and super fun to load for.

 

[MSS]

Any luck with W 296? Seems like it would be good sub and super. I’ve been gradually collecting 300 blk dies and brass etc. I just haven’t pulled the trigger on it yet.