.300BLK Supplies and Thoughts

Wynder · Sep 3, 2019

Hey there, folks!

So, I'm kind of excited...I joined this forum 12 years ago with the intent of getting into reloading, but it took me this long to get into a place in my life where I had the time and resources to dip my toes in!

I'm almost done setting my my Lee Pro 1000 that I have with .300 Blackout dies. My intent is to make subsonic loads (which my Saint AR-15 pistol loves to eat), and I've got a Lyman reloading manual coming in from Amazon shortly -- can't wait to get started in on this!

What I wanted to get thoughts on is anyone who has a solid subsonic load configuration for .300BLK and where they get the bullets for that configuration? I don't necessarily care if they're cast, as long as they're plated/coated... I'm just trying to find a solution that's not going to break the bank. I have a local source for powder and primers, but I haven't find a go-to place that's the best price for bullets.

Thoughts?

kcofohio · Sep 3, 2019

Check out MBCs 245 gr.

http://missouribullet.com/details.php?prodId=204&category=20&secondary=36

I'm just starting with them, having only shot 20 rds. so far. So far they chamber right.

Wynder · Sep 3, 2019

I appreciate that insight! Great price on those... Let me know how they continue to work for you -- I'll have to pick some up and figure out a load for them.

kcofohio said:
Check out MBCs 245 gr.

http://missouribullet.com/details.php?prodId=204&category=20&secondary=36

I'm just starting with them, having only shot 20 rds. so far. So far they chamber right.

Havok7416 · Sep 3, 2019

Missouri Bullet, Acme, Berry's (plated) and Eggelston Munitions all make 200 grain or heavier bullets in .308/.309. There's likely a whole bunch I forgot. You will have to experiment with your rifle to find what it likes best.

Whiterook808 · Sep 3, 2019

You might also check Everglades.

Jesse Heywood · Sep 3, 2019

If you haven't found it, another good forum is www.300blktalk.com

mcb · Sep 4, 2019

I am using two bullets for my 300BO subsonic loads. For plinking Berry's plate 220gr (right). For hunting Makers REX 220gr (left).

kcofohio · Sep 4, 2019

Wynder said:
I appreciate that insight! Great price on those... Let me know how they continue to work for you -- I'll have to pick some up and figure out a load for them.

I'm planning to load up 30 more. Hopefully I can have results by this coming weekend.

FWIW, I figured it out to be about 28 cent per round using the Missouri bullet.

Wynder · Sep 4, 2019

What recipe are you using? Are you loading sub or supersonic?

kcofohio said:
I'm planning to load up 30 more. Hopefully I can have results by this coming weekend.

FWIW, I figured it out to be about 28 cent per round using the Missouri bullet.

Havok7416 · Sep 4, 2019

Wynder said:
What recipe are you using? Are you loading sub or supersonic?

220 and up won't go supersonic.

kcofohio · Sep 4, 2019

Wynder said:
What recipe are you using? Are you loading sub or supersonic?

I'm using Reloder 7. 10 & 10.5 gr. wasn't consistent in locking the bolt back on the last round. 11 & 11.5 gr. did. My next test loads will be 11, 11.5, & 12 gr. of Reloder 7. COAL of 2.100" so far. Hoping to get chrony readings next time out.

mcb · Sep 4, 2019

Havok7416 said:
220 and up won't go supersonic.

Why? You can push 220gr bullets well over super sonic if you want. Not much point since you probably top out in the 1300-1500 fps range but you can definitely push them super sonic if you want. My 16-inch 300BO pushes just about every commercial subsonic ammo I have tried to super sonic velocities.

Havok7416 · Sep 4, 2019

mcb said:
Why? You can push 220gr bullets well over super sonic if you want. Not much point since you probably top out in the 1300-1500 fps range but you can definitely push them super sonic if you want. My 16-inch 300BO pushes just about every commercial subsonic ammo I have tried to super sonic velocities.

The only factory "subsonic" Blackout I have seen is 180 grains or so and definitely isn't actually subsonic.

I suppose I do have a 220 grain bullet that will get just above supersonic now that I think of it.

mcb · Sep 4, 2019

Havok7416 said:
The only factory "subsonic" Blackout I have seen is 180 grains or so and definitely isn't actually subsonic.

Just about all the major ammunition manufactures offer 200gr or heavier subsonic 300 BO ammo. I agree much of it, at least my sampling, has not been subsonic in my 16-inch gun but all of it has been subsonic in my 9-inch gun.

Havok7416 · Sep 4, 2019

I only have a 16 inch barrel myself. Your comment about the difference between the 9 inch and 16 inch barrels is interesting. The common line I am always hearing is that the Blackout doesn't gain much (if anything) by having a barrel longer than 9 inches.

mcb · Sep 4, 2019

Havok7416 said:
I only have a 16 inch barrel myself. Your comment about the difference between the 9 inch and 16 inch barrels is interesting. The common line I am always hearing is that the Blackout doesn't gain much (if anything) by having a barrel longer than 9 inches.

With subsonic ammo the gain is not a lot but enough to make it supersonic.

This is the data I have so far.

My reloads:
Barry 220 gr (10.1 gr IMR 4227) 1040/983.8 fps
Maker 200 gr (10.2 gr A-1680) 999.6/907.8 fps
Maker 220 gr( 10.4 gr A-1680) 1066/977.2 fps
Factory:
Rem L300AAC4 220 gr 1144/1057 fps
Hornady Sub-X 190 gr 1117/1056 fps

Now with super-sonics the difference is more significant. A 16-inch barrel will push a light weight super sonic bullet quite a bit faster than a 8-10 inch barrel.

ETA: First velocity in from a 16-inch ballistic advantage 1:7 twist barrel. The second number is a 9-inch AAC 11:7 twist barrel.

kcofohio · Sep 5, 2019

Here's a link to some data a High Road member posted recently. It is best to view on a computer than a phone.

http://www.dayattherange.com/?page_id=3817

kcofohio · Sep 7, 2019

Wynder said:
I appreciate that insight! Great price on those... Let me know how they continue to work for you -- I'll have to pick some up and figure out a load for them.

Here are today's results.

kcofohio said:
I was able to get some chrony time today. I had loads of 11.0, 11.5, 12.0, & 12.5 gr. All using MBC 245 gr. Hi-Tek coated bullets. The COAL was 2.100".
I used CCI 400 primers and resized LC cases. All strings were 5 shots. The upper is a PSA 8 1/2" barrel, unsuppressed. At the end of the 5-shot strings, the bcg locked back each time.

11.0 gr.
Low-956
High-1012
Avg.-986
ES-56
SD-21

11.5 gr.
Low-1006
High-1034
Avg.-1026
ES-27
SD-11

12.0 gr.
Low-1050
High-1084
Avg.-1067
ES-33
SD-14

12.5 gr.
Low-1108
High-1138
Avg.-1123
ES-29
SD-13

Another great day to be at the range.

Edit: Temperature was 75' and mostly sunny.
Elevation, well the area use to be part of the Black Swamps near Lake Erie, so it can't be all that high.

reddog81 · Sep 8, 2019

I’ve just started reloading for the 300 BO and found it easy enough to get subsonic loads. The real test is to try and find an accurate and reliable subsonic load for your gun.

I went with a 16” barrel only so I could use a normal shoulder stock without the hassle of registering a short barrel rifle.

mcb · Sep 8, 2019

reddog81 said:
I’ve just started reloading for the 300 BO and found it easy enough to get subsonic loads. The real test is to try and find an accurate and reliable subsonic load for your gun.

I went with a 16” barrel only so I could use a normal shoulder stock without the hassle of registering a short barrel rifle.

Pistol brace is the answer your seek... At least until the ATF changes it's mind...

.300BLK Supplies and Thoughts

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Member

Similar threads