I am completely new to reloading and have been acquiring all of the equipment and supplies for a while and have been doing as much learning as I can while I waited to get everything together.

I decided to start reloading the 300 Blackout round since it is hard to find and not very cheap and I like the caliber.

I spent yesterday working up some loads to try and find one that works well in my rifle. Unfortunately the round I bought a lot of, the Sierra 125gr OTM .308, does dot have any loading data out their on any of the powder companies websites and I have had a very hard time trying to figure out a starting point and cartridge OAL. The 300 Blackout forum is not very helpful, although there is good information; it is just spread out all over the place and not really organized.

Well I decided to make my OAL to 2.210 since when I did some more reading that would put the ogive of the bullet at the rib in the magazine. Today I went and tested 5 worked up loads and need to work up some more until I find the right fit for me as there were no signs of pressure at the top load I tested today.

Noveske 300BLK
Pistol length gas system
10", 1:7
MagPul PMAG, 30RD
125 gr Sierra OTM
Hodgdon Lil'Gun 15.7gr, 16.0gr, 16.3gr, 16.6gr, 16.9gr
LC 5.56, reformed to 300BLK
CCI 400 Small Rifle
2.210" OAL
1/2 turn light crimp Lee FCD
No Chrono yet
Zero Issues on any of the loads. All feed, fire, and eject fine.
Bolt held open on last round.
I fired 5 rounds suppressed and 5 rounds unsuppressed for each load.
My suppressor is the AAC 762-SDN-6 and with factory ammo there is not much of a shift in POI with the suppressor on or off but I did have POI with each load today.


All shots fired at an indoor range at 50 yards.


This is when I fired some factory Remington 115gr ammo and the way I want my reloads to be!


The 5 rounds on the left are what I made from 5.56 brass and the last round on the right is factory ammo.

This message has been edited. Last edited by: StorminNormin,

Very cool. How do you make the cases from 5.56 without splitting the neck?

Well done! Pretty ambitious for a first time reloader; semiauto & semi wlidcat round. Are you making brass or using purchased formed cases? I think one of my next projects is going to be a 300BO upper. I am looking for a good semiauto lead bullet shooter.

quote:

Originally posted by flesheatingvirus:
Very cool. How do you make the cases from 5.56 without splitting the neck?

In the 300BO, you aren't really necking up as you cut off the 223 neck, so you are really forming to 30cal. I thing the 300BO would be great with 150-160gr hard cast lead bullets going 1500-1600fps.

Shooting is looking good.

quote:

Originally posted by flesheatingvirus:
Very cool. How do you make the cases from 5.56 without splitting the neck?

A picture is worth 1000 words.

quote:

Originally posted by fredj338:

quote:

Originally posted by flesheatingvirus:
Very cool. How do you make the cases from 5.56 without splitting the neck?

In the 300BO, you aren't really necking up as you cut off the 223 neck, so you are really forming to 30cal. I thing the 300BO would be great with 150-160gr hard cast lead bullets going 1500-1600fps.

Yes, to use 5.56 brass for a .308 round you must cut off the neck of the brass, reform the cartridge in a sizing die to make a new neck for the 300 BLK round, and then trim it to the proper length.

So far all of the rounds I have reloaded are from 5.56 brass I have reformed. I did purchase some Hornady 300 BLK brass but I have not used it yet as I have plenty of 5.56 to convert. It does take more time, but I find it fun.

The Hodgdon website is replete with information for the 300 AAC Blackout. I would use the data for the 125gr Nosler Boat tail.

The load you listed is at the low end.

This message has been edited. Last edited by: NikonUser,

quote:

Originally posted by 45 Cal:
Shooting is looking good.

Thanks 45 Cal! These reloads are with the brass you helped me with

My powder charge is low and I am sure I will get better accuracy as I continue to work up this load.

quote:

Originally posted by NikonUser:
The Hodgdon website is repletr with information for the 300 AAC Blackout. I would use the data for the 125gr Nosler Boat tail.

The load you listed is at the low end.

The bullet has been out for a while and I don't know why they haven't updated it with this specific bullet when it was supposedly even made for the 300 BLK.

Since I am new, I wanted to be better safe than sorry.

quote:

Originally posted by AndyM1911:

quote:

Originally posted by flesheatingvirus:
Very cool. How do you make the cases from 5.56 without splitting the neck?

A picture is worth 1000 words.

That is a great pic; I am going to steal it!

quote:

Originally posted by StorminNormin:
[The bullet has been out for a while and I don't know why they haven't updated it with this specific bullet when it was supposedly even made for the 300 BLK.

Since I am new, I wanted to be better safe than sorry.

You're doing fine. You're lucky that Hodgdon has so much information for such an obscure round in the first place and I would just use the data for the 125gr Nosler BT they have listed.

I see you go to Red's I've been there several times myself. I'm also a "member" at Eagle's Peak, so when I got to Austin, I have a couple of places to shoot.

Interesting. I didn't realize it was that much shorter than a 223 case.

quote:

Originally posted by NikonUser:
I see you go to Red's I've been there several times myself. I'm also a "member" at Eagle's Peak, so when I got to Austin, I have a couple of places to shoot.

Yeah I used to go to Eagle's Peak long ago when it was when of the few ranges around, but now days I don't really like that range very much, but I am still a member. Reds is within a few miles of my house. Another good range is in Lockhart called the Lone Star Gun Range; I like them the best but they are about 45 minutes from my house.

quote:

Originally posted by flesheatingvirus:
Interesting. I didn't realize it was that much shorter than a 223 case.

Yup but it ends up being close to the same length as a 5.56 round so all that has to be changed in an AR-15 is the barrel to now shoot a .30 cal round out of an AR.

quote:

Originally posted by StorminNormin:

quote:

Originally posted by 45 Cal:
Shooting is looking good.

Thanks 45 Cal! These reloads are with the brass you helped me with

My powder charge is low and I am sure I will get better accuracy as I continue to work up this load.

Glad it worked,what bullet weight's have you tried?
When I was researching for something in use for sub guns they recommended heavy pills.
Let me know if you need some heavies.

quote:

Originally posted by StorminNormin:

quote:

Originally posted by flesheatingvirus:
Interesting. I didn't realize it was that much shorter than a 223 case.

Yup but it ends up being close to the same length as a 5.56 round so all that has to be changed in an AR-15 is the barrel to now shoot a .30 cal round out of an AR.

I got my lower built last weekend on my AR I'm going to use for 300BLK. Having some trouble deciding what to do about the upper. Complete upper about 4 to 6 months out. Parts to build an upper scarce as hell.

Been forming brass in my spare time. It does take some time. Lots of steps. Did you use the case and ammo gage available from the guy on 300blacktalk?

quote:

Originally posted by StorminNormin:
Yeah I used to go to Eagle's Peak long ago when it was when of the few ranges around, but now days I don't really like that range very much, but I am still a member. Reds is within a few miles of my house. Another good range is in Lockhart called the Lone Star Gun Range; I like them the best but they are about 45 minutes from my house.

Thanks for the info. Any excuse to go to Lockhart is welcome; there is some awesome BBQ there. 45 minutes isn't too bad. That's how long it takes me to get to Bayou with its 1000 yard range. I have several 100-200 yard ranges within 20-30 minutes from here and there are two indoor ranges about 4 minutes from the house.

I used to compete at Camp Swift near Bastrop but this past year they closed it down to civilians.

quote:

Originally posted by 45 Cal:
Glad it worked,what bullet weight's have you tried?
When I was researching for something in use for sub guns they recommended heavy pills.
Let me know if you need some heavies.

So far I have just used a 125gr and doing supersonic. I have a few other 110gr supersonic rounds I want to try and then I am going to get a 220gr to try subsonic. The powder I need for subsonic has been harder to find; I have 1lb of it so far.

quote:

Originally posted by sandman76:
Did you use the case and ammo gage available from the guy on 300blacktalk?

I use the L.E. Wilson Case Length and Headspace Gage

Which gage are you referring to?