300BO

Dec 8, 2011
10
26
13
43
Tampa, FL
#1
Guys hoping to get some load data from the folks that load 300BO. I saw a few threads for subsonic loads but can't seem to find any for supers (apologies if it exists).
I'm looking to load primarily for hunting (pigs mainly) and to play with accuracy (for fun). I've been running 110gr Barnes Vor-TX ammo for hunting and it seems to do well but I was hoping to see what other folks are loading with.
Primary rifle is a 12.5" Proof barrel (pistol length gas system with a 1:9 twist) in a Hodge Defense upper/lower with a Surefire SPS300 suppressor.
Other rifle is a 16" Rem 700 AAC-SD rifle in a Manners T4 side-folder with a Surefire SPS300.
Thanks so much and I'm new and in learning mode so go easy on me :)
 

padom

SuperMod
Staff member
Mar 13, 2013
6,979
904
113
Southeastern, Pennsylvania
#2
I run both 125 SMK and 125 TMK out of my 10.5" Ultramatch with H110. Both are extremely accurate with the 125 TMK being slightly more accurate but expand better. Did some unscientific testing with denim and wet phone books and the 125 SMK slightly bowed like a banana. Didnt expand or anything. The 125 TMK expanded like a 9mm Federal HST beautifully. Im getting just over 2100fps with the below 125 TMK/ 18.6gr H110 load out of my 10.5" barrel and have no problems consistently hitting steel out to 500yds.


 
Dec 8, 2011
10
26
13
43
Tampa, FL
#3
I run both 125 SMK and 125 TMK out of my 10.5" Ultramatch with H110. Both are extremely accurate with the 125 TMK being slightly more accurate but expand better. Did some unscientific testing with denim and wet phone books and the 125 SMK slightly bowed like a banana. Didnt expand or anything. The 125 TMK expanded like a 9mm Federal HST beautifully. Im getting just over 2100fps with the below 125 TMK/ 18.6gr H110 load out of my 10.5" barrel and have no problems consistently hitting steel out to 500yds.


Stupid question but do I need bullets specific to 300BO? I've seen some bullets labeled as "Short Case" which I know is for 300BO but others I have not so it had me a bit confused.
 

Onyx Z

New Hide Member
Sep 27, 2018
45
25
18
#5
300BLK specific bullets are typically flat base bullets. Generally speaking, flat base bullets are inherently more accurate, but for 300BLK, they don't give up case the volume for the boat tail. These "short case" bullets you speak of most likely have a flat base. Any 308 bullet will work though. Obviously lighter for supers and heavier for subs.

YMMV, but the Barnes solid copper bullets typically produces more copper fouling than a jacketed bullet, so you may need to remove the copper from the barrel more often. Typical jacketed bullets have gilding metal jackets (95% copper/5% zinc) to prevent/reduce copper fouling. I have some CFEBLK, but haven't tested it yet. Theoretically, it should reduce the copper fouling.

I know you are primarily looking for supersonic loads, but, your 1:9 twist barrel may not stabilize any of the heavier/longer bullets.
 
Likes: 504ranger
Dec 8, 2011
10
26
13
43
Tampa, FL
#6
300BLK specific bullets are typically flat base bullets. Generally speaking, flat base bullets are inherently more accurate, but for 300BLK, they don't give up case the volume for the boat tail. These "short case" bullets you speak of most likely have a flat base. Any 308 bullet will work though. Obviously lighter for supers and heavier for subs.

YMMV, but the Barnes solid copper bullets typically produces more copper fouling than a jacketed bullet, so you may need to remove the copper from the barrel more often. Typical jacketed bullets have gilding metal jackets (95% copper/5% zinc) to prevent/reduce copper fouling. I have some CFEBLK, but haven't tested it yet. Theoretically, it should reduce the copper fouling.

I know you are primarily looking for supersonic loads, but, your 1:9 twist barrel may not stabilize any of the heavier/longer bullets.
Perfect and thanks so much for the help ya'll have provided. Definitely feel better about buying bullets now after learning.
 

Snuby642

Sergeant of the Hide
Feb 11, 2017
1,009
536
113
#7
Both my 300blk barrels are 1/7 twist, 16 and 10.5 inch.
They will both stabilize 200-220gr bullets "subs".

I would check the 1/9 short barrel without the suppressor in load development
to ensure they stabilize befor using the can.

My pet load is 12.1 cfeblk 220fbrn 2.1 coal slight crimp 1050fps in 16 inch barrel.
This is a 100 yd load and is consistant.

I didn't buy the 300 blk to shoot supers but since I have my sub load sorted out
I may try some loads like @padom suggests.

The cfeblk is working well for us.
 
Likes: 504ranger