300 blackout

[4runnerman]

Hello all. First run for me with this caliber. I have trimmed 500-223 cases,annealed them. Getting ready to size, trim,chamfer and load. Using CCI400 primers, Accurate 5744 powder. At this point in time all I have is 168 gn bullets. Seems 110 to 125 gn is the primo weight to be in for accuracy. Any advice or help would be great.

 

[Sharkbite]

Check out 300blktalk.com. Lots of load data there.

You are correct...for supersonic ammo the 110-125gn bullets reign. Subsonics usually use 200+ grain pills

You dont mention the platform you will be shooting. 5744 will work fine in a bolt gun. If running an AR its all about gas port location and size.

I have loaded some 150gn supersonics. Only because the bullets were so cheap. 168's wont give you the speed the 110's will. The cartridge really is best at the two ends of the weight spectrum.

Get on the other forum and read...its a cool cartridge within its limits.

 

[4runnerman]

Thanks Shark. It's my bosses. I think he said it was the pistol version?. It's an AR, but man is that baby short. Has this stock on it with a velcro strap to velcro it to your arm right above the wrist.

 

[velillen]

I've shot plenty of the 147gr bullets and have had good accuracy. Get moa with them. I've used the 5744 since it was all I could find but I'm not to happy with it. Always up with unburned powder which obviously effects accuracy.

But yes generally you see the 110 for supers and 200 plus for subs. Though I've heard of guys using 175 smk for subs too

 

[4runnerman]

velillen- I heard 5744 was the go to powder?. From what I can did up under loads it sees 110 and 1680 are the best choices. 5744 was all I could find also

 

[Sharkbite]

If its an AR pistol, then its good to go for port location. Size is probably ok as well.

The issue may come up with an odd weight bullet and less then the ideal powder.

Pistol length gas systems are more forgiving then carbine length systems. I never had great luck with 5744 and 208gn subs, but it might work for supers.

Powders that work better for me
H110/W296
4227
A1680

 

[Mobuck]

I did a test load last week using H-110 and Hornady 190HPBT at barely super sonic. Using a 12X optic, I got a 3 shot cloverleaf out of my first group. That upset me and the rest were "slightly" bigger. I'll just say "pretty nice accuracy". I'm going to try Lil-Gun before loading more than just a few to play with.

 

[4runnerman]

Mobuck thats great shootig. I have had no luck with those powders around here. All I can find is 5744 for now. I heard 110 and 1680 are great powders for it.

Before I forget again-Case life?. With such a small shoulder these cases must be good for a lot of reloads. How many are you guys getting?.

 

[tcoz]

I shoot 147 and 150gr all day every day. MOA on a good day and 2 MOA on other days.

 

[psalm7]

Powder has been a problem for me with the .300 BO . Im getting alot of brass acumalated by buying the Remington green and white box 120 grain at Walmart and having fun shooting it and using the brass . Sofar the Remington brass has been stamped Barns .

 

[4runnerman]

psalm7- I just did the chop saw at Habor Freight and cut 2000-223 cases down.
To all First off I am a dedicated Bench shooter with a SCOPE. Had to get that out.
k made first run to the range today with NO Scope. I had 50 rounds with 168 Serria Match and 50 rounds with 125- Speer. Both shot very well. At 50 yards I managed to keep the rounds in a 2 inch group. For me and no scope that is unheard of. Sent some pics to the boss ( his gun). Told him-- With a scope this thing will probably shoot real nice. I must admit it was kinda fun to shoot that thing. I put that adjustable front and rear sight you get when you buy a SW MP15 22. Once I got it set at 50 yards it just kept putting them in a very nice group. I am tempted to take the scope off my 22-250 and head back tomorrow and see what it will do.

Question- While 50 yards is not that far, I did notice this
168 Serria- 16.7 gns A5744
125 Speer- 18.9 gns A5744
At 50 yards I had same POI on both loads, Taking into consideration open sights and me not being worth squat with open sights I would have thought a bigger difference then that.