300 Blackout Load Data
I am starting this thread to post my results of loads I try good or bad for the 300 BLK. and everyone is welcome and encouraged to add load data from there 300 Blackout load results.
My 300 Blackout is built on a Spikes Forged Upper and Lower receiver with a RRA Chrome BCG and Wilson Combat 16" SS Match Grade Barrel.
First I wanted to try some 110 Hornady SP Bullets. Wanted a good cheap round to shoot and even hunt with. I wanted to hopefully get 2400 FPS out of it with minimal signs of pressure and good accuracy is a must. First i just wanted to find what loads would keep me in between 2300 and 2400 FPS no accuracy test until i find the load range I have to work with. I will be doing this with almost every .308 bullet available from 110 to 165 grains and will post results on this page as I go.
This took place on 8/4/11 at 80F and 60% Humidity
Hogdon H110 Powder loaded in PMC .223 brass sized by Lee 300 Blackout dies over Tula NCSR-223 primers. Hornady 110 SP bullets OAL 2.00
19 Grains. No pressure signs but a little slow rifle did cycle fine LRHO
19.5 Grains. In the fps range I wanted no pressure signs rifle ran well
20 Grains. In the middle of fps I wanted rifle ran fine no pressure signs
20.5 Grains. Started showing signs not bad but 2400fps
I tried 21.5 grains but only shot one round very flat primmer it ran 2454 fps but I will pull the rest apart to hot for me :tdown:. I will load up 6 round each with 19.8, 20, 20.2, 20.5 grains of H110 they should all be above 2300 fps and see witch one holds the tightest groups.
WARNING! SOME LOADS IN THIS THREAD MAY EXCEED RECOMMENDED CHAMBER PRESSURE FOR THE 300 BLACKOUT. DESPITE MY BRASS AND RIFLE NOT SHOWING ANY SIGNS OF EXTREME PRESSURE, YOUR RESULTS MAY VARY. IF YOU CHOOSE TO REPRODUCE THESE LOADS, DO SO AT YOUR OWN RISK
Last edited by Edward78; 08-04-11 at 12:33.
I found a post on silencertalk touting Unique as a good subsonic load. I ladder-stepped a load from 5.4 to 5.8 gr with 220 gr SMKs and Rem 7-1/2 primers. COL was 2.20".
Results were terrible. Velocity ranged from low 700s to 875 fps or so, even within the same charge weights. Groups were about 2" at 50 yds. for any given load. Obviously too much space in the case to have consistent powder ignition.
N110 is my next experiment, though the closest source is an hour away so it might be a while before I make it up there.
ETA - I also chronyd the Hornady 110 gr VMAX Whisper load and it was puulling 2450 fps out of my 16" barrel. Plenty potent for hogs or deer.
Last edited by Polymerhead; 08-04-11 at 18:22.
I have got the best accuracy and lowest SD/ES with Vhit N-110.
Not the quietest as N-110 is on the slow side, but if the accuracy is there I am ok with it.
With an AR I use H-110 or N-110 as I wont be shooting it past 150 yards or so. The H-110 is a bit dirtier with or without a can.
Subsonic loads with H110 or N110 are not good for a semi 300 BLK.
That is why I have an M-16 RR.
Originally Posted by Todd.K
Why are subs not good with H110 or N110?
Those powders don't generate enough gas pressure to cycle the action within Colt M4 specs for cyclic rate. This also applies to semi autos as cyclic rate and bolt velocity are related.
You can make those powders cycle by using an oversized gas port, but then you can't shoot supersonic ammo without exceeding M4 specs for the upper range of cyclic rate.
The solution is to build guns like AAC and Noveske, and use subsonic powders, like A1680 - or factory Remington subsonic ammo, which can cycle the action with a normal sized gas port.
So is AA-1680 the best powder to use for Subsonic loads I do plan to work up some sub loads to because a Can for my Blackout is on my to buy list in the future.
Have you had any trouble with the magazines?
I think A1680 is the best powder for subsonic from an AR if the primary goal is reliable function. RE-7 can work also but the charges are rather compressed.
Last edited by rsilvers; 08-07-11 at 07:58.
I am going o pick up some 1680 but good to know the RE-7 can also work I have that already I use it for my 6.8. How much RE-7 do I use to keep it in the subsonic range.
Originally Posted by rsilvers