300 blk subsonic clean burning powder?

Coletta

Sergeant
Full Member
Minuteman
Oct 27, 2011
280
2
Memphis, TN
I initially bought some hornady factory subsonic 300 whisper ammo loaded with 208 amax. I got a good deal on the stuff, and to my surprise it is very accurate. I am almost done with all the factory ammo, and i will be reloading the brass. I would try to copy the factory stuff, but it burns extremly dirty. 20-30 shots will leave the barrel filthy and groups get nasty (some unburned powder and tons of carbon). Is anyone else having similar issues? If not, what is burning clean for you? I will continue using 208 amax bullets.

FYI, I have disected one of the factory rounds. It is a very fine spherical powder. I think it was around 10-11gr.

Rifle specs:
16.5" 1:8 bolt rifle
 
Re: 300 blk subsonic clean burning powder?

I imagine factory ammo is set up to cycle ARs. Since you have a bolt gun you could use a little faster powder. Faster burning should equal cleaner. I use American select with 110 grain jhps and aa1680 with 208 amaxs. Haven't noticed the 1680 being dirty or not. The 208s are louder than 110s. Due to slower powder equals higher muzzle pressure. Good luck. There is quite a bit of data out there but most is for the ARs.
 
Re: 300 blk subsonic clean burning powder?

Thanks Gents,
How much 1680 are you using with the 208's?

I knew a lot of folks were using 1680, but never heard about how clean it burns til now.
 
Re: 300 blk subsonic clean burning powder?

I'll have to check my notes and get back to you. I think it is somewhere in the 10.5 grain range for a muzzle velocity of about 1050. But let me double-check.
 
Re: 300 blk subsonic clean burning powder?

Just checked. The load is 10.5 aa1680. I was shooting 10.8 then dropped it 0.3 grains. 10.8 was subsonic but I was getting more noise than I wanted so decided to try 10.5.

Shooting a trued 700 with a shilen 8 twist 16.25 inch barrel.
 
Re: 300 blk subsonic clean burning powder?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BLK7</div><div class="ubbcode-body">Just checked. The load is 10.5 aa1680. I was shooting 10.8 then dropped it 0.3 grains. 10.8 was subsonic but I was getting more noise than I wanted so decided to try 10.5.

Shooting a trued 700 with a shilen 8 twist 16.25 inch barrel. </div></div>

I am using a shilen barrel too. My was built on a howa action.
Just picked up some 1680. I will share some results with ya'll later.
 
Re: 300 blk subsonic clean burning powder?

Also agree on the Vhtv. n-110

I have both AR & Bolt at the present time .& have owned 4 total of this cartridge in Bolt & AR over the last few years.
Now just run the n-110 for both AR & Boltaction . It's clean & I get acceptable accuracy from both using it .
.
 
Re: 300 blk subsonic clean burning powder?

I will try some n110 if I am not satisfied with the 1680. Too many 1# powder jugs in the cabinet right now. I also got some Blc2 for some 6.5 grendel work ups yesterday, and hit my spending limit.
 
Re: 300 blk subsonic clean burning powder?

N-110, you will like it .
your initial question was asking for cleaner power . I use a lot of N-320 also for pistol & I don't think you get much clearer burn than the Vitv. powders .
.
 
Re: 300 blk subsonic clean burning powder?

VVN110 is one of the best subsonic powders for 300 BLK, but may or may not cycle your AR15. It worked great in my 10" barrel with a selectable gas block. AA1680 is very dirty. It's what is used in the factory ammo that you are having a problem with. I tried H4198 and it requires about the same charge weight as 1680 to achieve the correct velocity. I only shot <20 rounds, so I can't say whether it's cleaner or not, but I really doubt it's any dirtier than 1680. Give it a try if you have any.