300 blk 180 grain bullet loads?

I dont see why not. I run a 176 grain Lehigh Projectile and a 200 grain Makers at subsonic speeds, using H110 and Lil Gun.

I’ve used cfe blk with 190 subx bullets. I want to say I was using around 10 grains of powder but I’d have to check it’s been awhile since I loaded any 300 blk

Are you specifically asking for a subsonic load? That weight would not be subsonic in my rifle with 12" barrel. Shoots fine, just a little loud.

I’ve dabbled a little with 180’s in blackout. For blackout I pretty much only use enforcer, which with 13.5 grains of enforcer would do what you need. 180 is just a bad weight for me in the blackout, for hunting the 110 vmax is devastating inside 150 yards and holds together well with near perfect expansion, just because of the price I use 125 tnt’s for range use, the 180 is in that middle ground as to heavy for decent velocity and will have little to no expansion and to much drop and lighter than ideal for subs.

Playing around on GRT looks like you won't be able to keep it sub with either powder even in a 10.5. It also pitches a low burn rate error, and with 65% case fill, I'd believe it.

A1680 10-10.5gr in that length barrel probably. I’m subsonic with 190 gr and 11.5gr A1680 out of an 8” barrel.


7/23/22
94F 47% 30.01 in

A1680 190 Sub-X
Starline brass new
GM205M
COL 1.3580
BTO 1.635
11.2 974, 968, 1016, 984, 963
1028, 965 SD 26.1
11.3 1004, 984, 1005, 1039, 983 SD 22.6
11.5 1048, 1014, 1056, 1005, 1016 SD 26.1
11.7 1082, 1043, 1042, 1040, 1038 SD 18.5
12.0 1119, 1101, 1090, 1057, 1079 SD 23.2

Thanks, very informative.

It can be tough to get light bullets subsonic in the 300blk AND run a gas gun, which it sounds like you're going for.

180g or so bullets can normally do just fine in my experience, with a little experimenting. I have a 300blk that will run with the 180 sierra round nose and cfeblk and ive seen a few others do the same. I wanna say mine was about 1080fps. Gun is typical except added adjustable gas.

Using faster powders and going lighter for less noise often takes a bit of luck, and or some changes to the gun since you'll likely be using a non typical powder.

Oversized gas port with adjustable block, or maybe even playing with a shorter gas system, lighter carrier parts, lighter spring buffer etc can all help a lot, but its probably
not worth it in most cases.... unless you're just wanting weird lol.

Heck, you can run the little 100 or 90g short jackets, xtps and tiny cast subsonic and VERY quiet if you don't mind cycling the bolt manually.

Cfe blk or 1680 are probably where I'd look... they really help with function. Noisy, but run down to super low speeds with jacketed and cast stuff. I had a 6 or so inch 300blk running 250 cast ridiculously slow and still getting slide lock on empty.