[Catfish]

I've been trying for a while to get these to run using published load data with poor results. I called Lucky13 for advice and was told "slow them down to around 1650 fps". The following are results from my first successfull range trip with these bullets - I believe I'll be buying some more!

All shots at 25 yds across a CE Prochrono. Most groups were about 2" not counting flyers and paying more attention to missing the chrono than hitting the target. Previous attempts using published data gave me 8"+ groups at this distance. All of these fed, fired and cycled the action with no burps.

Gun: 300BLK DSG/Seekins 10.5" "Black Friday" upper on an Anderson lower.
Bullet: Lucky 13 124gn coated 0.309 "Zombie Green"
Powder: H110 from 13.0 to 15.0 gn
OAL: 1.875" (0.04" off the lands)

13.0 gn - 1509 fps
13.5 gn - 1474 fps
14.0 gn - 1602 fps
14.5 gn - 1624 fps
15.0 gn - 1721 fps

results:
I can't explain the dip in velocity @ 13.5 gns but it's probably instrument error.
Could probaly slow them down some more - maybe get them subsonic with a can. That's another project.
15.0 gns is still a little hot for these as the group opened up an inch or two.

I'm going to run with this for a plinking load in this upper:
300BLK 124gn L13 Zombie Green, 14.5 gn H110, OAL 1.875", CCI#400.

 

[Catfish]

Because this thread is useless without pics:

 

[Wahoo95]

Is your handguard rock solid in terms of movement? Even a small amount of movement will affect grouping with the optic mounted to it.

 

[Catfish]

No the hand guard is not loose, it's rock solid. And jacketed bullets group nice and tight like you'd expect them to at 3-4x the price of these.

 

[lucky13bullets]

continue slowing them down.

you will find a point just before they stop cycling that you can hold a 2" group at 100 yards.

yo may need to use a powder that creates more gas, i had the best luck with them around 1550 fps with 4227 powder

cast bullets in a rifle is like robbing from peter to pay paul... you need to spend more money up front in powder and trial and error to develop a load that works, once you get there it gets really cheap. these work like a champ for plinking, but like i said before, they aren't match bullets... 2" groups are about the best i can get with them in a 10.5" aero precision SBR