I recently built a SBR 300blk using a BA 8.3 barrel. Yesterday I loaded my first 20 rounds of ammo for it using once fired factory 300blk brass that was shot through my gun. I also have everything to cut and form my own 300blk brass from 223 brass at some point..

The load did really well at 50yds and 100yds. I was only using a 1-3 power Weaver scope, so at 100 yds the groups opened up. When shooting at the 100yd target I was just aiming at the center and pulling the trigger. The groups would be smaller with a higher power scope, but I am satisfied with the groupings for such a low power optic.

This gun is zeroed for 150gr ammo and hits dead center with it. The 110gr and 120gr ammo hits slightly high and right. Both 50yd targets are 5 shots and 10 on the 100 target.

The load was:

Hornady 110 gr VMAX
19.0gr IMR 4227
Win SRP
Fed Brass
OAL 2.068

I like those 1-3x Weaver Classic scopes. Have 3 of them, 2 on carbines and one on a 300blk pistol with 8.5" barrel.
No short barreled rifles for us folk in CA unfortunately...

Looks good.  What make HG did you use length? Thx

Thanks. The rail is an Aero Precision Atlas One rail.

The 300BLK is definitely a fun little cartridge to load and accurate too.

I've had great success with 100-120gr bullets, The 100gr Lapua HP with 19gr IMR4227 will shred one hole at 100 yards with most 300BLK rifles.

The Hornady Z-Max line of bullets in several different diameters are excellent bullets. 110gr Z-Max with 19.8gr Alliant 300-MP has been a great load for many 300BLK rifles.

IMR4227 is a really good powder for the 300BLK and has provided excellent results for many different loads.