Builder Armory

// Non-NFA Other · 300 BLK

GF-300CRB

300 Blackout /

GF-300CRB
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by G

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// Loadout

Equipment

SlotProduct
UpperMCX-SPEAR LT 9" UPPER AR CONVERSION KIT 300BLK-BLACK
Lower Parts KirFortis Enhanced Lower Parts Kit - AR15 - Minus FCU & Trigger Guard
GripFortis Manufacturing Torque Carbon Fiber Pistol Grip
TriggerRise Armament Rave 140 AR-15 Trigger - Flat Bow - Anti-Walk Pins
StockINDIVIDUAL STOCK/BRACE EXTENSIONS 8.5"
LowerLicense GEN II AR15 Lower Receiver - Carbon Fiber
RiserAT3 .83" 3 Slot Riser
Muzzle DeviceKVP 3.25″ Magnum Linear Comp
Pistol BraceTailhook MOD 1C – Black
Cheek RiserXENO CHEEK RISERS
LightPROTAC® RAIL MOUNT HL-X LONG GUN LIGHT
OpticHolosun ARO EVO SPR - Red Dot
Iron SightsCombat Rifle Offset Sight Set

// Range Log

Training Sessions

2026-10-01TrainingNo Malfunctions

This session was specifically to cite in my offset iron sights, FTF once, pretty sure its becuse i shoot unsuppressed subs and there is not enough gas to cycle strongly.

20
rounds
200 gr
2026-09-29TrainingFailure to Feed

Running New lancer magazines with Magtech 205gr subs. High Gas setting, re-zeroing the firearm due to an Optic change. I changed from the Holosun ARO EVO to the ARO EVO SPR. Gun is now Zerod at 25 yds. 1 failure to feed. Not sure if this was. magazine driven or what.

70
rounds
205 gr
2026-08-11TrainingNo Malfunctions

Still very accurate at 15 yards. As accurate as I need. Subsonics feel like air and are so quiet. I noticed the subs show about 2" lower at 15 yards than the subs.

60
rounds
208 gr
2026-08-11TrainingFailure to Eject

Not sure what happened but had a failure to eject. Other than that she shot great. 124 feels much nicer to shoot than the 147. I need to find some low grain supers.

60
rounds
125 gr
2026-07-26TrainingNo Malfunctions

I shot the following ammo today. The subsonics are very quiet, even unsuppressed. I had one failure to eject in the lowest gas setting. I increased the grass to the high setting and it ran smooth and seemleasly Winchester Ammunition, Super Suppressed, 300 Blackout, 200 Grain, Open Tip, 20 Rounds Hornady Frontier 300 Blackout, 125 Gr FMJ, 40 Rounds SELLIER & BELLOT 300 BLACKOUT, 200GR, SUBSONIC, 11 Rounds Sellier & Bellot 300 Blackout, 147GR FMJ, 20 Rounds The supersonic rounds had quite a bit of punch as expected. They were much louder but still not extremely concussive like the 556 round. I really enjoyed shooting the subsonic rounds, I'm going to try some defense subsonic rounds this week and decide on one to keep by the bedside. I'll be shooting this gun with subsonic moving forward unless outdoors. The smoothest shooting was the s&b 200 grain subsonic, I zeroed in at 15 yd and it was relatively accurate. My spreads were roughly 1.5 to 2 in.

91
rounds
Multiple
2026-07-19ShakedownNo Malfunctions

Gun shot phenominally, took 3 rounds to zero perfectly with the holosun aro evo. Zero's at 10 yards. This will be a CQB rifle used for home invasion so I dont need anything more thatn 10 yards. Recoil felt good. Since this is a new build I didnt do any multi shot testing. The sound was good considering. This gun is way less concussive than my 12.5 .556 AR. Sound more like a ported 9mm than a .556. Overall happy with the build. Also zerod the lazer on the flashlight to 10 yards. Will shoot more when in Charlotte next week.

30
rounds
147 gr

// Target

Shots: 12Extreme spread: 14.09"