Sharing my tips on how to ID your 300 BO so you don't accidently send a 30 cal bullet down a 22 cal barrel.

1) My 300 BO rifles have a RED charging handle.

2) 300 BO mags have a Ghost baseplate to allow quick ID of the mags. I use the Ghost MOAB on my PMAGS. A Sharpie Red OIL based marker is used on the dimples for color ID. A regular Sharpie doesn't work as well as the Oil base.The baseplate ensures that the PMAG "looks and feels" different. MOAB also is made for Lancer mags.

Link to Ghost: https://ghostinc.com/the-rifle/ar-magazines/

All my 300 blk weapons have FDE furniture. The ARs use Magpul mags.
All my 556 ARs are black and use Lancer mags.

Only exception to this rule is my 556 Tavor, which is FDE, but it also uses Lancer mags.

quote:

Originally posted by AllenInWV:
All my 300 blk weapons have FDE furniture. The ARs use Magpul mags.
All my 556 ARs are black and use Lancer mags.

Only exception to this rule is my 556 Tavor, which is FDE, but it also uses Lancer mags.

No 300 in the stable here, but this was my first thought. Plans are still to do a 300 pistol in the future.
Color-coordinate per caliber.

My 5.56 has all black stuff, 20rd, 30rd, 40rd.

My 300s all have Lancer 20 FDE baseplate round mags or FDE 30rd Hexmags.

I owned a .300 for a couple years a while back. Never ran into any trouble, even with no identifying marks. I am fixing to put together a .300 again, and I don't intend to do anything special this time either. I respect the idea though.

quote:

Originally posted by Chowser:
My 5.56 has all black stuff, 20rd, 30rd, 40rd.

My 300s all have Lancer 20 FDE baseplate round mags or FDE 30rd Hexmags.

Same here

When my .300BO surefire suppressor clears I'm going to be more serious about this issue. I'm thinking to paint the whole gun purple, or maybe red.

I tell them apart by location. One is at the range, the others are home.

My 300 upper and my 5.56 uppers have very different roles, so not only do the look different it's highly unlikely I would ever bring them to the range at the same time.

I swap barrels on a AR pistol between the two calibers.(use the dolos pantheon quick barrel removal system)
My 300 has a 10” barrel where my 5.56 pistol is shorter
The 300 barrel is obviously thicker.
Loaded mags are segregated by color-300BO only go in black pmags. 556 goes in USGI aluminum mags

My 300 gun is an MCX and not an AR.

That said, I use either Lancer or Magpul dedicated 300 BLK mags, so the Lancers have different floorplates and I've colored in the 300 marking on the Magpuls. Will get around to an AR one of these days.

That top round isn't presenting well. How has .300 been, in those mags? I intend to do the same thing before long.

quote:

Originally posted by cas:
I tell them apart by location. One is at the range, the others are home.

This is something I’ve stressed before: One of the many (>> “the four”) firearms safety rules is don’t create or allow a situation in which it is even possible to load and fire the wrong ammunition in a gun. Safest is to have one kind only where we’re shooting. If we must take two or more different types to the range, make sure everything is segregated in the vehicle, and take only one type to the firing line at a time.

Having more than one type available at the same time that can be loaded and fired leads to things like this:




Firing the wrong handgun cartridge in a pistol usually leads to nothing more than embarrassment, but sometimes the wrong ammunition can be catastrophic.

But to answer the original question, my 300 Blackout magazines are all clearly labeled.

quote:

Originally posted by KSGM:
That top round isn't presenting well. How has .300 been, in those mags? I intend to do the same thing before long.

Good eye! I actually dropped the mag right before the photo and it unseated the top round. The 300 blackout rounds work great with the 556 mags. I haven't had any issues with the san platforms.

The Swiss tested the 300 blackout round fired through a 556 barrel. If I recall correctly this was a Sig 553 lb with a barrel length of 13.66 inches. A shorter length barrel and that round might have cleared?

no .300 in the house either,

however I do have a 6x45mm rifle,

it's in a standard A1 ish config with A2 handguards,

I painted a red band around the front of the handguards, (Commonwealth country practice) to help denote the difference

I use PMAGs in the 5.56 AR's and Lancers in the Rattler (it came with a Lancer so I bought extras). Technically the Lancers are 5.56 mags, which are fine for supersonic 300 BLK. For Subsonic I might get the 300 BLK specific Lancers with the FDE baseplates. But without ammo I'm not shooting it so...

I have an ejection cover laser etched with 300 Blackout on the upper. For the mags that I use, I have colored elastic bands labeled 300 Blackout around the base of the mag.

m3 pmags with sand floorplates dyed red.

I have .300blk Pmags and use similar bands that gw3971 uses.