6mm-223

[MarkCO]

Wow! Thanks for all the info. I want to stick with my standard AR mags since I cant get any new ones (maybe someday we will get our freedoms back). The 6.5 and 6.8 use different mags dont they?

If you are talking about the 6.5Grendel and the 6.8 SPC, yes, different bolts and different mags. The 6x45 is a pretty decent cartridge. It is actually one you can reasonably use as an all-around AR if you reload since the Nosler Varmageddon is about $165/1K.

If you want a 6.5 in the same vein as the 6x45, give me about a month and I will have my prototype up and running. Everything the same as the .223/5.56 except the barrel. Bullets are more coin, and heavier, but the ballistics are very promising.

[belizejet]

Looks like it is a lead time of at least 6 months just for a barrel. I guess I should order one and it will be a later project.

[belizejet]

MarkCO sounds good. Let me know how it works. Im looking for a cartridge with a little more umpf than the .223. Already have a 300BLK but I know there is a perfect cartridge out in the world for an AR that you can hunt with and is more efficient at longer ranges than a 300BLK. I am thinking 6 or 6.5 mm.

[MarkCO]

Sure will. Just FYI, my starting point is a 107 Sierra at 2650 from an 18" barrel. After that, I will try 95s, 123s and 130s. No plans to go heavier. There is not a lot of data, so I am working it all up in a pretty conservative manner.

[belizejet]

Didn't know that .243 projectiles got heavier than 115 grn.

[Hoser]

Didn't know that .243 projectiles got heavier than 115 grn.

David Tubb made a run of 117s. He put a plastic tip in the 115 Matchking (DTAC) until they kept blowing up on the way to the 800-1000 yard targets at the 2008-ish Rocky Mountain long range championship.

That is/was the heaviest 6mm that I know of.

[MarkCO]

Didn't know that .243 projectiles got heavier than 115 grn.

I am using 6.5 bullets.

[belizejet]

OK, another question. I am thinking of finally pulling the trigger on a 6x45 barrel in 18" but dont know what twist. 1:9 or 1:10? I plan on trying standard size .243 projectiles like 85grn plus or minus. not any heaver than 95grn or I would lose any advantage you gain over the 300BLK. I bought the dies already to start making brass and now I want to build the upper.

[SideShow Bob]

OK, here is a dumb ass I don't know crap question.

If the 6 and 5.56 (.223) both are 45mm in length and using the same bolt, what prevents one from pulling a Tard move like chambering a .223 or 5.56 and pulling the trigger in a 6X45 ?
I can see the oppisite of a 6x45 not fully chambering in a 5.56x45.

[AKA-Spook]

its called fire-forming.