300 ACC Blackout die question

[NWFLYJ]

I am going to cut my 223 brass down and I have an annealer. Question is do I go right from annealer to the dies? Also what dies do I need to purchase? Thanks Mark

[Artful]

You have several companies that make 300 Blackout Dies - I'm using Redding myself

[NWFLYJ]

No special die is needed to transform the cut 223 to 300?

[nhrifle]

300 AAC is easy. Just cut .223 case below the shoulder, run through the sizing die, and trim to length. Ready to load.

[StratsMan]

NWFLYJ, the shoulder on the 300 BO is so small that the sizing die will shape the brass with very little effort... as stated earlier, remove shoulder from the 223 (try to get close to the correct length), lube the brass and run it through your sizing die. Trim to length, and double-check that it fits your chamber...

RE: video in the previous link...
What that guy failed to mention is that you can't get a trim die for 300 BO from Dillon, so you have to find another trim die maker. I can't remember the name of the company that makes that die, but it's out there... I have used that trim die, and you can use it for sizing your brass, as he shows in the video, but you don't get an expander die to do the neck size. Also, the toolhead in his 650 is not a standard Dillon part. That toolhead has had a lot of material machined off the top, or it's a new part that is thinner by design. Why?? Because the 300 BO case length is too short to use a standard toolhead, so you have to use a thinner head. Last, the Dillon trimmer was never intended to cut that much material off of a case... Plan on going through your cutters quickly with that method

[thehouseproduct]

You can get 300 whisper trim dies from CH. use an extended shell holder and mount it on a single stage. Works great. You don't need to expand case mouths afterward for jacketed billets but I do for cast.

[NWFLYJ]

Thanks for all the input. I picked up a harbor freight mini chop saw and a 223 jig for holding the brass.

[GRUMPA]

Thanks for all the input. I picked up a harbor freight mini chop saw and a 223 jig for holding the brass.

I do mine the same way, best if you tumble them to remove the burrs that you create when using the HB saw. If you don't those little pieces of brass will embed themselves in the die especially the neck area and your going to be blessed with grooves on the neck.

When I anneal mine it's the last thing I do, if I did that first then clean it, it would remove all the annealing marks and they wouldn't think it was annealed.

[NWFLYJ]

Great tip, thanks Grumpa