What is a good set of dies for the 300 blkout

Lee

That nice you have all the dummy rounds marked for different bullets to besides the OAL.

Hornady over Lee.

I used my Hornady dies for all of my converted 300 Blackout brass.  The elliptical expander makes it easy (after annealing the parent case).

Before I bought the Hornady dies, I read everything I could find about different dies.  Lots of people noted that they had trouble converting brass with the Lee dies.

Nothing against Lee for most things, but I recommend spending a little bit more for the Hornady dies.

That’s what I decided on and ordered was the Hornady.
Thanks guys for the info.

OOPS, wrong thread.

Inside neck reaming is best done  while the neck is held in a die.  But no longer available/made.  

For accuracy,  inside ream, but leave enough case wall thickness to outside neck turn as the last step.

For plinking, doesn't much matter.  Reamers .  https://www.midsouthshooterssupply.com/dept/reloading/case-prep/case-neck-prep/neck-reamers

Standard dies may not form brass that will chamber. A case forming die is needed for some cartridges.

The loaded rounds outside neck diameter should not be larger theN  .334"  IF LARGER,  REAMING MUST BE DONE.

How does that factor in on my progressive?

I use more than just my Dillon dies.

With single stage shell holders, the height of the shell holder (and the height of the "deck" that the case head sits on) can vary between manufacturers.  That can lead to not being able to size a case down enough.  And since every die maker has their own shell holder numbering system, having their shell holder keeps you from having to look up "what RCBS shell holder is the equivalent of a Hornady #16?"

On a progressive, there is a similar situation, but fortunately both Dillon and Hornady progressive shell plates seem to have plenty of clearance.  Instead, the bigger progressive problem is die length; can you adjust the die down far enough, given the height and thickness of the toolhead and deck?

I think that, as long as you use a consistent shell holder with a particular set of dies - and if you are able to get sufficient sizing with that setup, then you're fine.  But while I have not always followed this advice, I'm working on correcting it for my own dies.  I "went cheap" with a lot of dies and didn't bother to get the shell holder when I bought the dies because I had a shell holder that would work for the new caliber.  

That's a big mistake if you have more than a couple sets of dies.  Where's that shell holder?  Did I leave it in the .223 box, or the 380 Auto box, or maybe the 300 Blackout box?  I have that issue, but with a number of different shell holders...

So at least get one shell holder for each set of dies, and preferably the die maker's shell holder.  It sure helps to decrease confusion, saves time searching for that darned shell holder, and since they're $5-$7 each, it's really cheap to keep up with.  Unless you're catching up, like me.

You're fine. I think he's talking about single stages where she'll holders are a little more standardized (assuming so, I've never owned a single stage).

I don't use any dillon dies for rifle and I only load on a dillon. Zero issues with a dillon shellplate and hornady/lee dies.

RCBS converts more consistently over anything else.


I've been able to use super thick cases .

https://www.mightyarmory.com/collections/sizing-dies/products/ma300blackout-sizing-die-pre-order-welcome



https://www.whiddengunworks.com/product/seating-die/#select-your-caliber

RCBS is what you seek

Just remember that competition type seaters do not have crimp function, and in order crimp a separate die will be needed.  Which, IMHO, is the best way to load. Seating is one separate step and crimping a another complete separate step.
Every one has their own ideas

The best dies out on the market are Redding.  They offer many options that LEE, RCBS, Hornady, and Regular Lyman dies do not.
Like carbide expander balls for most calibers 20-338 (Lyman offers a carbide decapping rod assembly, too and it also fits RCBS sizer die.
Redding has Micrometer seating stem that comes in standard or VLD style.
Hornady has their micro just seater stem, but then only VLD type options are for their bullets

Hornady’s web page entry for the Microjust stem is not well written.  The Microjust stem replaces ONLY the adjustment stem, not the actual bullet seating punch insert, which they also call a “stem”.
Emphasis added.  See this page for the product listing.

That said, they don’t offer a punch for every bullet in the world, so there may be some compromising to do now and then.

A Sheridan case gage is a good idea for 300 BLK, and a lee factory crimp die for cast bullet loads.

Arfcoms told me to buy Hornady and they have worked very well for me.

These suggestions are on point! I use the FCD for almost all rifle things.

Yes, I did get a shell holder to and a lee factory crimp die.