Ive been shooting 500 already cut/sized blackout brass for a few cycles now that I bought a while back and I have about 1000 5.56 cases I want to convert. Seems like no one has the same info...

I planned on cleaning, using the cut jig (from 300blk talk) with a HF saw, resizing then trimming (tri-way).

What all needs to be done to the primer pockets? And what am I missing?

I pour cleaned lubed 556 brass into my hopper and run it through my 1050 with a Dillon trim die and 1500 trimmer. Its like a miracle.. comes out 300BO brass.

OK, there is a little more to it and you can use a 650 or even a 550 or LNL but you get the idea.

Save yourself the money on the jig and saw and trouble and do it the easiest way.

My take on it is to cut top off case, lube it, and run it into a 300 die,,  trim it..

As far as primer pocket,,,, it it .MIL brass, remove remnant of crimp from primer pocket and carry on... if commercial brass, they aint crimped 99% of time

^same here with the addition of a Lyman m-die located after the RT1500.... tough combo to beat.

It's then wet tumbled and  reloaded either on a xl650 or s1050.

~g

When making 300 BO, I chop the neck off, clean up the cut, anneal, form, trim to final length, then skim the necks with a neck turning tool.  There's a few makes of brass out there that make really thick necks after forming.  Necessary?  Probably not, but it's something i've started doing.

Everyone does it different.  I am frugal (wont buy a 1050 let alone a RT1500).

Sort cases (remove undesirable headstamps, PPU etc)
Deprime cases on universal decapper
Rough cut (just above shoulder)
Wet tumble for 3 hours
Chamfer and debur what remains after tumbling
Anneal
Lube
Double strike size
Swage primer pocket for Mil brass
Tumble off lube
Trim with TriWay
Final inspection, measure neck thickness (<.014)

Load

Before I got my 1500, this is how I did it. It is easier to feed sized 556 brass through the jig in my experience but that adds a step.

Some here like to add a step of annealing before they run it through the 300BO sizing die. I never did. I am certain it will help based on stuff I have read but it it depends on the accuracy you are going for. I am just as certain that I could hit a moving creature just as well with the ammo I make compared to those who anneal.

fill casefeeder turn eveything on and watch the auto drive run at 900rph, tumble brass again and load , quick , easy and simple

1.) Chop.
2.) Lube.
3.) Full length size it + deprime (I don't worry about the chop saw burrs before sizing).
4.) Trim.
5.) Chamfer + deburr.
6.) Swage.
7.) Clean the primer pockets.
8.) Tumble it.

Prepped brass!

I don't anneal or neck turn 300blk.

What are your annealing steps? I assume most don't have a heavy duty machine. I see a lot of people not even doing it but if I can find an easy way I will since I have a box of torch propane in the garage

http://www.ar15.com/forums/t_6_42/439440_Low_budget_Annealing.html


I anneal 577 Snider using Dryflash's method (link above). Works good. Not "fast". But works. In theory, you should only have to do it ever few firings. First one might be most important since you are forming cases.

To the guys who do not anneal before forming the shoulder:  I got about 1 in 5 split necks when forming before I started annealing.  Now I get zero split necks.  This was with WIN NT .223 brass.

I cut off with a dremel, run it through the sizing die which is is decapped at the same time, trim, re-cap and then load, Never any problems with splitting, then load with H110 and 125 gr Ballistic tip.  Turns out a very accurate load that takes deer down with no problem.

LC brass... formed about 3K no anneal. Not a single split.

splits on forming or shooting?

I wasn't converting 1x brass.  The lot of WIN NT had been fired at least twice, maybe 3x.  And I bet the first anneal on WIN NT isn't as good/perfect as LC.  And of course it had been work-hardened by 1-2 reloads.  I typically convert well-used brass for 300blk.  I'm typically loading low pressure/subsonics.

Sort brass - I am using LC brass, has already been twice fired, so no primer crimps.
Deprime w/ Harvey decapper
Wet tumble
Cut with HF trimmer with an Ebay jig cut to 1.375
Chamfer and debur
Lube case
Run through resizing die
Trim to length 1.360
Chamfer and debur
Prime
Add powder
Seat bullet
Lee FC crimp

I'm sort of in the middle of the pack on this.  I select brass to some extent, but not obsessively.  I have tested a bunch of different headstamps, particularly a number of the "bad brass" headstamps from 300BlackTalk's list, as well as converting specific commercial and military cases - none of them has given me a problem.

I have a Zep jig, and it doesn't seem to care if the cases are sized beforehand.  It's mounted on a Harbor Freight chop saw that has been easy to use and quite comfortable - though it tosses case parts pretty hard!  I chop the cases intentionally just slightly long.  Once my cases are chopped, I use dryflash3's low dollar annealing process and anneal each one.  In my first batch, I didn't anneal and it was considerably harder to form the cases than with brass I'd annealed.  Annealed cases are lubed and sized/formed in a standard 300 Blackout sizing die.  Once they're sized and de-lubed, I trim them with my Giraud Trimmer - the only catch with this is that there's not much case to hold onto, so I wear rubberized gloves to enhance my grip.

Obviously, I do this all in batches.  I have about 750 cases at the moment, and when I get a chance to finalize some loads, I'll probably convert a bunch more to load up.

I have a comment on brass that's been converted in one pass on a Dillon 1050: sure, it's quick and easy, but I worry about how well the neck is formed in this sort of process.  I feel that annealing is important to producing consistent cases, and I'm convinced that the expander ball in a standard sizing die is a crucial player in neck forming.  Plus there's the matter of how much brass chips each case will generate - a LOT - with the Dillon trimmer; I can see the chips being a real problem for the trimmer and its vacuum system.

Please explain "M" Die...

Did you miss a step between rough cut and wet tumble?

(Seems like you'd size before you chamfer and anneal.)

Yeah... no problem.

Normal sizing dies size the outside of the case, remove the primer, bump the shoulder, and then expand the neck on the upstroke.  The M-die allows me to expand the neck correcly after the brass has been reformed, this could be done during the reloading process with another pass thru a sizing die, but that would require additional lube during the reloading phase.

The RT1500 does not have a means for the neck to be expanded, it basically takes the 223 shell and forms it into 300BLK with the trimmer taking off the the extra brass, at no point in this process does the neck get expanded like a traditional sizing die would.  I made a bunch of sub-sonic rounds with the brass that I converted, but found them to be inconsistent at best.  Hoping the m-die helps with this issue.  I did 600 cases the other day, now I just need some time to reload and shoot it to confirm.

A lot of people who convert there own brass to 300blk use the m-die.

~g

Not really.  In this case you're not "annealing for neck tension", the way most people think about case annealing, you're annealing the part of the case that will be heavily worked in forming it to the new case shape.  It's actually one of the steps that case manufacturers do (repeatedly) during the various forming stages between raw brass and cartridge case.

I chop to rough length (always going a tad long), then chamfer to remove burs that can hang up the expander ball.  THEN I anneal the cases.  This not only reduces my perceived effort in sizing/forming the cases, it seems to me to give me more consistent neck thickness.  I have no evidence for this except my personal experience (posted above).

I don't bother tumbling the cases after chopping and before annealing because I wet tumble everything before I get to that step.

However, it's easier to handle .223/5.56 brass when removing crimps, so I'd do that before chopping them.  I found that out the hard way.  

The M-Die will give you MUCH more consistent neck dimensions.  It has a longish section that sizes the inside of the case neck to the desired diameter (usually a few 'thou below the bullet diameter, then a step that opens up the mouth just a bit, making it easier to start the bullet into the case.  I've used it very successfully for this particular caliber, and I'm using it with .30 Carbine as well - you use the .30 Carbine M-Die for 300 Blackout, since the case length is only a couple millimeters longer than the carbine case.