making 300 BLK from 556

[cmoore806]

Ive searched and not found so heres my post. Instead of buying 1k-2k 300blk brass I want to convert from 223/556 on my 650. I need to develop a plan and need more experienced reloaders advice.

So far I've come up with:

decap 223/556 in 650 with lee universal decapping die
wet tumble
dry
swage primer pockets, sort by headstamp
lube cases
run through 650 again trimming/sizing with carbide die and Dillon 1500 trimmer
clean cases somehow (wet tumble?)
Anneal with AMP annealer
Load cases (prime, powder, press bullets)

Ive thought about just cleaning the collected range brass first before decapping so I just run it through a decapping die and trimmer in the same step, then I would save some time not having to run through the 650 twice.

 

[roostercogburn98]

I have an aluminum cutting guide I use to cut the 223/556 cases using a 2 inch chopsaw. I also have a dedicated set of dies I use to shape 300BO. Maybe that is overkill but just the way I started it. I have never bought a commercial loaded or formed 300 BO round either and I have played with the caliber since 2009 ish. Will post some pics of my cutting setup once I get back home

 

[padom]

Well if your serious about making quality 300blk from 5.56 this is your easiest way and fastest way. This is a video I made processing 6.5cm gasser brass on my 650. I convert 300blk this same way.

Dedicated 300blk Dillon toolhead. Decapping die, then FL Trim die setup to form 300blk shoulder with .003 bump headspace, squeeze down neck, and trim to length, then mandrel in last station to set .002 neck tension.. all you have to do is chamber and debut before loading..

 

[padom]

I have an aluminum cutting guide I use to cut the 223/556 cases using a 2 inch chopsaw. I also have a dedicated set of dies I use to shape 300BO. Maybe that is overkill but just the way I started it. I have never bought a commercial loaded or formed 300 BO round either and I have played with the caliber since 2009 ish. Will post some pics of my cutting setup once I get back home

Did this once. What a mess and slow as hell. Nothing faster than the 650 with RT1500 trimmer and trim/size die.

 

[cmoore806]

yeah I already have the 650 and the 1500 trimmer and die I need. Im wondering when the best time to anneal would be.

 

[padom]

yeah I already have the 650 and the 1500 trimmer and die I need. Im wondering when the best time to anneal would be.

I anneal 1x LC brass half down to where the shoulder will form... then process on the 650 then SS tumble...this is the final product.

 

[cmoore806]

I anneal 1x LC brass half down to where the shoulder will form... then process on the 650 then SS tumble...this is the final product.

Im afraid this isnt an option with the AMP annealer since the pilot would be setup for 300 BLK. Probably would need a torch based annealing system to anneal prior to trimming.

 

[padom]

yeah I already have the 650 and the 1500 trimmer and die I need. Im wondering when the best time to anneal would be.

You have the special undercut toolhead you have to use for 300blk?? And a mandrel? The trim/size die gives way too much neck tension

 

[cmoore806]

You have the special undercut toolhead you have to use for 300blk??

yup.

 

[padom]

Im afraid this isnt an option with the AMP annealer since the pilot would be setup for 300 BLK. Probably would need a torch based annealing system to anneal prior to trimming.

Yep. I use the Annealeez and can load up a few hundred LC 5.56, put torch where I want and let it run

 

[cmoore806]

There may not be any option then but to run things through the press twice for case prep. In reality I have more time than money so probably should make my peace with it.

 

[NCHillbilly]

I have to admit ignorance on this subject. I also would like to be able to convert 5.56 brass to 300 bo, but only have standard rcbs small base 2 die set. After trimming to length, will these do the job, or will I need something else?

 

[cmoore806]

I have to admit ignorance on this subject. I also would like to be able to convert 5.56 brass to 300 bo, but only have standard rcbs small base 2 die set. After trimming to length, will these do the job, or will I need something else?

im also ignorant on the topic. I’ve only thought of using the Dillon trimmer and carbide die to make the 300BLK.

 

[NCHillbilly]

im also ignorant on the topic. I’ve only thought of using the Dillon trimmer and carbide die to make the 300BLK.

I guess I should have phrased my question as " will a std rcbs fl sizing die work or do I need some special forming die"?

 

[padom]

I guess I should have phrased my question as " will a std rcbs fl sizing die work or do I need some special forming die"?

Standard 300blk... your still gonna want a mandrel. If not using a dillon... I would chop 5.56 a tad long, anneal, runt through FL 300blk die with the rod removed, then do a final trim to length in your case trimmer, chamfer/debur then run into a mandrel to set neck tension

 

[NCHillbilly]

Standard 300blk... your still gonna want a mandrel. If not using a dillon... I would chop 5.56 a tad long, anneal, runt through FL 300blk die with the rod removed, then do a final trim to length in your case trimmer, chamfer/debur then run into a mandrel to set neck tension

Thanks. I don't have a dillon at the moment, still doing it the slow way. I've never had to actually form brass and was concerned that my dies might not be suitable for that. Another question, do you know if the rcbs decapping stem can be replaced with the correct sized mandrel, or will that require a different brand of die? I'm sure my die only has an expander ball.

 

[padom]

I personally would just get a 21st century turning Mandrel. Much easier. You may have issues trying to drag that ball out of the new neck that's all rough cut up. Much easier to use a true mandrel after you do your final trim

You want this one specifically. TiN coated 22cal turning arbor. Will leave you with .002 neck tension.

Arbors and Mandrels

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30cal Titanium Nitride Turning Arbor – Pt#NT30

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Expander Die Body

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[Sportin Wood]

This is what I do...

 

[NCHillbilly]

I personally would just get a 21st century turning Mandrel. Much easier. You may have issues trying to drag that ball out of the new neck that's all rough cut up. Much easier to use a true mandrel after you do your final trim

You want this one specifically. TiN coated 22cal turning arbor. Will leave you with .002 neck tension.

Arbors and Mandrels

21st Century Shooting, Reloading products, Reload, reloading ammo, 21st century, twenty first century shooting, shooting, gun arbors, mandrels, reloading, tools for reloading, front rest, f class, bench rest, short handle, arbor press, powder measure, bullet, bullet comparators, die base, shell...

www.xxicsi.com

22cal Titanium Nitride Turning Arbor – Pt#NT22

And you need the die body it goes in

Expander Die Body

21st Century Shooting, Reloading products, Reload, reloading ammo, 21st century, twenty first century shooting, shooting, expander die body, gun reloading, tools for reloading, front rest, f class, bench rest, short handle, arbor press, powder measure, bullet, bullet comparators, die base, shell...

www.xxicsi.com

Thanks a ton.

 

[padom]

I edited my above post... the mandrel model I posted is for 5.56. Edited it for the 30cal.one you need for 300blk..

 

[Eostech]

Im afraid this isnt an option with the AMP annealer since the pilot would be setup for 300 BLK. Probably would need a torch based annealing system to anneal prior to trimming.

You could try and contact amp for a custom made pilot.

Induction Annealing Wildcatting | Under The Microscope | AMP

View the latest articles from AMP Annealing. Get tips and tricks from our R&D. Here we upload articles to provide your the best possible information on innovations in the annealing process.

www.ampannealing.com

 

[cmoore806]

You could try and contact amp for a custom made pilot.

Induction Annealing Wildcatting | Under The Microscope | AMP

View the latest articles from AMP Annealing. Get tips and tricks from our R&D. Here we upload articles to provide your the best possible information on innovations in the annealing process.

www.ampannealing.com

I think someone else can ask them. I wouldn’t trust annealing brass while planning to remove the old case shoulder and mouth. I think there’s too many unnecessary variables solved by trimming first then using Aztec mode to analyze the trimmed down brass.