300 AAC Re-forming questions...

[Jon Road King]

Ok, so I have decided to convert my AR-15 pistol (in 5.56) to 300 AAC as part of my next re-loading challenge. In my research I keep hearing about crushed or folded necks during the re-forming stage. And I am also coming up foggy on the exact process for re-forming 5.56/.223 to 300 AAC. So far, I have come up with the following plan, based on research:

Step 1 - Clean
Step 2 - Rough Trim with Harbor Freight 2" cut-off saw.
Step 3 - Re-size/re-form / De-prime with RCBS AR Series die
Step 4 - Final trim with CTS trimmer
Step 5 - Check with Sheridan slotted OAL gauge.
Step 6 - Carpal Tunnel stage on Lyman case prep center...
Step 7 - Reload

The 'fog' is the cut-off saw stage. Do folks re-size/re-form then just trim to correct length with the cut-off saw? Seems like that's a bit rough to me, but I might be missing something here. I mean, Harbor Freight? Yikes...

Also, is there an interim re-form die stage? Since I have a Hornady LnL, I could set up two dies to re-form in two stages instead of trying to crush the case down all in one die. And if so, what is a good size die for the in-between stage?

Thanks!

[John Browning]

I cut off, then reform but without the expander in the first die and then run it through a second die with the expander on my LNL. I have found I get fewer stuck cases that way. The chop saw will not work for anything more than the initial cut down.

[Jon Road King]

I cut off, then reform but without the expander in the first die and then run it through a second die with the expander on my LNL. I have found I get fewer stuck cases that way. The chop saw will not work for anything more than the initial cut down.

Kinda what I figured. What size die do you use on the first die?

[mif_slim]

My process is as follow:

1. Clamp to HF saw
2. Cut below shoulder of the 5.56 brass
3. Quick chamfer/debur Lee hand tool
4. Lube case
5. Goes right into Hornady 300aac full size die
6. Lee quick trim with 300aac length die.
7+ are normal reloading get process.

[2shotjoe]

My process is as follow:

1. Clamp to HF saw
2. Cut below shoulder of the 5.56 brass
3. Quick chamfer/debur Lee hand tool
4. Lube case
5. Goes right into Hornady 300aac full size die
6. Lee quick trim with 300aac length die.
7+ are normal reloading get process.

This what I do.

Sent from my DROID RAZR using Tapatalk

[Rac97crawford]

There are quite a few videos online of people doing this.
Like this one.
Watch "How to convert .223 brass to 300 BLK for cheap" on YouTube
How to convert .223 brass to 300 BLK for cheap: http://youtu.be/5rpx5XbqAgM

[thenodnarb]

Just a heads up that several of my resized 223 cases have split at the necks after forming. If I ever make any more, I'll be annealing after I size them but before the initial loading. These splits I found on some loaded ammo that I had for over a year but never fired. They might have been fired once, and reloaded. Don't remember, but annealing would most likely solve that problem.

[Sky_DiveR]

My process is as follow:

1. Clamp to HF saw
2. Cut below shoulder of the 5.56 brass
3. Quick chamfer/debur Lee hand tool
4. Lube case
5. Goes right into Hornady 300aac full size die
6. Lee quick trim with 300aac length die.
7+ are normal reloading get process.

Only thing I do different is anneal after sizing/trimming. I haven't had a problem after sizing/forming but it was recommended to anneal the work hardened brass. It was also mentioned that some 223 brass will split if you load without annealing. Thinner brass perhaps.

Some Military brass needs to be reamed due to the wall being too thick after sizing. I ran into that with another brand of brass not fitting the case gauge after loading. Haven't had that problem with Lake City brass.

Maybe the people that are having problems crushing brass didn't use enough sizing lube. I use Imperial Sizing Wax and haven't crushed any brass.

[samcam13]

I cut, anneal,form, trim, debur. Use only LC or WCC brass. I found that all my failures to chamber decreased after starting to use wcc or lc brass, and completely stopped after I started annealing. Just to be sure I drop every one into a sheridan cartridge go no go gauge to double check.

[Psychbiker]

Universal deprime lnl
Stainless tumble
Cut off
Lube
Size
Trim
Swage
Curse like a sailor
Load

[Bumslie]

Phase 1 - get .223 brass

Phase 2 - ?????????

Phase 3 - profit!

[rg1]

Just note that the cut-off length will grow 5-8 thousandths after running through your sizing die. Saves extra trimming if you cut them shorter to allow for the growth in length. Cut them 1st, deburr, run through your 300 Blackout sizing die. Sizes and forms in one easy step with no problems with force needed. I do highly recommend a headspace gauge. Difference in factory rounds sized minimally and some chambers can be from 7-8 thousandths so you do need to adjust the sizing die to form the shoulder to fit your rifles chamber. I recommend Hornady's Headspace gauge set which is used mounted to your calipers. You can adjust your sizing die to get the 3-4 thousandth headspace needed. Make sure your loaded neck diameter is .334" or less. Some brands have too thick case walls and necks can exceed the limit. Fun to load and fun to shoot.

[Kmai24]

My process may be a few extra steps but I don't mind it, I enjoy it

1-cut with HF mini chop then quick debur and chamfer using drill press
2-deprime
3-1hr SS wet tumbling (of course wait to dry then step 4)
4-lube with hornady one case lube (shake n bake style)
5-resize/form (hornady die)
6-trim(wft), swage (if necessary), debur and chamfer
7- 1-1/2 to 2hrs of SS wet tumbling

Used all types of mix brass from lc, wcc, and pmc just to name a few off the top of my head. All rounds have fed and ejected with no hiccups.

[Germz]

after doing about 1000 rounds of 300 black I'm kind of on the fence about the whole reforming.

a good lot of my cases, after sizing on my lnl ap are not consistent. I think the issue is the die to shellplate contact. I'm waiting to get a single stage to confirm thats the issue...

[PolishMike]

I had better luck personally by making a little jig for the brass in my drill press vice and chucking up a case trimmer bit. The depth stop was a lot more reliable for me than the chop saw.