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What steps do you go through to resize your brass? While it's probably simple to most of you, I am having a hard time grasping what I need to do. I have watched and read what now feels like countless videos and posts but I just don't get the "correct" process. Do I want a FL die w/correct bushing followed by a mandrel? Or is a mandrel a personal choice? If it matters or helps I will be reloading for PRS in some flavor of 6mm. I would prefer if you explained it like I was 5.
But seriously your gonna get a lot of different answers here. Some guys use bushing dies, some a full length(expander removed) and mandrel, some run custom honed dies.
I personally haven’t used bushing dies I run full length followed by a mandrel and they haven’t held me back yet although it does add another step. More will come with the pros and cons of each.
Chose one and go. Get a normal full length sizing die and learn to use it. Then customize once you figure out what you’re doing and what you want to change
But seriously your gonna get a lot of different answers here. Some guys use bushing dies, some a full length(expander removed) and mandrel, some run custom honed dies.
I personally haven’t used bushing dies I run full length followed by a mandrel and they haven’t held me back yet although it does add another step. More will come with the pros and cons of each.
Chose one and go. Get a normal full length sizing die and learn to use it. Then customize once you figure out what you’re doing and what you want to change
This is great advice! All can create an accurate round it’ll come down to what fits best into your process as well as meet your goals. I started with a full length die than moved to pulling the decap pin and expander and use the mandrel instead to size the neck. I’ve yet to have this be the weak link in my shooting.
Bring brass home from range
Tumble in cob for 2 hrs
Anneal using AMP machine
Put in old .45 ammo tray
Spray with alcohol/lanolin mix to include a couple of angles down into the necks
Resize using full length, bushing dies with a .264 bushing and a decapping pin but no expander ball.
Mandrel necks up using a .241 mandrel
Wipe off lanolin
Done.
My .02 is that PRS isn't benchrest but does have some aspect of hard use mud, sand, grit etc. I've had good luck full length sizing, bumping shoulder back .002 and then resizing with a mandrel to give .001-.002 neck tension. Redding full length sizing dies and Sinclair expander mandrel. You can do it on a single stage and do it twice or on a progressive. Just need the dies, and some sort of headspace comparator tool.
Bring brass home from range
Tumble in cob for 2 hrs
Anneal using AMP machine
Put in old .45 ammo tray
Spray with alcohol/lanolin mix to include a couple of angles down into the necks
Resize using full length, bushing dies with a .264 bushing and a decapping pin but no expander ball.
Mandrel necks up using a .241 mandrel
Wipe off lanolin
Done.
Ok that's what I am getting hung up on. I do somewhat understand how to get the bushing measurement but what are you doing to get the mandrel? For the bushing you want to take a piece of loaded brass and measure the diameter then subtract .001"-.002" to get the correct number? So how do you determine what mandrel size you want?
My methods are elaborate for a beginner but the concept is the same;
De-prime the case
Run it through my industrial ultrasonic cleaner
Run it through the Autodod to check neck wall thickness
Run it through the AMP to anneal the case
Body die to bump the shoulder back and check with gauge/micrometer
Size the neck to spec with Redding micrometer bushing die
Run a mandrel to spec
Run it through the Giraud to trim to length, chamfer and deburr
Prime (I use a Primal Rights but there are many good options)
Charge with the ATv3 or ATv4 depending on the powder
Seat with a Redding micrometer die
Check double check COAL with a GOOD comparator
Shoot and enjoy the fruits of your labor.
Check out the book "Handloading for Competition Making the Target Bigger."
Ok that's what I am getting hung up on. I do somewhat understand how to get the bushing measurement but what are you doing to get the mandrel? For the bushing you want to take a piece of loaded brass and measure the diameter then subtract .001"-.002" to get the correct number? So how do you determine what mandrel size you want?
Some of that is trial and error until you get the neck tension what you want. I go with a mandrel .001" smaller than projectile diameter usually. With springback I get the tension I want. It can be case brand specific depending on the brass.
Ok that's what I am getting hung up on. I do somewhat understand how to get the bushing measurement but what are you doing to get the mandrel? For the bushing you want to take a piece of loaded brass and measure the diameter then subtract .001"-.002" to get the correct number? So how do you determine what mandrel size you want?
The bushing is an outside the neck measurement that takes the necks material thickness into account.
The mandrel is an inside the neck measurement that’s in relation to the bullet.
There are thickness variations and springback to consider as well if you’re going to get super fine with it.
Get a forster sizer die and use it. If you find you want it set for a certain neck diameter (like you would when selecting a bushing) then you can mail it in and have them hone it.
The bushing is an outside the neck measurement that takes the necks material thickness into account.
The mandrel is an inside the neck measurement that’s in relation to the bullet.
There are thickness variations and springback to consider as well if you’re going to get super fine with it.
Get a forster sizer die and use it. If you find you want it set for a certain size (like you would when selecting a bushing) then you can mail it in and have them gone it.
Ok that's what I am getting hung up on. I do somewhat understand how to get the bushing measurement but what are you doing to get the mandrel? For the bushing you want to take a piece of loaded brass and measure the diameter then subtract .001"-.002" to get the correct number? So how do you determine what mandrel size you want?
Sounds like you are on the right track with the inside/outside diameter deal. It is a bit of trial and error on the bushing/mandrel sizes. I usually end up with a bunch of bushings. I think I have .264-.267. My seated neck OD is .2685 as measured on my shitty calipers. I happened to have a .241 and a .242 mandrel from a neck turning setup. In benchrest shooting, I’ve used the .242 mandrel for super light, single-feeding only neck tension. But this ammo is magazine fed and needs to be able to take some abuse. So, after messing with various combinations with this brass and annealing process (both of which relate to spring back) I settled on 64/41. The .264 bushing is quite a bit smaller than I would expect to use but that smaller size causes a change in the spring back off the mandrel that leaves me with an acceptable, for my purposes, neck tension during seating. If I was more concerned about “overworking” the necks, I could probably get a .240 mandrel and use a .266 or so bushing. But I’m not concerned enough to buy another mandrel.
So, before you start making decisions, it’s important to know what you’re doing and what the goal is. And how we got there. I apologize if this is stuff you already know.
Let’s take virgin brass. It’s going to be smaller than your chamber. You’re going to prime/powder/seat (run a mandrel if you want, trim and such). Then you’re going to shoot it for the first time.
Now, you’re left with an empty case that is carbon fouled inside, has a spent primer, and has expanded closer to the actual size of your chamber (just depends on chamber, pressure, case hardness etc as to how close).
Now, the whole point of sizing is to do the minimal amount of down sizing as possible to get the desired fit in your chamber.
At a minimum you need the case to chamber easy as well as on the next firing have enough clearance to expand so the action’s primary extraction has no issues getting the case free for extraction.
I’m going to skip depriming, annealing, cleaning, etc. As each of those can be a separate topic.
So, now we have a case that has been prepped however you feel as far as the above things. It has no primer.
You will use your choice of lube (understand more/less lube has an effect on sizing). You’ll want the lube applied as consistent as possible across the casings.
So, now we have three part of the case we need to size (can be done with one, two, or three steps).
1: Body: this needs to be minimally sized down enough to chamber, fire, and expand….but not expand enough to get stuck. This is controlled by the body size in your die which was created using a sizing reamer (can Google those. Similar to a chamber reamer, just smaller in some dimensions).
Unless you spec a custom sizing reamer, you won’t have control of this. The die is what it is.
2: shoulder. You need to basically make the case length from base to shoulder short enough to fit in the chamber easily, and extract easily. However, you don’t want to make it too short. Otherwise it will stretch the body too much when fired which will make the body/head weaker. Eventually you will get case head separations.
I advice *NOT* to just push shoulders back a generic .002”. I suggest to use one of the several methods to check the fitment of your brass in the chamber (I personally use the wheeler method). Then decide what kind of fitment you want (I prefer the bolt to barely fall free with gravity). Then measure and see what the setback is. I’ve seen anywhere from barely .001 to .003.
3: Neck. So, the two above are basically done the same in a bushing or non bushing die.
The neck is where you choose which kind of die you want. There’s many thoughts on this. Sizing part of neck with regular bushing die, the whole neck with non bushing, or even the whole neck with some bushing dies that have a shoulder built into the bushing. I won’t go into it, as that’s also an entirely other topic.
You also have to decide how you want to set the final neck inside diameter/interference fit (commonly and incorrectly called neck tension).
- non bushing die with expander ball
- non bushing die without expander + mandrel after
- bushing die with expander ball
- bushing die without expander ball
- bushing die without expander + mandrel after
And then there are some sizing dies that have a mandrel inside instead of an expander ball.
If you turn necks and they don’t get beat up, you can use a honed custom non bushing die or a bushing die with the desired bushing. I typically don’t advice this on non turned brass.
Then the conversation goes into what size bushings and mandrels. But that’s also a whole other topic and it’s fluid. Change the bushing size and you’ll need to change the mandrel. Don’t anneal or change the spring back and/or hardness of brass, will need to chang other things.
Anyway, that’s the “what, why, and how” of sizing brass.
Once you understand this, then picking your equipment is much easier and just a matter of research, learning, and testing what you prefer or works best for you.
Full Length Sizing Die (FL Die): Simply insert the case into the lubed shell-holder, raise the ram to insert the case fully into the die and it will resize the entire case to dimensions which I consider "works in everything dimensions".
The main body of the FL die will shrink the neck down from the outside TOO much on the up stroke (putting more than necessary stress on brass) to make up for variances in case neck thickness.
Then on the down stroke the expanding ball (the bulge at some point along the de-capping rod) will set the final internal diameter (ID) of the case neck from inside the case to 0.00X" under bullet diameter so the bullet doesn't fall out, but not too tight you deform or damage the bullet during seating. But here's the catch, automatics need a tighter hold on the bullet (compared to bolt actions) because of that spring ramming the cartridge into battery. So FL Dies are set to that heavier hold on the bullet, which is less than ideal for bolt actions, but good for autos.
The expander ball generally does in my opinion (IMO) everything unevenly for a few reasons like it being tightly held off center, sizes one part of the neck at a time leaving the rest unsupported, tugging on the brass necks enough to pull your shoulder back out etc.
No control over neck tension (neck ID).
(Full Length Sizing Die - Expanding Ball) + Expanding MANDREL: Remove expanding ball from your FL die (on some FL dies, this includes the de-capping pin as well) and remove primers in a separate step with a de-capping die if necessary, then insert the case into FL die as before, but now instead of the expander ball setting your neck ID, you go to a separate step and you use a (mandrel die body + selected size expanding mandrel) which is a cylindrical rod with a rounded nose inserted into the mandrel die body which sets the final neck ID.
The main body of the FL die will shrink the neck down from the outside TOO much on the up stroke (putting more than necessary stress on brass) to make up for variances in case neck thickness.
Solved: because you can get different sized mandrel to tailor "bullet hold" to the application. (i.e. Auto vs Bolt).
Solved: because mandrel is free floating and self aligns. Also as the nose of the mandrel is inserted into the case expanding the neck, everything behind the nose is supported until finally the entire case neck is supported by the mandrel and errors tend to smooth themselves out. Lastly, the mandrel is pushed into the case and not pulled out like and expander ball and I generally find mandrels don't screw with my shoulder setback while expander balls do on occasion.
Solved: (see #2 explanation).
(Honed Full Length Sizing Die - Expanding Ball) + Expanding Mandrel: Same as above, except replace FL die w/ a FL die that you specify how much your brass is initially sized down *at the case neck*, usually tailored to your brass case neck thickness. These are custom machined dies, Forster offers this service, not sure of others. Some people leave the mandrel out and set final neck ID with the honed die body, but then IMO you're just shoving any inconsistencies on the outside to the inside instead of vice versa. And if you leave the expander ball on a honed die to solve this, well lets just say we already know how I feel about those.
Solved: because you specify how much you initially shrink your neck down, which can be tailored to your brass neck thickness, thus leaving less work for the mandrel, thus putting LESS stress on the brass.
Solved: (explained above).
Solved: (explained above).
Solved: (explained above).
New: How much your neck is sized down is fixed. So it's a good idea to have your thinnest piece of brass sized so the honed die leaves the case neck ID ~0.002" smaller than your mandrel size. If however this is an issue for you, then you'd look at bushing dies.
(Bushing Full Length Sizing Die - Expander Ball) + Expanding Mandrel: Same as above, except replace FL Die with a bushing FL die, where you swap bushings out to specify how much your brass is initially sized down.
Solved: because you specify how much you initially shrink your neck down, which can be tailored to your brass neck thickness, thus leaving less work for the mandrel, thus putting LESS stress on the brass.
Solved: (explained above).
Solved: (explained above).
Solved: (explained above).
New: Doesn't size all the way down case neck. Leaving that little bit of case neck near the shoulder unsized though does help with donuts but IMO the mandrel shoves that to the outside and if you neck turn then it gets cut off.
New: Some people have reported concentricity issues. Main reason to go with a honed die over a bushing die.
P.S. If how the aforementioned dies work is still unclear (which I feel was your main question), they ALL perform the desired action by inserting a case into the die. The case is inserted into the die via the ram on the up stroke, and extracted from the die via a shellholder securely attached to the ram on the down stroke.
The spoilers I felt was unnecessary information in regards to your rather straightforward question, but I was unsure your level of knowledge, so I decided to include it, if you needed it, as they offer some useful context before moving onto the next type of resizing method.
Lube it
Stroke it into the hole, wait a second, pull it out.
Stroke it into second hole, pull it out, turn it 90 degrees and stroke it in again, pull it out, wipe it off.
Done and time for a
Keep it simple until you learn.
Fl size with minimum shoulder bump.
Don’t listen to the die instructions it’ll have you sizing too small.
I tried to share Eric cortina’s die set up video but it’s not letting me.
Check it out on YouTube, it’ll show you how to set it up.
I'm not too proud to admit I use Redding comp shellholders to set shoulder bump. I like my die bottoming out on a shellplate, and these seem to give me the best outcome. I also use LE Wilson case gages and micrometer because, once again, I find they give me the best measurement as to what is happening to my shoulder when resizing. In fact, I often find I end up bumping the shoulder back a bit less (as in screw the die down less) when setting with the Wilson gages for .002 to .003 than I do when using caliper based systems. And no, I don't know why, but I have given up on understanding some things.
Keep it simple until you learn.
Fl size with minimum shoulder bump.
Don’t listen to the die instructions it’ll have you sizing too small.
I tried to share Eric cortina’s die set up video but it’s not letting me.
Check it out on YouTube, it’ll show you how to set it up.
Reasoning I mentioned reading the manual is it sounds like he has absolutely no experience reloading and needs to start someplace and sounds overwhelmed. He needs to get a basic understanding of whats going on and how he will get to the end result?
Reasoning I mentioned reading the manual is it sounds like he has absolutely no experience reloading and needs to start someplace and sounds overwhelmed. He needs to get a basic understanding of whats going on and how he will get to the end result?
I completely agree, but I don’t want him to be on here a month from now with case separation panic questions.
Everything else in the manual I don’t have a problem with. I don’t want to muddy it it up to bad for the op but I do believe Eric’s way of setting up the die is the proper way.
