Help me on purchase and process using mandrel expanding die

[Bigeclipse]

I typically use normal rcbs or redding full length sizing dies. I am going to give using a Sinclair expanding mandrel die set a shot. Here is what I think I need to buy and how I think it works. Please correct me if im wrong.

List to buy: Sounds like I will need any sizer type die and a decent bullet seater die (I will likely buy a redding 6.5prc die set). I will need to buy a decapping die. I will need to buy the Sinclair mandrel expander die and the size mandrel I will use (in this case a 6.5mm).

Process: Remove the decapping/sizer stem from the Redding full length sizing die. Deprime all the brass with the depriming die. Full length size all brass using lube and the redding full length sizing die. Then expand the necks using the Sinclair expanding die with the appropriate mandrel. Then move on to the rest of the reloading process.

Question 1: Are the carbide expanding mandrels worth it (50$ versus 10$ for steel)?
Question 2: Am I missing something else I need to buy?
Question 3: Is this process how I should be doing it?

 

[milo-2]

I'm not going into this very far, but I would look to 21st Century for my goods. Here's a link of some of their mandrels, step size .0005".
http://www.xxicsi.com/expander-mandrels.html

Not going to look on Brownells but in the past they had one size fits all turning and expander mandrels.
On whether carbide is worth it, IF, big if, you found the size you wanted that worked, IMO, buying the one would be worth it. But buying carbide to test with, be rather expensive. I have one PMA carbide, I know the cost was 70 to my door.

 

[Bigeclipse]

I'm not going into this very far, but I would look to 21st Century for my goods. Here's a link of some of their mandrels, step size .0005".
http://www.xxicsi.com/expander-mandrels.html

Not going to look on Brownells but in the past they had one size fits all turning and expander mandrels.
On whether carbide is worth it, IF, big if, you found the size you wanted that worked, IMO, buying the one would be worth it. But buying carbide to test with, be rather expensive. I have one PMA carbide, I know the cost was 70 to my door.

Why do you suggest these over the sinclairs? From what I have read the Sinclairs are highly rated?

 

[milo-2]

Why do you suggest these over the sinclairs? From what I have read the Sinclairs are highly rated?

I am sure they are good, one more time, I am not sure what all Sinclair offers. If it is still one diameter, and you feel that is the ticket, by all means buy one.
I just gave you some thought options.
In the past, expander mandrels were .002" under caliber dia, bullet dia is never caliber diameter, so I have never figured how anyone achieves .002" neck tension using one, which has always been the claim. Then figure in necks thin after first firing, blah blah.

 

[cjl2010]

That's the setup I use. I use a carbide turning mandrel as its .002 under sized. As of lately I have been dipping case mouths in dry lube. I noticed without lube the necks get pretty warm when expanding. I bought some imperial dry lube that I also use on virgin brass to expand necks.

 

[Bigeclipse]

That's the setup I use. I use a carbide turning mandrel as its .002 under sized. As of lately I have been dipping case mouths in dry lube. I noticed without lube the necks get pretty warm when expanding. I bought some imperial dry lube that I also use on virgin brass to expand necks.

do you use Sinclair mandrels? Because I watched a video and they said the carbide ones are actually .0015 under sized and not .002?

 

[Orange Dust]

That's the setup I use. I use a carbide turning mandrel as its .002 under sized. As of lately I have been dipping case mouths in dry lube. I noticed without lube the necks get pretty warm when expanding. I bought some imperial dry lube that I also use on virgin brass to expand necks.

I don't use the carbide. Really don't get the advantage since they need lube too. I also use the turning mandrel. .001 smaller than the expanding mandrel. You don't need a decap die. If your die has an expander ball like Forster, remove it. If the expander holds the decap pin just steal an undersize one from another die set or buy an undersize one. In your case anything from .257 or smaller will work fine. I have found this to be worth the trouble. I use Hornady one shot for lube. Hold the can at about a 30 deg angle and lightly spray the case mouths in a loading block.

 

[Whiskey_Tango]

I have a Lee FL size/decap die, expander ball and decap stem are solid one piece. I just took a few thou off the expander ball and follow the FL die with my mandrel die.

I just use Hornady one shot.

Pretty low rent setup, but I've had good results.

 

[Bigeclipse]

I don't use the carbide. Really don't get the advantage since they need lube too. I also use the turning mandrel. .001 smaller than the expanding mandrel. You don't need a decap die. If your die has an expander ball like Forster, remove it. If the expander holds the decap pin just steal an undersize one from another die set or buy an undersize one. In your case anything from .257 or smaller will work fine. I have found this to be worth the trouble. I use Hornady one shot for lube. Hold the can at about a 30 deg angle and lightly spray the case mouths in a loading block.

I don't intend on turning my brass so is using the turning mandrel have any advantage if not neck turning?

 

[Orange Dust]

One more thing. Doing this improves consistency in neck tension. It also lowers bullet runout. I have serious doubts that the runout part will improve accuracy unless you skim turn the necks. Ditto on the consistency. When skim turning, you only want to take metal off 50-60% of the neck. In other words knock off the high side. I do this for all cases for my long range rifles unless they require a turn neck to a specific dia. I feel doing this is a necessary step to getting the most benefit from using the expanding manderl die. Once you set the cutter, keep it the same for every case you have, no matter how much it takes off.

 

[cohunt]

Turing mandrels are .002" under bullet diam, Expander mandrels are .001" under (sinclair) --you can use either to set proper neck tension-I tend to use the expander with lead core match bullets and the turning mandrels for hammer hunter bullets

the 21stC mandrels are marked with a size, and they go from .001" above diameter to .003" under bullet diameter and are available in .0005" increments-- they would be more "exact" than the sinclair ones

do the 21st century mandrels fit in the sinclair die?

 

[Orange Dust]

I don't intend on turning my brass so is using the turning mandrel have any advantage if not neck turning?

Think about it. If all the necks are not the same thickness, How can tension be the same? You do get springback. Also, it seems to me that if the necks are straight and round on the inside before firing, they won't be afterword when the bullet is leaving the case. I'n not saying it won't help doing it anyway. You just won't reap all the benefit. I use a Forster trimmer with a neck turning attachment, and trim at the same time. Really doesn't take any longer than trimming, and you should trim all your new cases to a uniform length any way. I really don't see a downside to it since it only has to be done once, and you need to trim them and square the mouths anyway. Here is how I process a new batch of cases:
First I debur the mouths
Then I ream the primer pockets and debur the flash holes
Then a trip through the neck expander die
Then turn necks and trim in one pass through trimmer
chamfur and debur necks again
Then full length resize
Another trip through the neck expander.
Weigh and sort
Load.
Sounds like a lot of trouble but its really not, adds maybe an hour or so to a batch of 100 cases. Good cases are expensive but a couple of hundred will outlast most barrels,so it isworth the time and effort IMO.

 

[cohunt]

if you use a bushing die with no expander then neck turning seems to help-- with the expander mandrels, I havent noticed a huge difference --I skim turn all of my cases though (except 223 AR plinkers) -- neck tension does make a different for me, other people dont seem to care

I feel that anything that helps consistency can help accuracy-- but often times all of these processes add time and at some point there seems to be a diminishing point of return on the time it takes for certain processes --- thats why each of us seem to have a slightly different process, they have learned over the years what seems to help them the most

 

[Orange Dust]

if you use a bushing die with no expander then neck turning seems to help-- with the expander mandrels, I havent noticed a huge difference --I skim turn all of my cases though (except 223 AR plinkers) -- neck tension does make a different for me, other people dont seem to care

I feel that anything that helps consistency can help accuracy-- but often times all of these processes add time and at some point there seems to be a diminishing point of return on the time it takes for certain processes --- thats why each of us seem to have a slightly different process, they have learned over the years what seems to help them the most

Gets rid of the flyers for sure. I also coat all my bullets with HBN. That stuff is great and solves a lot of problems I didn't know I had before I started playing with it. What I have found more than anything with cases prepped this way and HBN is consistent groups on different days. The gun doesn't shoot 1/4" one day and 3/4" the next. It pretty much shoots the same all the time unless I've had too much coffee or something. I quit shooting groups anyway when I finish my load development. Once i'm done, if the bullet doesn't go where expected, you can bet it was the nut behind the trigger that was at fault. Makes it so much easier for me to improve my shooting. Mentally, It's "What did I do differently"? Shooting never becomes boring because there is always something for me to learn. That's why I just love this site. I've learned a lot about optics, rifles, and loading. There are a lot of folks here that know a lot more than I do, and I've been at this almost 50 years. I often wonder how it would have turned out if we had everything available to us 50 years ago that we have today. Wow!