Sinclair’s expander mandrel instructions are a little vague. I use it for several cartridges now and only have one die body, so switching the mandrel and depth of the die seems like a necessity. The instructions say to thread the die in one inch, or until it touches the brass, then continue however much you want to expand. So far I have just been running up a piece until I see the lube line on the mandrel has gotten to the point where the entire neck has been expanded, however, this takes time and is kind of a pain. Ideally I would find a goldilocks setting for everything but I know if that’s ideal. Longest I’m running right now are 308 based cartridges and the shortest is 6BR. Curious if y’all worry about changing or just leave it at a set depth, or for those who change depth, is there a faster way of doing business?
Sinclair Expander Setup
- Thread starter txguero
- Start date
There is no way to avoid screwing the die in and out and testing.
You can screw it in too far and then screw it out until you no longer bottom out.
But that’s just working the problem from the other end.
You can screw it in too far and then screw it out until you no longer bottom out.
But that’s just working the problem from the other end.
I’m sorry, but I just cannot understand how this takes you very much time? Are you changing cartridges every 50 casings?
Take a depth reading on the lock ring for each cartridge, write it down, and use an easy ring like Hornady.
Actually. Just use Hornady lock rings anyway.
Take a depth reading on the lock ring for each cartridge, write it down, and use an easy ring like Hornady.
Actually. Just use Hornady lock rings anyway.
Best case scenario is that you set your die for the longest pieces of brass you'll size and test to see if it fully engages your shorter brass fully. You may get away with it but it will require some checking and measuring on your part. I do this on similar brass lengths such as my 260 and 308 but their brass is very close in length.
yes a lot of times I am changing cartridges that often. The main concern is going from 6BR to 308 length cartridges. I either don’t hit the full neck of 6BR or I run the mandrel way too far down into the neck of the 308 length cartridges. If that has no ill effect and I’m not bottoming out I guess it doesn’t matter and I won’t worry about changing around.
Oh no, I totally agree that bottoming out is a BAD idea. More dies is probably the easy button.
Make sure you leave the casing on the mandrel for a few seconds. Or 5.
Just a thought. Set it for the shortest case and use shims/washers beneath the lock ring for the longer cases.
Running the expander down the full length has no adverse effect. It's the same diameter the entire length. The only real issue is you will crush the case if the die is screwed down too far.
Extra die bodies aren't that expensive relative to all of your other reloading tools.die
Another option is to have a machine shop mill a slot in the side of the die so that you can actually see the the position of the mandrel relative to the case. Since all the die is doing is guiding the case, you really aren't jeopardizing the integrity if the die. I saw a video that used a die machines like that.
Extra die bodies aren't that expensive relative to all of your other reloading tools.die
Another option is to have a machine shop mill a slot in the side of the die so that you can actually see the the position of the mandrel relative to the case. Since all the die is doing is guiding the case, you really aren't jeopardizing the integrity if the die. I saw a video that used a die machines like that.
I personally run different die bodies and mandrels for different calibers. If you wanted to swap it around the quick way to set the depth is to put a piece of brass in the press and lower the ram, then screw the die down while looking down the top of the mandrel die with no expander in it. You can see when the brass gets close to interfering at the top, then back it off a bit from there.
I don't see how a longer dwell time is going to adversely affect the mandrel? IF anything, dwell time is going to help right?
That being said, as long as you're not bottoming out, why does it matter?
I wouldn't try and over think this.
A new die body is $30... Id just get another one man
That being said, as long as you're not bottoming out, why does it matter?
I wouldn't try and over think this.
A new die body is $30... Id just get another one man
I use the expander mandrel for 223, 308, 30/06 and 300 Win Mag. I use one mandrel body. This is what I figured out to use the one mandrel body with all.
I initially set the body up with lock ring at a height that will work for 223 and 308. To adapt to the height difference of the two, I set the body for 223 where the expander mandrel just goes to the bottom of the 223 neck, not any deeper. At this setting, It works for 308Win. also. The .30 mandrel does go deeper into the 308 case, because of the case length differences, but there is room on the .30 mandrel length where you don't run out of room and bottom out.
I then took an old die lock ring and with an added die shim or two (the shims that Redding makes for switching a 38 die to 357 and 44 spl to 44 mag) I was able to use the die ring and shims to shim the expander body to a height where it works with 30/06 and 300 Win. Mag.
Can switch back and forth in seconds to the two set heights, just spin on the die ring and shims to butt up against the initial locked die ring. Took a while to get it figured out, but it works great. I have a note in the mandrel die box on what shims to use for the longer calibers.
Last edited:
Does it matter if it goes just past the neck or 1/2 or 3/4 the way into the body of the case? I just got one and assumed that as long as I’m not slamming the top of the case into the mandrel and bottoming it out then it’s all the same?
Generally, you are correct. That being said, ASSUMING that the mandrel is perfectly uniform in diameter along the length.... I don’t assume sh#*. That’s what micrometers are for.
But as long as you run your casings in the same distance, should be good.
So... stupid obvious way to determine the dept of penetration of the sizing mandrel.
Remove the top cap of the Mandrel die, but keep the mandrel in location. Place a round in the shell holder and run the ram up to it's max point of travel.
Screw the die down. As the mandrel begins touching the top of the neck, it will begin lifting from the body of the die (remember, the top cap is removed. When you are happy with the height of protrusion, which will translate to the depth of penetration - Run the ram to the down position, Screw the top cap on, and mandrel size away.
There is little to no guessing if the correct amount of depth is achieved or not. And there's no reason to mess with lock rings or shims or counting turns or soothsayers.
Andrew
Remove the top cap of the Mandrel die, but keep the mandrel in location. Place a round in the shell holder and run the ram up to it's max point of travel.
Screw the die down. As the mandrel begins touching the top of the neck, it will begin lifting from the body of the die (remember, the top cap is removed. When you are happy with the height of protrusion, which will translate to the depth of penetration - Run the ram to the down position, Screw the top cap on, and mandrel size away.
There is little to no guessing if the correct amount of depth is achieved or not. And there's no reason to mess with lock rings or shims or counting turns or soothsayers.
Andrew
Similar threads
