I asked this in a PM, but thought it deserved to be shared. Thank you @spife7980 as always for your help:
Me:
Hey Spife,
I figured I'd send you a PM and ask you a quick question instead of creating an entire post since you've been more than helpful so far.
My question is on the expander in a Redding FL S-type die, and expanding the ID of the case mouth in general. The big benefit of the S-type die seems to be using the bushings to set neck tension, and allowing them to 'float' to help with concentricity. However, with an expander ball bellow it wont the die expand, neck size in bushing, then pass back through the expander; leaving the bushing step somewhat pointless or altered by the expander? Can I just remove the expander and rely only on the bushing to form the case mouth?
And if the expander is necessary, are the Redding carbide expanders worth it or a gimmick? The potential to not have to lube the inside of the case mouth and worry about lube/wax contaminating the powder seems promising.
https://www.brownells.com/reloading.../carbide-button-kit-std-type-s-prod33284.aspx
Lastly, thank you for your help so far on the boards. Asking questions helps me learn, and I think you've jumped in on all of them so far.
Best,
Ryan.
Spife:
It all depends on what youre doing and what the diameters are. Doing the math helps.
Lets say we are using a 6.5 creedmoor with brass that has a neck .014 thick.
.264" bullet, brass neck is .014 on one side so both sides measure .028
.264+.028 is .292", thats the measurement of a loaded round.
Lets say a chamber is .297"
Your fired brass will expand from .292->.297
So, the question is how do we size the .297 piece of brass down and end up with our desired neck tension measurement (interference fit of the brass and bullet)?
Generally we try to size the neck to .002" smaller than our loaded round, .292-.002=.290"
If we use a bushing that measures .290 that pushes the brass smaller from the outside squeezing in. That will leave your neck the desired .290" which is .002 smaller than the loaded round. The issue with this is that since its pushing outside in it will push and discrepancies inwards. Lapua brass has about .001-.0015 of difference in neck thickness from one side to another, so if the outside is perfectly round than even the best factory brass will leave the inner circle with some spots that are .001 tighter than other spots, that leads to nonuniform bullet grip.
Now, Lapua with its .001 in difference side to side isnt that big of a deal, and people who turn their necks to a perfectly even thickness dont have this issue at all, they can just size down to exactly what they want and everything will be perfectly even. Thats why you see it recommended so much on benchrest forums they have added an entire process to the step to avoid having to use an expander ball. But the results from perfectly even necks back it up. Once you stat trying to shoot bench groups under .3 moa day in and day out I dont think the juice is worth the squeeze to turn necks though.
And the floating of the bushing isnt really to help with concentricity per say in that it improves it, the bushings are still prone to off center more than a reamed neck. But floating it just that tad allows it to move and let the brass dictate where it goes instead of pinching it off center and kinking every single piece of brass.
A bushing also has a slight bevel around the bottom so that the case mouth goes in smoothly instead of potentially running into a sharp edge and jamming. That bevel means it doesnt size the entire neck, it leaves a ring at the bottom thats larger in diameter. Its not a big deal though.
So, the next question for the rest of us is: how to get it sized smaller but also keep the inside surface that touched the bullet concentric? To do that you have to size from the inside, not just the outside. If you size the neck down so that the outside is a perfect .290 that would leave the inside as a perfect .262 (.290-.014-.014=.262). Expander balls are usually .002 smaller than bullet diameter, .264-.002=.262. So with that expander ball being the exact size of the inside hole it wouldnt really do anything. Yeah, it might touch some of the high spots or thick areas of the neck but not enough to really change the brass due to spring back. So, to get the expander to touch enough to actually size the inner neck and leave it perfectly round you need to size the neck down smaller and then reopen it up with the expander. That would mean buying a bushing that is .289 or .288 instead of the above .290 that the people above who turn their necks would opt to use.
So yes, it does alter what the bushing step does but that doesnt make it pointless. BUT the point of a bushing isnt how much work it does and saving it, the point is how much work it doesnt do. A traditional full length die might size that brass all the way down to .282 and then use an expander ball to open it back up to .290. That means the brass is going from a fired diameter of .297 and getting sized .015 to .282 and then getting opened back up .008 to .290. Using an appropriately selected bushing turns that .015 of down work into .009 and the back up from .008 to .002. It turns .023 of total work done to the brass to .011. It cuts the amount of work you do to that brass in half. That means that your brass will be worked much less and will last that much longer. And the more brass gets worked the more inconsistent it can become from piece to piece, so it helps keep the batch as a whole uniform.
You can open it up with an expander ball that goes inside and gets dragged through the small neck on its way out, or you can add a second step and use a mandrel. When using a mandrel instead of dragging the ball back out you force a rod in.
The carbide isnt a gimmick, it does exactly what it is designed to do. Whether you need it or not is a judgment call. I had been using a tradition expander just fine and then I started annealing. All of my cases worked just fine except for my lapua 223 brass. For some reason it made dragging a traditional expander super hard, like lifting the table my press is mounted to up off the ground hard. It took my whole body to get them out of the die. I started using the imperial dry graphite neck lube and that helped but it still wasnt great. I grabbed a carbide expander ball and I no longer needed to use the dry graphite. Carbide is super hard and super slick and can make a tough task easier, but unless you find you need it to be easier I dont think its worth the 30 bucks. I still use my lanolin spray lube (or oneshot) and spray into the mouths with the carbide, its too easy to not and tumbling cleans it up.
Me:
Hey Spife,
I figured I'd send you a PM and ask you a quick question instead of creating an entire post since you've been more than helpful so far.
My question is on the expander in a Redding FL S-type die, and expanding the ID of the case mouth in general. The big benefit of the S-type die seems to be using the bushings to set neck tension, and allowing them to 'float' to help with concentricity. However, with an expander ball bellow it wont the die expand, neck size in bushing, then pass back through the expander; leaving the bushing step somewhat pointless or altered by the expander? Can I just remove the expander and rely only on the bushing to form the case mouth?
And if the expander is necessary, are the Redding carbide expanders worth it or a gimmick? The potential to not have to lube the inside of the case mouth and worry about lube/wax contaminating the powder seems promising.
https://www.brownells.com/reloading.../carbide-button-kit-std-type-s-prod33284.aspx
Lastly, thank you for your help so far on the boards. Asking questions helps me learn, and I think you've jumped in on all of them so far.
Best,
Ryan.
Spife:
It all depends on what youre doing and what the diameters are. Doing the math helps.
Lets say we are using a 6.5 creedmoor with brass that has a neck .014 thick.
.264" bullet, brass neck is .014 on one side so both sides measure .028
.264+.028 is .292", thats the measurement of a loaded round.
Lets say a chamber is .297"
Your fired brass will expand from .292->.297
So, the question is how do we size the .297 piece of brass down and end up with our desired neck tension measurement (interference fit of the brass and bullet)?
Generally we try to size the neck to .002" smaller than our loaded round, .292-.002=.290"
If we use a bushing that measures .290 that pushes the brass smaller from the outside squeezing in. That will leave your neck the desired .290" which is .002 smaller than the loaded round. The issue with this is that since its pushing outside in it will push and discrepancies inwards. Lapua brass has about .001-.0015 of difference in neck thickness from one side to another, so if the outside is perfectly round than even the best factory brass will leave the inner circle with some spots that are .001 tighter than other spots, that leads to nonuniform bullet grip.
Now, Lapua with its .001 in difference side to side isnt that big of a deal, and people who turn their necks to a perfectly even thickness dont have this issue at all, they can just size down to exactly what they want and everything will be perfectly even. Thats why you see it recommended so much on benchrest forums they have added an entire process to the step to avoid having to use an expander ball. But the results from perfectly even necks back it up. Once you stat trying to shoot bench groups under .3 moa day in and day out I dont think the juice is worth the squeeze to turn necks though.
And the floating of the bushing isnt really to help with concentricity per say in that it improves it, the bushings are still prone to off center more than a reamed neck. But floating it just that tad allows it to move and let the brass dictate where it goes instead of pinching it off center and kinking every single piece of brass.
A bushing also has a slight bevel around the bottom so that the case mouth goes in smoothly instead of potentially running into a sharp edge and jamming. That bevel means it doesnt size the entire neck, it leaves a ring at the bottom thats larger in diameter. Its not a big deal though.
So, the next question for the rest of us is: how to get it sized smaller but also keep the inside surface that touched the bullet concentric? To do that you have to size from the inside, not just the outside. If you size the neck down so that the outside is a perfect .290 that would leave the inside as a perfect .262 (.290-.014-.014=.262). Expander balls are usually .002 smaller than bullet diameter, .264-.002=.262. So with that expander ball being the exact size of the inside hole it wouldnt really do anything. Yeah, it might touch some of the high spots or thick areas of the neck but not enough to really change the brass due to spring back. So, to get the expander to touch enough to actually size the inner neck and leave it perfectly round you need to size the neck down smaller and then reopen it up with the expander. That would mean buying a bushing that is .289 or .288 instead of the above .290 that the people above who turn their necks would opt to use.
So yes, it does alter what the bushing step does but that doesnt make it pointless. BUT the point of a bushing isnt how much work it does and saving it, the point is how much work it doesnt do. A traditional full length die might size that brass all the way down to .282 and then use an expander ball to open it back up to .290. That means the brass is going from a fired diameter of .297 and getting sized .015 to .282 and then getting opened back up .008 to .290. Using an appropriately selected bushing turns that .015 of down work into .009 and the back up from .008 to .002. It turns .023 of total work done to the brass to .011. It cuts the amount of work you do to that brass in half. That means that your brass will be worked much less and will last that much longer. And the more brass gets worked the more inconsistent it can become from piece to piece, so it helps keep the batch as a whole uniform.
You can open it up with an expander ball that goes inside and gets dragged through the small neck on its way out, or you can add a second step and use a mandrel. When using a mandrel instead of dragging the ball back out you force a rod in.
The carbide isnt a gimmick, it does exactly what it is designed to do. Whether you need it or not is a judgment call. I had been using a tradition expander just fine and then I started annealing. All of my cases worked just fine except for my lapua 223 brass. For some reason it made dragging a traditional expander super hard, like lifting the table my press is mounted to up off the ground hard. It took my whole body to get them out of the die. I started using the imperial dry graphite neck lube and that helped but it still wasnt great. I grabbed a carbide expander ball and I no longer needed to use the dry graphite. Carbide is super hard and super slick and can make a tough task easier, but unless you find you need it to be easier I dont think its worth the 30 bucks. I still use my lanolin spray lube (or oneshot) and spray into the mouths with the carbide, its too easy to not and tumbling cleans it up.
