Do I need to turn necks again?

[Deleted member 107666]

Turned necks before fire forming.

Ran these through a body die and now the thicker brass has pushed forward of the neck shoulder junction where I had turned necks to...do I need to turn these again back to the junction?

 

[bigedp51]

My guess is you pushed the shoulders back too far.

Note, if you trim your case off the shoulder with a WFT or similar the turning cutter will always stop at the same point.

 

[antelopedundee]

As long as there's no donut inside the neck at that point I wouldn't do anything.

 

[Deleted member 107666]

My guess is you pushed the shoulders back too far.

Note, if you trim your case off the shoulder with a WFT or similar the turning cutter will always stop at the same point.

According to the RCBS precision mic...the shoulders didnt bump back at all. From zero on the gauge, new the brass was .012 (reads .037) under the zero line (min saami), after first firing they expanded out .006-.007 inches and guage (now reads .043). The Redding body sizing die in my forster Co-Ax did not bump the shoulder from that .043 reading

 

[Deleted member 107666]

As long as there's no donut inside the neck at that point I wouldn't do anything.

No donut inside the neck...but did I mess something up? I know the case should grow when re-sized, assuming it's normal to push some thicker brass down into the neck...at what point, if ever do I turn them again to clean that thicker brass?

Is there a way to prevent what just happened?

 

[bigedp51]

According to the RCBS precision mic...the shoulders didnt bump back at all. From zero on the gauge, new the brass was .012 (reads .037) under the zero line (min saami), after first firing they expanded out .006-.007 inches and guage (now reads .043). The Redding body sizing die in my forster Co-Ax did not bump the shoulder from that .043 reading

My RCBS .308 Precision Mic reads minus .0025 with a GO gauge in it and my .223 Precision Mic reads minus .0065 with a GO gauge in it. Meaning these gauges are not calibrated so that zero is equal to a GO gauge.

And you may have had your resizing die set too low and pushed the shoulder back too far. And why the unturned section of the case shoulder is now part of the case neck.

 

[Deleted member 107666]

If the prec mic reading didnt change before or after the body die, doesnt that gauge just read the headspace, so if unchanged it didnt bump the shoulders?

I'm lost.

 

[antelopedundee]

My RCBS .308 Precision Mic reads minus .0025 with a GO gauge in it and my .223 Precision Mic reads minus .0065 with a GO gauge in it. Meaning these gauges are not calibrated so that zero is equal to a GO gauge.

And you may have had your resizing die set too low and pushed the shoulder back too far. And why the unturned section of the case shoulder is now part of the case neck.

Is it normal for a FL die to set the shoulder back that much or is there an issue with the chamber allowing it to move forward that much?

 

[antelopedundee]

No donut inside the neck...but did I mess something up? I know the case should grow when re-sized, assuming it's normal to push some thicker brass down into the neck...at what point, if ever do I turn them again to clean that thicker brass?

Is there a way to prevent what just happened?

Before you can prevent it it you have to know what caused it. Did the turned neck shoulder junction change when fired?

Does one really need the services of a body die after what I assume is one firing?

I'd take one of the sized cases and load it and seat the bullet so that it firmly touches the lands. This will keep it from moving in the chamber when the firing pin strikes. If the die is setting the shoulder back as suggested then the fired case will have the turn stop back at the neck shoulder junction as before. If the case looks the same as it does now then I'd just neck turn it like you did the first time. If you size the neck full length it looks like you will form the dreaded donut.

 

[Deleted member 107666]

My neck bushing does not size that far down.

I only body sized as I wanted everything to be uniform for load development and I had different pressure in those cases during searing depth test. Lesson learned on that.

I thought I watched a video from Broz where he uses that body die to bump shoulders .002 on every firing. But those redding shellholder he uses will not work with my Co-Ax...kinda lost on how to bump shoulders only.

I'm confident the shoulders didnt move on that sizing I did. So that leaves either the body sizing pushed the brass into the neck, or I just didnt cut deep enough with my beck turn. That is the worst of the cases I could find to make the issue obvious. The other cuts are still nice and close to the neck/shoulder junction

To add to the mystery, the case length did not grow during the body sizing.

 

[bigedp51]

Is it normal for a FL die to set the shoulder back that much or is there an issue with the chamber allowing it to move forward that much?

Chambers and dies vary in size and you are dealing with a belted case that headspaces on the belt and not its shoulder normally.

Example below is a new unfired rimmed British .303 case in a Wilson case gauge. This shows how short the shoulder is on a new case.

Below a fired .303 British in the Wilson case gauge resting on its shoulder. And this shows how much further forward the military Enfield chamber shoulder is located. And most belted and rimmed full length sizing dies will push the case shoulder back much further than needed.

Below a new unfired .303 British case on the left showin how short the shoulder location is. The middle case is once fired and the case on the right was full length resized and on the third firing the case had a partial case head separation.

Below rimmed and belted cases if reloaded should headspace on the shoulder to prevent case head separations.

Below another example of rimmed or belted cases below. Rimmed and belted cases dated from a age when cartridge manufacturing was not to the standards we have today. The case on the left is a newly manufactured .450 Martini–Henry and the case on the right was made in 1879. To put it bluntly rimmed and belted cases are outdated and from a time when manufacturing standards were very sloppy.

 

[Remmy700]

Zooming in on case u still got a little ways to go before u actually hit neck/shoulder junction with cutter. And yes body die makes your brass longer. No different than FL sizing as body gets sized back down the case has to go somewhere and it can't go down. As u mentioned your neck die don't go down that far as most do not but if u don't trim down to neck shoulder junction eventually it will expand and then the dreaded donut will appear brother. Or worst case u can use steel wool and polish that step a little.

 

[bigedp51]

My neck bushing does not size that far down.

I only body sized as I wanted everything to be uniform for load development and I had different pressure in those cases during searing depth test. Lesson learned on that.

I thought I watched a video from Broz where he uses that body die to bump shoulders .002 on every firing. But those redding shellholder he uses will not work with my Co-Ax...kinda lost on how to bump shoulders only.

I'm confident the shoulders didnt move on that sizing I did. So that leaves either the body sizing pushed the brass into the neck, or I just didnt cut deep enough with my beck turn. That is the worst of the cases I could find to make the issue obvious. The other cuts are still nice and close to the neck/shoulder junction

To add to the mystery, the case length did not grow during the body sizing.

My guess is that bushing dies do not size the entire neck to help keep any donuts from being sized down.

In the old days before gauges a .020 feeler gauge was set on top of the shell holder and then see if the case would chamber. If not then progressively thinner feeler gauges were used until the case would chamber with no bolt resistance closing.

 

[Deleted member 107666]

Zooming in on case u still got a little ways to go before u actually hit neck/shoulder junction with cutter. And yes body die makes your brass longer. No different than FL sizing as the box opens when it hit die it has to go somewhere and it can't go down. As u mentioned your neck die don't go down that far as most do not but if u don't trim down to neck shoulder junction eventually it will expand and then the dreaded donut will appear brother. Or worst case u can use steel wool and polish that step a little.

So turn again or I can let it be until it gets close to where my bushing sizes down to? Figure by the time it moves that far (almost 1/16 of an inch) the brass will he toast anyways?