Bushing Dies?

[Trickymissfit]

I'm sure with either that bad results mean we're doing something wrong. Afterall, somebody get's each approach to work..

I'm curious as to how a collet forces thickness variance outward. I mean on the surface it looks to me that the collet fingers are pushing(forcing brass) inward.
Now with bushing sizing(Wilson) I follow-up with mandrel expansion(Sinclair). This forces variance outward for me.

Also someone mentioned changing bushings for tension adjustment. This doesn't work. Tension = Springback, applied to area.
To adjust tension with a bushing die(to a pretty fine resolution), you can adjust the LENGTH of neck sizing.
Not sure that any of that could be done with collets.

your added step with a Wilson die is interesting. Never tried it, and really never thought much about it. I usually see runout of less than .001" TIR, and it would seem like the concept of running a sizer ball thru the case might circumvent the process. I'll try it to see what happens
gary

 

[rscott5028]

I'm sure with either that bad results mean we're doing something wrong. Afterall, somebody get's each approach to work..

I'm curious as to how a collet forces thickness variance outward. I mean on the surface it looks to me that the collet fingers are pushing(forcing brass) inward.
Now with bushing sizing(Wilson) I follow-up with mandrel expansion(Sinclair). This forces variance outward for me.

Also someone mentioned changing bushings for tension adjustment. This doesn't work. Tension = Springback, applied to area.
To adjust tension with a bushing die(to a pretty fine resolution), you can adjust the LENGTH of neck sizing.
Not sure that any of that could be done with collets.

Mike,

I mentioned neck tension and perhaps used the term improperly. What I meant was that I use my bushing to size down .002" less than the bullet diameter. I also adjust my die to size about half the neck.

I do this without an expander on fired cases that were neck turned before firing and get excellent concentricity/TIR inside and out on the necks as well as the bullets for what I believe to be reasonable and even neck tension.

I don't think you can get that granular with collet dies although there are some tricks I think. But, it's all relative and the collet system may be good enough for some of us. I haven't yet used Wilson dies, but that would be my next step up/over if I wasn't satisfied with Redding S-Type and the Forster co-ax press.

But, I'm have plenty to learn.

thanks,
richard

 

[Trickymissfit]

Mike,

I mentioned neck tension and perhaps used the term improperly. What I meant was that I use my bushing to size down .002" less than the bullet diameter. I also adjust my die to size about half the neck.

I do this without an expander on fired cases that were neck turned before firing and get excellent concentricity/TIR inside and out on the necks as well as the bullets for what I believe to be reasonable and even neck tension.

I don't think you can get that granular with collet dies although there are some tricks I think. But, it's all relative and the collet system may be good enough for some of us. I haven't yet used Wilson dies, but that would be my next step up/over if I wasn't satisfied with Redding S-Type and the Forster co-ax press.

But, I'm have plenty to learn.

thanks,
richard

right now I'm playing around with .0025" to .0035" tension on the bullets. Seems to show some promise, and SD's have improved a little bit. Now if it ever decides to stop raining I'll further these tests. Forster does sell sizing balls in different diameters, so that's also an option
gary

 

[rscott5028]

right now I'm playing around with .0025" to .0035" tension on the bullets. Seems to show some promise, and SD's have improved a little bit. Now if it ever decides to stop raining I'll further these tests. Forster does sell sizing balls in different diameters, so that's also an option
gary

I may try the precision ground K&M Expandiron Mandrels. I hear they're very good especially on new brass before neck turning.

I don't even use the expander when neck sizing fired brass with the proper bushing.

 

[Mikecr]

For partial neck sizing, you don't get anymore tension than springback provides to grip bullet bearing, no matter how undersize you go. And springback is 1-1.5thou (unless you're running WSSM brass at 20thou thickness). So leaving necks more than 1.5thou under (after springback) buys you nothing but tough seating and extra runout. And if you've over heated brass trying to 'anneal' it, you'll leave yourself even tougher seating AND less tension(because of reduced springback both directions).
There are somewhat recent threads that hashed this all out.
And full length neck sizing(the entire neck) changes this, but there is no good reason to ever do this.

The beauty of bushing sizing is that you can downsize no more than needed(excess is just that), AND adjust the length of downsizing to consistantly set best performing tension. Since you avoid excess cycling with this approach, 'annealing'(actually stress relieving), is rarely needed, so the tension you set is consistent -longer.

 

[rscott5028]

Mikecr - Thanks. I'll read up on it.

 

[rscott5028]

For partial neck sizing, you don't get anymore tension than springback provides to grip bullet bearing, no matter how undersize you go. And springback is 1-1.5thou (unless you're running WSSM brass at 20thou thickness). So leaving necks more than 1.5thou under (after springback) buys you nothing but tough seating and extra runout. And if you've over heated brass trying to 'anneal' it, you'll leave yourself even tougher seating AND less tension(because of reduced springback both directions).
There are somewhat recent threads that hashed this all out.
And full length neck sizing(the entire neck) changes this, but there is no good reason to ever do this.

The beauty of bushing sizing is that you can downsize no more than needed(excess is just that), AND adjust the length of downsizing to consistantly set best performing tension. Since you avoid excess cycling with this approach, 'annealing'(actually stress relieving), is rarely needed, so the tension you set is consistent -longer.

Mikecr,

So after re-reading your post and a couple of others, I should probably explain that I remove the expander and use a bushing calculated to leave my ID .002" undersize relative to the bulet OD not accounting for springback.

After resizing my next batch, I'll let them sit over night and measure the ID's. If I understand you correctly, they should settle out at around .0005" to .001" less than the bullet OD.

Is that about right?

Thanks,
Richard

 

[blanko]

Thanks for all the great information.

Do you guys ever have trouble with the bullets wanting to chamber with only using the lee collet neck sizing dies? Or around how many loads do you average before having to run the cartridge through a body die?

I was under the assumption I would be better off full length resizing for my hunting rounds.

 

[Mikecr]

I remove the expander and use a bushing calculated to leave my ID .002" undersize relative to the bulet OD not accounting for springback

Whenever you pull brass from a sizing die, it's going to immediately springback to counter your sizing. You can calculate it, predict it, & you'll see it.

Blanko, the number of cycles before shoulder bumping or body sizing is 'required' for good chambering, depends on cartridge design, your chamber tolerances, and your load pressures.
You might have to body size everytime, or never. Just have to measure & keep an eye on it.

 

[rscott5028]

Whenever you pull brass from a sizing die, it's going to immediately springback to counter your sizing. You can calculate it, predict it, & you'll see it.

Mikecr,

I understand that. But, I have also been told that some tiny amount of additional springback will occur overnight.

I may have misconstrued that or taken it out of context. So, I'll check that again. If that's even true, then it too is probably predictable as well.

Thanks!
Richard

 

[Trickymissfit]

I may try the precision ground K&M Expandiron Mandrels. I hear they're very good especially on new brass before neck turning.

I don't even use the expander when neck sizing fired brass with the proper bushing.

that's pretty much the system you use with a Wilson die. There is no expander, so it's very important that the neck O.D. be very round. I don't expand my neck I.D.s when turning necks, but that's just my method. I made several mandrels out of hardened A2 drill rod in different sizes. Ground them, and then polished them to get a light slip fit (A2 takes forever to polish!)
gary

 

[Mikecr]

Richard, you're right that brass continues to creep after taking energy.
It does so everywhere it took energy. Shoulders,, webs,, necks,, pockets.
It just won't be as much as it's immediate response.