Full-length resizing - differences between dies?

[MikeJ]

Laugh at me if you will, but I use Lee dies for all my reloading activities (.38/.357, .223, .308, 6.5, 7.92) and am pleased with the outcomes. However, over the past year I have been using the Hornady "Headspace Comparator Kit" as a means of adjusting the dies to give the cases a modest set back ("bump"?) rather than a full-on re-size in anticipation of the brass lasting a little longer - particularly for the 6.5CM.

However, taking a practical example of a number of Hornady cases, all fired several times and fresh out of the chamber at (using comparator insert 'C') 1.5575" I set the f/l die to size a case to 1.5570". When the case is chambered the bolt (with firing pin removed) drops quite happily under its own weight.

I then run the remainder of the cases through the die only to find that some are bumped back to 1.555" and some have "grown" to 1.5585" and are thus stiff to chamber.

Am I doing something so obviously wrong that I should never, ever be allowed near a reloading bench, or is it that the Lee f/l die is just unsuitable for this kind of thing?

 

[Pat Allen]

Once the FL die is set and solid it should size to 1/2 thou every time. Are you annealing your brass after firing ? If not it maybe that the case is springing back when released. Try holding the case in the die for 8-10 seconds to see if it keeps consistent size. Also make sure that you lube cases consistently as that can make a difference in my experience. Also try to size with consistent press speed. It maybe something else but if you try those simple steps it may help.

[MikeJ]

Thanks Pat - maybe it is a lack of annealing. It's something that I've never done, but I'll try keeping the pressure on for a while longer and see if that helps. I think that the lube is consistent. It's not a problem that I've had with .308 and .223 cases, so perhaps the 6.5CM brass is a little more sensitive to multiple firings and lack of annealing.

[Catch-22]

When measuring how much you’re bumping the shoulder, I see you’re using the technique of bolt drop.

Are you also removing the ejector pin & spring from your bolt too? 
Remember that even with the firing pin removed, the ejector will be pushing against the case head as the case enters the chamber…giving false readings.

[Catch-22]

And, are you measuring length of brass and trimming accordingly?

I remember once I forgot to trim before f/l sizing. I kept bumping my brass back and back, but still had issues with chambering. Essentially the end of the neck had stretched beyond the chamber…so making it hard to chamber. Nothing to do with the shoulder or body at all.

Once I’d remembered I needed to trim, it was all good…though the couple of cases I sized and sized again had been bumped too far and were scrapped.

[Catch-22]

Another thought, when f/l sizing, do you still have the expander ball in the die?

If so, as you size the case neck (for the 2nd time!) on the up stroke of the ram, some expanders ‘rip’ their way through the case neck and can elongate the neck a bit.

Ideally you should chuck the expander ball/rod in the bin and get yourself a dedicated expander mandrel die and calibre specific mandrel (which slips into the expander die). Not expensive (about £15 for the die, £10 per mandrel) but will stop over working the neck and will stop an expander ball ripping through the necks, stretching and distorting things horribly.

[MikeJ]

Hi Catch-22,

No, I'm not removing the ejector, and I'm trimming after f/l sizing. Not that there's much, if anything, to take off, but I'll trim first then size and see how that goes. As I mentioned above, it just seems to be an issue with the 6.5CM brass - perhaps I'm expecting too much from it!

Now, there's a thought about the expander......... something else to try! Thanks!

 

[Pat Allen]

I agree with catch 22 I never use the expander ball and mandrel after sizing 👍

[No i deer]

My forster 6.5x47 die still has the expander ball on it and I use a mandrel for neck tension..

Can't say over working the brass made any difference for me...

My brass did 15 firings before I scrapped it..

Nothing wrong with the necks... it was annealed regularly.

[Popsbengo]

2 hours ago, MikeJ said:

However, taking a practical example of a number of Hornady cases, all fired several times and fresh out of the chamber at (using comparator insert 'C') 1.5575" I set the f/l die to size a case to 1.5570". When the case is chambered the bolt (with firing pin removed) drops quite happily under its own weight.

I then run the remainder of the cases through the die only to find that some are bumped back to 1.555" and some have "grown" to 1.5585" and are thus stiff to chamber.

If I understand your data:  you're fire-formed case is 1.5575 and you want to bump back by half a thou ?  That's a very small bump.  I work to 2 thou bump for 6.5mm and .308.  If you can reliably measure 1/2 thou with a Hornady gauge I'm impressed especially if you're using a 1/2thou resolution caliper.

You have a variance of -2.5 and +1 thou.  Just to be certain I'd  check your measurement technique as it's quite easy to get an error with the Hornady gauging tool.  Clean the head and make sure there's no burrs etc.

If your cases are not chambering and are longer than the fire-formed case I think it's going to be your expander and/or overly springing brass due to hardening (as others have said)

[MikeJ]

Thanks Popsbengo,

The data may have been misleading - sorry. I should have mentioned that a fully-fireformed case comes out at 1.5585" and I was bumping back (or hoping to) 1.5570". Going back to 1.5565" might be more sensible. In my example I had quite a number of cases that were at 1.5575" after firing so used them initially. I think you, and others, in suggesting that either the expander or overly-springy brass (or both) might be correct in where the problem lies. I shall take all that on board and my next reloads will now be with new Hornady and Starline brass and I'll keep a careful eye on how they turn out after resizing. Too many variables with the old brass I think, as those cases had not all been shot the same number of times.

Thanks you all for your thoughts on the matter.

[Pat Allen]

Tbh I would stick with Lapua brass over Hornady or Starline. Also with creed keep to small primers as it lasts much longer. Annealing will help with life. I have Lap cases that have 20 odd firings and are still as good as new, but then again I do anneal after each firing.,

[Popsbengo]

17 minutes ago, MikeJ said:

Thanks Popsbengo,

The data may have been misleading - sorry. I should have mentioned that a fully-fireformed case comes out at 1.5585" and I was bumping back (or hoping to) 1.5570". Going back to 1.5565" might be more sensible. In my example I had quite a number of cases that were at 1.5575" after firing so used them initially. I think you, and others, in suggesting that either the expander or overly-springy brass (or both) might be correct in where the problem lies. I shall take all that on board and my next reloads will now be with new Hornady and Starline brass and I'll keep a careful eye on how they turn out after resizing. Too many variables with the old brass I think, as those cases had not all been shot the same number of times.

Thanks you all for your thoughts on the matter.

Ah!  Mixed brass (in terms of number of firings).  Not a good choice for precision reloading.

I've just checked my data:  Insert C  gives 1.555 ±2 for new virgin Lapua brass,  1.559 ±1 for Lapua fire-formed in my custom chamber.  I bump to 1.557 and accept any tiny variation on that.  It works quite well 😁

[Popsbengo]

Just now, Pat Allen said:

Tbh I would stick with Lapua brass over Hornady or Starline. Also with creed keep to small primers as it lasts much longer. Annealing will help with life. I have Lap cases that have 20 odd firings and are still as good as new, but then again I do anneal after each firing.,

+1 to that,  SRP Lapua should payback over its life

[Pat Allen]

Glad we are on same wavelength Pops 👍

[MikeJ]

Gents, thank you all very much for the helpful pointers, all of which have been taken on board! I'm in no position to get involved in any complex annealing process or have a machine to do it for me, but I will keep a more careful eye on number of firings of each batch of brass from now on. Nonetheless, although I'm probably never going to score successive V-bulls at 1000 yards at Bisley, the shots are close enough for me on the rare occasions that I get the chance to shoot at that distance. Clearly some room for improvement though!

[Popsbengo]

58 minutes ago, MikeJ said:

Gents, thank you all very much for the helpful pointers, all of which have been taken on board! I'm in no position to get involved in any complex annealing process or have a machine to do it for me, but I will keep a more careful eye on number of firings of each batch of brass from now on. Nonetheless, although I'm probably never going to score successive V-bulls at 1000 yards at Bisley, the shots are close enough for me on the rare occasions that I get the chance to shoot at that distance. Clearly some room for improvement though!

There are services that will do your annealing, added cost but maybe worth it on case-life with improved accuracy as an added benefit?

[MikeJ]

33 minutes ago, Popsbengo said:

There are services that will do your annealing, added cost but maybe worth it on case-life with improved accuracy as an added benefit?

I shall look into it Sir! I'm sitting here looking at eighty cleaned, resized (ha ha) and trimmed cases and was thinking about cracking on and reloading them but will put them to one side for the moment while I investigate annealing services.

[Geezedtee]

4 hours ago, Popsbengo said:

There are services that will do your annealing, added cost but maybe worth it on case-life with improved accuracy as an added benefit?

Is there one in particular you would recommend? I know Spud Reloading provide the service and I'm tempted to try him.

[Popsbengo]

19 minutes ago, Geezedtee said:

Is there one in particular you would recommend? I know Spud Reloading provide the service and I'm tempted to try him.

No, I have no experience of any as I do my own thing.  Judging from Mark's customer care at Spud, it would be one I'd try.

[MikeJ]

4 hours ago, Popsbengo said:

No, I have no experience of any as I do my own thing.  Judging from Mark's customer care at Spud, it would be one I'd try.

Well, I have just sent off 100 cases to Mark. We shall see. Meanwhile I'm looking at a Caselife annealer item (£179) or a Reloader Brass annealer (£220), the latter having a 6 week lead time. 

[Mattnall]

On 11/23/2021 at 4:51 PM, MikeJ said:

... I'm trimming after f/l sizing. Not that there's much, if anything, to take off, but I'll trim first then size and see how that goes.

Should you be trimming before sizing? What length are you going to trim to? As soon as you resize that will all change.

[MikeJ]

17 hours ago, Mattnall said:

Should you be trimming before sizing? What length are you going to trim to? As soon as you resize that will all change.

I'm trimming after resizing........ I really don't understand why there was a suggestion to trim before resizing 😕 

[Mattnall]

On 11/23/2021 at 4:51 PM, MikeJ said:

Hi Catch-22,

No, I'm not removing the ejector, and I'm trimming after f/l sizing. Not that there's much, if anything, to take off, but I'll trim first then size and see how that goes.

 

3 hours ago, MikeJ said:

I'm trimming after resizing........ I really don't understand why there was a suggestion to trim before resizing 😕 

I'm sorry, I saw you were doing it after but it was your suggestion that you were going to try it the other way, which was why I mentioned it.

[Richiew]

Bryan Litz's Modern Advancements in Long Range Shooting Vol II, Chapter on Neck Tension. Bryan ran some tests on .223 using an AMP annealer and measured effect on muzzle velocity consistency. His interim summary findings, pending more in depth study, was that their .223 data showed annealing didn't make any difference in muzzle velocity testing results. He points out there are good reasons other than SD/ES to anneal though.
The published findings from the book tend to run contrary to internet wisdom so I look forward to more in depth reloading research in a future Litz publication. For those who have not had a chance to read it though, the Vol II publication has 5 chapters in an advance handloading section that I found well worth reading through.

 

Reply This came from a US forum and I have also read his books. Was going to get an AMP and after reading the book thought I’d save my money and just reload until brass looks knackered then buy new . You can buy lots of brass for the price of an AMP . Cheers