Shoulder bumping

[Alpha1]

Until recently shoulder bumping was some thing I had read about but never put into practice. As I have stated in previous posts I have spent my shooting career shooting Milsurp rifles. A set of full length dies was all I needed and may be some expander dies for cast boolits.
Any way I am now neck sizing shoulder bumping and all sorts of weird and wonderful things.

Now that I am more familiar with the process and having acquired some very accurate measuring equipment I am puzzled/shocked by some of my results.
I have been messing with the caliber 6.5x55 swede a lot lately.
I have purchased a set of Redding competition shell holders. A couple of Redding body dies. A set of Redding full length sizing dies.
A set of Lee full length dies.
I threw all my 6.5x55 cases in the bin and invested in 100 new Lapua case all my testing was carried out with the new cases.
All measurements were taken using the Hornady over all lentgh gauge and the Hornady shoulder bump gauges.
The shooting sheds comparator and shoulder bump upper was used as a comparison.

I used once fired cases for the purpose of the exercise. I was shocked at the results. Everything was entered into a excel spread sheet.

The results for the Lee dies really opened my eyes.
I will post more results to morrow. I need to clean my guns and get them locked away.

[ovenpaa]

It will be interesting to see the spread sheet however you should expect differences in physical measurements between Hornady and our gauges as they are comparing distances using slightly different datums. I would expect readings to tighten up using SHED gauges.

[Alpha1]

I eventually settled on the Shooting Sheds gauges for measuring and discarded the Hornady ones. The Sheds are easier to use and in my opinion they give a more accurate reading.

The once fired case necks set back was fairly uniform at 1.767"

To start with and get a baseline a standard shell holder was used for all sizings.
A wamadet press was used for the testing.

The Redding full length sizing die set to just touch the shell holder set the shoulders back a average of 0.002"
The Redding body die set to just touch the shell holder set the shoulders back 0.009"
A second Redding body die used for comparison set to just touch the shell holder gave a different reading again.
A Lee full length die was then set to just touch the shell holder the Lee die set the shoulders back a huge 0.060. In fact the Lee die set the shoulders back so far that the extractor would not pick the case up. Im wondering if the die is faulty. I repeated the experiment and the Lee die was worse.
It is obvious to me that setting up the dies is important for consistent readings to be obtained. There is a difference in set back between the two redding body dies as well. One was purchased in the UK and the other one came from the States.

I have not used any of the competition shell holders yet. But the results are interesting I will continue populating my spread sheet and see how it goes. Out of interest I have started seperate sheets for some of my other firearms and will be recording my results.
I will probably need some more shoulder bump and cartridge over all length gauges. I have binned the Lee die it is either faulty or the shoulder set back is far to much for this rifle.

[The Gun Pimp]

No - the dies are NOT faulty. The purpose of your full-length sizing die is to allow YOU to re-size YOUR brass to fit YOUR chamber.

If you shorten the brass too much then that's YOUR fault - not the die's.

As I've said before - remove the firing-pin/spring assembly from the bolt and re-size your brass so the the bolt JUST kisses the case on closing.

What's hard about that? No need for gauges or anything else - your chamber is the only 'gauge' that matters.

[Alpha1]

The Lee die instructions tell you to screw the die in until it touches the shell holder. This die pushes the shoulder back to much if you do that. Im fully aware of the need to set the die up properly to achieve proper fit. But if I want to purchase gauges dies etc. Its my money and my time so I will. I will be using a body die and a L.E.Wilson neck die and a L.E.Wilson micrometer seating die for actually making my ammo because thats the way I want to do it.

[Sandgroper]

I have binned the Lee die it is either faulty or the shoulder set back is far to much for this rifle.

Don't bin it. Offer it up on the forum, I'm sure someone will take it - if not, I will.

[Alpha1]

This whole shoulder bumping exercise is just that a exercise a learning curve. I am an inquisitive person I like to learn about new things and I like shiny things especially stuff machined to tight tollences. I like to measure them and learn how they are made. Its what floats my boat. I shoot so I have empty cases to play with as I said before if I could not re load I would have no reason to shoot.

[Alpha1]

I had a rummage about and found another lee full length die. I repeated the test using this die the numbers came out as normal. It sized the cases to 1.767. This is measuring to the shoulder and is what I would expect the measurement to be. So the original die is faulty in my opinion. The original die is destined for the scrap bin I would not be happy passing it on to any one else.

[Whizzbang]

I had a Lee FL die which, when set-up as per the instructions, bumped the shoulder back 12 thou.

The instructions don't (didn't then) go into any detail about properly setting the die for correct head space.

[Alpha1]

This Lee die thing has been bothering me. I have Lee dies in lots of Calibers and I have never really had a problem with them before.
So I got the measuring tools out and spent some time examining the two dies side by side. I can not remember were I got the first set from but they will be a fairly recent acquisition. They are obviously second hand. The second set were in my loft among loads of other dies in different calibers that I no longer own.

The first set has been messed with there are machine marks on the die base and the entrance to the die has a lip and sharp edges the second die is a smooth honed finish which is typical of standard re loading dies. The first die is 0.060" shorter than the one I found in the loft.
Now that I have this information I could probably use the die. But we will see. Having proper measuring equipment and knowing how to use it certainly pays dividends regardless of what some people may think.
So that is that problem solved. Whats really annoying is I have probably goosed at least 10 once fired Lapua cases sorting this problem out. aaarggh

hmm whats next