Shoulder bumping technique

I'm neither but your the first one I've ever heard to expect a every single shell holder to be exact. Tooling wears so that's how tolerances change, I get it good machinist adjust but that's exactly why I buy bullets anymore with the same lot #
 
GLTaylor said:
Out of curiosity i just measured 3 different shell holders:
Lyman=.084
Redding= .122
RCBS=.121
Guess they do differ. That's why I originally bought several to have some adjustment room with my dies!?! 🤔
Click to expand...
It's the thickness at the base of the shell holder and the shell that varies. If you use the competition shell holders you must use the same shell holder when you set up your die if you are always switching between shell holders you will not get the same shoulder set back. I use redding shell holder and place the one I used to resize with in the box with the compitiion shell holders. I hope that I am making sense as to why this is important at least to me. If you watched videos that show the using of these shell holder they say the same thing.
 
milo-2 said:
I have typed 3 responses and deleted them, they may have been too advanced. Let's simplify.
First, new brass once fired historically across the board grows .004-.006" in length, once fired brass coming from your chamber does not all measure the same. So getting a real consistent bump after the first firing is hard because of that fact.
So you need a baseline number in conjunction of how fired brass fits back in your chamber. Typically I "Settle" on the bump first time, then fire brass the 2nd time and now is when the setting of the die becomes more critical.
As mentioned, a consistent lube is essential to your bump. Every lube works if done right, through trial and error, you will find one you trust. I don't want to go far on lubes, but people tend to point fingers when something goes wrong. Like blaming bad behavior on whiskey if you are a beer drinker and manage to get a big belly full of whiskey and now you have to answer for it. Whiskey and one shot bad, well, NO.
On the gap between die and shellholder, most likely flex, not slop in the press. The greater the gap, the less lube on the bottom of the case that needs it the most.
On turning the die down or up, threads are a 7/8 x 14 coarse thread, a minute turn is big. A tenth of a turn is way too much. One other thing you need to figure in is thread load between the die and lock ring when adjusting it, < Bear with me, If you want to back your die off some, you loosen the die from the press, back it off some to get some room to adjust the lock ring, now you will hold the ring down while backing the die out, pinch the 2, lock the ring, you need to the same when screwing it in also, you can't relax the load. That results in large changes.
With once fired Norma brass, you are a ways from any springback scenarios that you will encounter with more firings, You will learn as you as you go, like all of us, you are not national champ first time out of the gate. If I had known 34 yrs ago what I know today there would have been many less bumps in the road.
There are a lot of shooters in CA, try find a mentor, unless you are some type of social pariah, most people are willing to help.
Click to expand...
The instructions that came with my die says screw it down until it cams over. Do you know more than the die manufactures?
 
kdr74 said:
The instructions that came with my die says screw it down until it cams over. Do you know more than the die manufactures?
Click to expand...
Test for yourself. Measure a fired case with a comparator then size it Per the manufacturers instructions and see what it measures. I'd be interested in what you come up with
 
I've got dies that if I set them up to cam over a couple wouldnt bump at all, ALA shave the shell holder and I've got some it woul bump back right at crushing the shoulder.
 
Kdr,
Die manufacturers have to protect themselves. They (many) have to assume the person buying their dies is a beginner. If you adjust the die all the way down to the ram or cause cam over you are sizing your brass very heavily. Probably toward minimum Saami specs for the cartridge.
Some manufacturers ( if you read closely) suggest a different procedure for producing the most accurate cartridges. These instructions are directed towards more experienced/ accomplished handloaders, i.e. like competitive shooters/longdistance shooters.
For these shooters (like L Sherm was alluding to), you have to carefully measure everything to determine when you get to exactly what you want.
When an accomplished handloader finishes, he knows exactly how much he has sized his case, what his neck tension is and how much he has set the cartrige shoulder back.
This is all accomplished by precisely setting up your die to a specific cartridge. Each die/cartridge is likely different.
You Can just screw in each of your dies to the ram and go. The shells Will likely load and fire. Will you have gotten the best out of the cartridge and your rifle? Most assuredly not.
 
One thing I found to help is at the bottom of the resizing stroke I hold it down for a couple seconds it helps with spring back.
Click to expand...

We have gone as far as possible with sizing the case. I will not say 'spring back' is not a cute term but the case has a resistance to sizing.
L.Sherm said:
I'm neither but your the first one I've ever heard to expect a every single shell holder to be exact. Tooling wears so that's how tolerances change, I get it good machinist adjust but that's exactly why I buy bullets anymore with the same lot #
Click to expand...

A reloader should be able to measure the deck height of the shell holder; my shell holders have a deck height of .125".
 
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