Shoulder Bump Variance?

[ar15barrels]

Oh and for precision match reloads... do you think i'll notice a difference in accuracy with a .001 neck bump variance between brass?

no.

[HK Dave]

You will need to make shims or get the redding comp shell holders to hard bump.
Simply pushing the shoulders all the way down as far as your die will allow is only going to get you very consistently excessive headspace.

I do have the type S dies and some competition holders. Will try it again when I get a chance.

Your explanation makes a lot of sense with regards to the soft bump vs hard bump.

[LynnJr]

The only way to reduce the excessive bump is to re-fireform your brass using a false shoulder.Without doing that you are simply stretching your cases and making way for casehead separations down the road.
Once your brass has any clearance the bolt will drop.If you have 0.001 clearance or 0.035 clearance clearance is still clearance.

http://www.calguns.net/calgunforum/showthread.php?t=771381&page=2

Go to page 2 and click on the photos.
If your getting 0.005 variation your brass needs annealing or something is wrong with your press/die set-up.
More on thursday.

[LynnJr]

It's Thursday.

Did all of the brass come out of the same chamber?

Is it possible your load is not fully pushing the shoulder forward and the variance you are seeing is there before you size the brass?

If your press is flexing enough to give you 0.005 variance on cases that started out the same length with the same number of firings check the rams pivot to see if it is worn out or egg shaped.

0.005 variance is huge for shoulder bump.