FL shoulder bump question

[jimbires]

I struggled with this before . I have solved my problem . I got away from spray case lube . I went back to using RCBS case lube 2 on a lube pad . this helped a fair amount . next I bought a set of Redding competition shellholder . this fixed me up . my case measurements after sizing are very consistent . by using these shellholders the sizing die makes firm contact with the shellholder . making firm contact makes the brass go in the die the same amount every time . if you have the die raised up away from the shellholder , slipper brass will size more , softer brass will size more . I now have these shellholder sets for everything I load .

 

[TRexF16]

Try re-zeroing your caliper when you see your bump measurement start to drift, and nothing else in the process has changed.

 

[pdog shooter]

I've attributed that and several other inconsistencies to annealing. Might not be the answer but that's the one thing I haven't invested in and still do the redneck way.

 

[MagnumManiac]

I have found HOW you size is as much important as HOW you measure after sizing.
I hover at top dead centre. This lingering allows the brass to settle.
I measure with micrometers that are accurate to .0001".
I have blade type, ball type and normal type micrometers.
Calipers are for rough measuring at best.
I can measure my spring back to .0005" and final measurement to .0001" if needed, but rarely do as it is not necessary.
I also have have hardness testers, which tell me what range my annealing is giving me….is it necessary? Maybe not.

Cheers.

 

[Maol]

I bought a set of Redding competition shellholder . this fixed me up...

...I now have these shellholder sets for everything I load .

+1 for the Redding competition shellholders for each casehead family you load for.

I hover at top dead centre. This lingering allows the brass to settle.

Yep pause, also rotate and do'er again.

I rezero every time before I check for bump.

Consistent annealing matters too.

 

[cdherman]

Hey all,
I've been sizing my 2x fired hornady 6.5 prc brass and noticing some variance in my bumps. I meticulously set the shoulder bump to 1.644 and seem to get about 3-4 cases perfect then they start opening up from -.0005 to +.0015. Is this normal and/or a big deal or just roll with it? I'm using whidden bushing dies, RCBS rock chucker, and annealed after each firing prior to sizing.
Thanks

All the other posts are good, but one additional though if you are chasing the ultimate in repeatability is this.

If you are annealing, you are hopefully annealing evenly. But if there are occasional necks or shoulders that are softer or harder, you will get variation how much the bushing pushes the neck down in resizing. I am assuming that the Widden bushing dies do NOT have an expander ball? That's the other source of shoulder distortion. For dies that use expander balls, the ball can literally "pull" the neck back up during the expansion process.

Anyhow, just saying. Annealing and expander balls can introduce variation in shoulder too.

 

[Stammster2]

If you are depriming and resizing at the same time, you can also get some debris on the face of the shell holder that can change your bump.