• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Inconsistent shoulder bump

M

m1ajunkie

Full Member
Supporter
Full Member
Minuteman
Feb 22, 2010
1,048
226
35
Kennewick, WA
I've been fighting an issue with my .308 resize process that I'm hoping someone can help me address. I'm using Federal .308 brass that's been fired multiple times, I'd estimate 4-6 firings and I don't anneal. I'm using a Redding full length sizing die with expander ball. This problem is not something that's recent but rather something I've been fighting for a long time.... I'm just tired of it now.

When trying to set my shoulder bump I'm unable to get any consistency out of my bump. Fired cases measure 1.622 on the hornady comparator and I'm targeting a bump of 1.620.

Whenever I run my brass through my sizing die I end up with shoulder bump variance of .005-.006. Meaning some will come out with zero bump at 1.622, then the very next case will come out at 1.616. Then I'll get a handful in the 1.618-1.621 range which I accept as usable resized cases.

What am I missing here?

On my 6.5CM, 6CM, & 300 PRC setup I can get much better consistency so the problem is isolated to my .308 setup and I can't figure it out.
 
Assuming you don't get a good answer later, If you want to go through the effort, you can mail me a handful of cases with a return label, I'll anneal with my AMP for you. If they bump correctly after, then you know that was it.
 
  • Like
Reactions: colorado_native, MCHOG and m1ajunkie
918v said:
Inconsistent lube, press linkage slop, etc.

I use Redding competition shell holders and stop the ram’s movement on the die. That way I eliminate any issues related to linkage or press springing.
Click to expand...
This right here. If you want consistent bump, the top of the shell holder must come in contact with the bottom of the die to serve as a positive mechanical stop. You will just be pissing in the wind by just screwing your die up or down for a target bump value. Invest in the Redding competition shell holders and start getting your shoulder bumps +/- .001" or better every time regardless of case lube or press flex.

I bump shoulders with a Redding body die and size necks in a separate step with my Lee Collet Die. Most of my Redding body dies usually team up best with a +.008" competition shell holder for about a .002" shoulder bump in all my chambers.
 
gigamortis said:
This right here. If you want consistent bump, the top of the shell holder must come in contact with the bottom of the die to serve as a positive mechanical stop. You will just be pissing in the wind by just screwing your die up or down for a target bump value. Invest in the Redding competition shell holders and start getting your shoulder bumps +/- .001" or better every time regardless of case lube or press flex.

I bump shoulders with a Redding body die and size necks in a separate step with my Lee Collet Die. Most of my Redding body dies usually team up best with a +.008" competition shell holder for about a .002" shoulder bump in all my chambers.
Click to expand...

I'm convinced. Going to see if I can order up some competition shell holders and see if that doesn't help me out.
 
If you are using a Lee press that is your problem most likely. I had this issue and found that Lee’s linkage arms are really cheap MIM parts and will develop a hairline crack in places. This gives enough play to cause inconsistent resizing.
If you have a friend run some through his press with your dies and see if that fixes it.
 
Early on I had this problem and yes it is frustrating. Amount of lube (Imperial Case Resizing Lube) was a contributor. Paid more attenttion when applying which helped. Still too much variation. Next I tried the competition shell holders. Again, more improvement, but not a good enough solution. Finally, I went to PMA Micro Die Adjuster. When Istarted a resizing evolution, I measured the resized brass and then fine tuned with the adjuster. This gave me infinate flexibility when resizing different brands and ages of my brass.
Problem solved for me.


1616668850713.png
 
  • Like
Reactions: Dogtown
m1ajunkie said:
I'm convinced. Going to see if I can order up some competition shell holders and see if that doesn't help me out.
Click to expand...
You don’t need to waste 60 bucks on a shell holder.
I don’t use any shell holders and I don’t have that issue.

I’m putting my money on untracked, random higher number of firings on unannealed, shitty federal brass.
 
Last edited:
  • Like
Reactions: Edgecrusher, orkan, NH4X and 3 others
My two observations are:
  1. You should increase or decrease bump with the shell-holder size ... not the press under/over-cam
  2. Expecting 6x-fired brass to mold properly without annealing is really a stretch (no pun intended)
 
  • Haha
Reactions: ACard
I've found that different lots (same brand) can cause significant differences in bump. I proved this to myself a few days ago when I sized a box full of same brand brass of mixed lots for a friend. Some bumped back perfectly and some were .003 different. Upon closer inspection, I could see the headstamp print was slightly different - 3 variants. Also, lower end brass will tend to have bigger differences in metallurgy even in the same lot and can also cause inconsistent bumping. Just my .02...
 
5-6 firings with no annealing is your problem IMHO.

I anneal after every 3rd firing and get very consistent results afterwards and again after the 1st firing. After the 2nd firing, I get slightly less consistent results and that's when I decided to start annealing - I didn't even check to see how much more inconsistent they got after the 3rd firing.
 
I've been on the fence about starting to anneal and these responses are making a case for it. If I'm going to spend money, the annealer is something I'd rather spend money on.

From what I'm seeing the Giraud Annealer is a solid unit? Any others I should be looking at instead?
 
I AMP anneal *every* firing and still have difficulty maintaining absolute bumping with a CoAx. There are too many variables to expect absolute +- .001, IMO.
 
Last edited:
  • Like
Reactions: Vengeful1 and m1ajunkie
How do you determine what is acceptable play in a reloading press? I have a Rockchucker and a 550B, both of which have some miles on them but have been very well maintained. I can detect play if I push the ram with my hands to deflect it. I seem to struggle with the shoulder bump consistency too and I anneal after each firing. thanks
 
m1ajunkie said:
I've been on the fence about starting to anneal and these responses are making a case for it. If I'm going to spend money, the annealer is something I'd rather spend money on.

From what I'm seeing the Giraud Annealer is a solid unit? Any others I should be looking at instead?
Click to expand...
I've had a Giraud for about 6 years and they are solid and trouble free. There are some quirks to deal with but nothing monumental and nothing that hasn't been well documented on the www.
Induction as the heat source is a definite plus (mine is torch) but as with everything it comes with a price.
 
Gregor.Samsa said:
How do you determine what is acceptable play in a reloading press? I have a Rockchucker and a 550B, both of which have some miles on them but have been very well maintained. I can detect play if I push the ram with my hands to deflect it. I seem to struggle with the shoulder bump consistency too and I anneal after each firing. thanks
Click to expand...

Would like to know the answer to this as well. The thing I cant figure out is I use the same press to load my other calibers and I only have the inconsistencies with my .308 brass.
 
Gregor.Samsa said:
How do you determine what is acceptable play in a reloading press? I have a Rockchucker and a 550B, both of which have some miles on them but have been very well maintained. I can detect play if I push the ram with my hands to deflect it. I seem to struggle with the shoulder bump consistency too and I anneal after each firing. thanks
Click to expand...

Wait... you anneal and still have inconsistent shoulder bump? How can that be?
 
FWIW I am using a Co-Ax with redding comp dies and lapua cases (.308) and was/am having same inconsistencies your seeing.
I had 3 firings on my brass and was using a old turret press before I got the coax. After the coax I also annealed with the annealez and it seemed to be more consistent... I will be testing after this next firing with adjusting my anneal process
 
If your brass doesn't have the same hardness, it won't have the same spring back. Even with the same lots, hardness can vary and you could have slight differences. Anneal and set dies to achieve middle of the road results. A thousandth or two high and a thousandth or two low is about the best you can expect.
 
  • Like
Reactions: NH4X, 2aBaC̶a̶ and spife7980
All acceptable replies, surprised no one has mentioned checking your calipers. Incapable or inconsistent method of measurement may be driving you unnecessarily.
 
  • Like
Reactions: spife7980
Halfnutz said:
All acceptable replies, surprised no one has mentioned checking your calipers. Incapable or inconsistent method of measurement may be driving you unnecessarily.
Click to expand...
Funny you mention calipers, I actually recently purchased a second caliper just for this purpose. Same readings on both sets of calipers.

Really appreciate the help in this thread. I understand there will be some variance in shoulder bump but what I'm seeing with my .308 is not inline with the other calibers I'm loading so I know I'm missing something.
 
  • Like
Reactions: Halfnutz
918v said:
Wait... you anneal and still have inconsistent shoulder bump? How can that be?
Click to expand...
That's what I'm wondering myself. possibly over-lubing? I've been spraing with alcohol / lanolin concoction. I'll dial that back. calipers are Mitutoyo. sorry if I'm hijacking, just have the same issue as OP.
 
  • Like
Reactions: m1ajunkie
But these people are blaming all of this on shoulder hardness. Yet your problem persists despite your shoulders having been annealed. Hmmm....

The easiest thing to do is to set up your sizer die to stop hard against the shell holder. Competition shell holders make precise shoulder bumping super easy.
 
  • Like
Reactions: Edgecrusher and Gregor.Samsa
918v said:
But these people are blaming all of this on shoulder hardness. Yet your problem persists despite your shoulders having been annealed. Hmmm....
Click to expand...
Where do you see that they have been annealed?

Edit: NVM, you werent replying to the OP.
 
Last edited:
spife7980 said:
You don’t need to waste 60 bucks on a shell holder.
I don’t use any shell holders and I don’t have that issue.

I’m putting my money on untracked, random higher number of firings on unannealed, shitty federal brass.
Click to expand...

^^^^^
I'll also add in that some people live life in a hurry.
If I'm making blasting ammo, speed is everything.
Ammo for accuracy gets a different treatment with a noticeable one being that I slow down my sizing process.
I size more slowly and I also pause for a full two seconds at the top of the stroke.

My measurements are way more consistent than with the speedy sizing, even without annealing.
 
  • Like
Reactions: netcat and NH4X
You don't need those Redding competition shell holders.

Ditch that caveman expander ball and get a mandrel like a civilized human.

Annealing is real, ignore the naysayers, it's science. Bust out a drill, torch, and timer and find out for yourself.

If it's still fucked up, should have probably stopped shooting .308 by now anyways lol.
 
Mike Casselton said:
^^^^^
I'll also add in that some people live life in a hurry.
If I'm making blasting ammo, speed is everything.
Ammo for accuracy gets a different treatment with a noticeable one being that I slow down my sizing process.
I size more slowly and I also pause for a full two seconds at the top of the stroke.

My measurements are way more consistent than with the speedy sizing, even without annealing.
Click to expand...
+1
I load on a Rockchucker and a Co-ax, and my numbers became more consistent when I started pausing at the top of the stroke. Helps on freshly annealed as well as 2-3x fired.
 
I was litterally dealing with this exact thing last night in my My 6.5 CM. Thinking I can skip annealing and just size a bunch of random brass. I chased my die up and down trying to get it consistent.

Annealing and spring back is real. You could probably separate your cases into groups of how many times fired just by how much each cases sizes.

If you set your die up using a softer case it wont size the harder ones. To get the harder ones to size you will have to screw down the die past what you want the actual headspace so when it springs back its there. Then when you size a soft one it stays at oversized because theres no spring back.

I took cases that wouldnt size, annealed them and magically they all sized consistent.

At that point i said fuck it and annealed everything. If you have a drill, a deep socket, and a torch you can test it yourself.
 
  • Like
Reactions: CK1.0
I size 6x fired brass and they are all within a thou of one another... without annealing. People who need to anneal in order to size their brass consistently are doing it wrong.
 
  • Haha
Reactions: 2aBaC̶a̶
When you use imperial sizing wax and Redding competition shell holders then you can replicate my results.
 
@ O P..........Think about it........308 is the only problem child......so ,put the shell holder ,anneal ,use mandrel advice to the side .

IMO ,you have a brass problem ( 4-6 firings ).....don't mix them, And / or an expander ball issue......hinted above. Pull that expander out and give it a good polish.......and while its out , size a few cases to see if bump is the same..........dwell time ,as Mike mentioned above is your friend.......I'm a 5 count guy .

May be time to set that batch of brass to the side and start with fresh known brass of diff. manufacture.......if you can find any
 
  • Like
Reactions: m1ajunkie
918v said:
Have you ever used Redding competition shell holders? Do you know how they work?
Click to expand...
I am aware of how they work but my press doesn't take shell holders so no I haven't actually used them. Guess my reloads can never be as good as yours.
 
  • Like
Reactions: jmw
I sized some more brass last night and noticed the bump gradually increasing and I am 99% sure at this point that it's attributed to lube accumulation at the shoulder area of the die. It totally makse sense as that the only place for the lube to be displaced when sizing the casings. I am going to dilute my lanolin mixture with more alcohol. I love imperial sizing wax but handling each shell one by one takes up a lot of time that i do not have. Very good info in this thread.
 
Solid replies in here. For what it's worth, I rounded up some 1x fired FC cases yesterday and ran them through my setup. Shoulder bump was much more consistent, variance of maybe .002-.003 which I can live with...... at this point I'm convinced annealing should help and plan to purchase an annealer.
 
Interesting replies here. I hold my own opinions...

I'll simply say that my shoulder bump uniformity is not specifically reliant on annealing, as I can achieve consistent bump across more than 2 dozen firings without annealing. I use a Forster Co-Ax, and my dies do NOT touch the shell holder/jaws. Uniformity is also not reliant on whether I use a forster, whidden, redding, SAC, or any other die, nor is it reliant on using/not using any of the expanders for those dies. (as long as those dies are in positive working condition)

The most significant factors in shoulder bump uniformity would seem to me to be the press, and whether it has a firm mechanical stop that is not a function of the ram/shell holder hitting the die. (because I service dozens of dies, and don't feel like buying 10 precision shell holders of different heights for every single bolt face I load for** see wildcats with very custom chambers) The friction uniformity relationship between the die, the brass, and the uniformity of the lubrication used.
 
  • Like
Reactions: kthomas, 2aBaC̶a̶ and NH4X
orkan said:
I use a Forster Co-Ax, and my dies do NOT touch the shell holder/jaws.
Click to expand...

orkan said:
not reliant on whether I use a forster, whidden, redding, SAC, or any other die,
Click to expand...

Well I’d like to know the magic behind your process.

I AMP anneal Peterson brass every firing, use a Forster press, lube lightly with Redding die wax and size with Whidden dies - there’s no way I can bump the shoulders *without* dialing a bit past plate touch. (Actually a slight cam over) I can hold +- 001 for some, but invariably there will be the overbumped .003.

Seriously, I’m set up as you describe, what’s your secret?
 
DellaDog said:
Well I’d like to know the magic behind your process.

I AMP anneal Peterson brass every firing, use a Forster press, lube lightly with Redding die wax and size with Whidden dies - there’s no way I can bump the shoulders *without* dialing a bit past plate touch. (Actually a slight cam over) I can hold +- 001 for some, but invariably there will be the overbumped .003.

Seriously, I’m set up as you describe, what’s your secret?
Click to expand...
You setting up shoulder bump on a 3x+ fired case?
 
You must log in or register to reply here.

Similar threads

Y
Once fired brass and shoulder bump
Replies
14
Views
733
Dolomite
D
A
Question on resizing with SAC die
Replies
29
Views
542
B y r o n
B y r o n
N
Shoulder bumping for a short spec’d chamber.
Replies
6
Views
170
Rio Precision Gunworks
Rio Precision Gunworks
T
Line on case below shoulder
Replies
10
Views
257
Tmm01
T
D
Help Requested: Random Rounds won't chamber
Replies
27
Views
440
918v
918v
Top Bottom
Back