A question about bumping the shoulder?

entoptics said:

I will add, that getting a consistent bump can be harder than it seems. You may need to take some material off the top of your shell holder, as the cam-over on your press may be tight enough to give inconsistent results.

I had this problem, and was getting variation of over 0.004". For 270 and 30-06 I sanded my shell holder down about 0.005". It still bumps the die when it's properly set, but not nearly as much. This improved my sizing precision to about 0.001".

I used a lathe at work to do the same for my 300WM, which also improved consistency.

It's also important to consistently lube your cases of course.

Click to expand...

Yes if you change the lube you use or the amount of lube that will give you unwanted change in the amount bump that you get.

Thank you orange dust, I shoot mainly a 338 edge and i have a two die redding set. These dies are not cheap so i quess i should cry now and buy a set of shawn carlocks dies and be done with it.

robert l said:

I think im missing some thing here. If you use a fl sizing die for bumping the shoulder back Then the case would have to go pretty much to full length to push the shoulder back? Or are we saying to 90 percent the way down the case and then check? Now i know every chamber is different. So you are pretty much resizing the whole case?

Click to expand...

Yes, sizing the whole case with a FL die. For most dies and shell holders, for "normal" chambers, the die will actually go all the way down to contacting the shell holder in order to go far enough for a shoulder bump. How hard it presses against the holder (cam-over) will get the last few thousandths necessary to set the shoulder back.

I usually start with the die just touching the holder, then proceed down in small increments, measuring each time, until I get the right setback. On all my dies, that's usually within about 1/8th turn from first die/holder contact.

whoa...some heat in this thread lol and rightly so it is important to understand headspace and how to do it.

Having said that and instead of trying to explaining it myself. I will say look up pan handle precision. I am sure some of us have watched Sam's videos' he has great youtube videos on this subject and how to use the redding competition shell holder set to set shoulder bump.

If you look closely he has a whole reloading segment I think its like 8 or 9 parts. In my opinion its the best content on youtube on how to reload. No kidding, it's really that good and well put together.

In fact I have contacted him myself and if it's not answered in his comments section he normally will get back to you directly.

Well now I am royally confused I thought shouder bumping saved work on our brass. To me this sounds like the old process that was hard on our brass. It sounds like just the way every die company tells us to set up our dies. My belief now is I should look at the Forester shoulder bump neck die. Am I missing some thing or just stepping back to where I started. That is with FL shoulder bump method.

WildBillG said:

Well now I am royally confused I thought shouder bumping saved work on our brass. To me this sounds like the old process that was hard on our brass. It sounds like just the way every die company tells us to set up our dies. My belief now is I should look at the Forester shoulder bump neck die. Am I missing some thing or just stepping back to where I started. That is with FL shoulder bump method.

Click to expand...

yes but it also allows you to set your shoulder back from a fired piece of brass for a custom fit in your chamber----just enough so you don't get a case stuck if you get some debris in the chamber ie sand, dust, blade of grass etc. In a bolt guns guys normally use a 2 thou ish bump in auto's and pumps more like 5 thou

I myself use Redding competition shell holder set and incrementally use the various thicknesses to reach my shoulder bump. This way once my die is set I only have to place the exact shell holder I previously used to bump the fired brass but of course if you change brass than you have to redo the process.

All of this is true but it is a pile garbage that we are not working our brass as much. I used to set my FL die a quarter of a turn or more off the the shell holder and it still was hard on the brass. Could some one tell me how this process is easier on our bras then neck sizing.

It is not. I use a forster neck die with a shoulder bump.

I set up a fl die completely differently if not using a neck die most of the time and just fl in a bolt action. I start with the die about 1/8" off the shell holder, and lower the die until the case will just chamber with some resistance. They call this partial resizing. Whole point of this is not to streach the case just above the web.

WildBillG said:

All of this is true but it is a pile garbage that we are not working our brass as much. I used to set my FL die a quarter of a turn or more off the the shell holder and it still was hard on the brass. Could some one tell me how this process is easier on our bras then neck sizing.

Click to expand...

WildBill G, I see your point and what I'll say is yes you [are or do] have to work your brass somewhat I mean we are FL sizing after all right? I still have to put my ram in the uppermost position on my press and screw my die body down till it touches then a slight turn more for just a touch of cam over ...BUT I am starting with the shell holder marked .010 not the standard shell holder and then if I don't get the 2 thou bump I'm looking for I try the .008 then .006 .004 and lastly .002 somewhere in there I will see my 2 thou bump I am looking for. Hope this helps. The end state, is as we all know, is brass that is just a touch smaller than fired but sized only enough to allow for easy removal in all field conditions.

If I was running a bench rest gun then I might only neck size my brass. In fact I know a few hunters that only neck size and get great results but will have on occasion a piece of brass that does not chamber smoothly or may get stuck during extraction after firing - not much of an issue at the range but in the field I'd think that is a bad situation without a cleaning rod around so I FL size and bump my shoulders.

WildBillG said:

Well now I am royally confused I thought shouder bumping saved work on our brass. To me this sounds like the old process that was hard on our brass. It sounds like just the way every die company tells us to set up our dies. My belief now is I should look at the Forester shoulder bump neck die. Am I missing some thing or just stepping back to where I started. That is with FL shoulder bump method.

Click to expand...

Bingo stepping back sounds right to me.

I agree with you Orange Dust about the neck shoulder bump die. 2C I get and understand what you are saying. My point is that I have been reading that shoulder bumping worked our brass less or no more then neck sizing. I my self have been neck sizing now for 30 some years with out an issue. Yes no one else can use my ammo which may or may not be a plus. From what I under stand now basically any one with a bolt gun could chamber my shoulder bumped ammo. Which also leads me to believe this far less then custom ammo to my chamber. Now I under stand that seating depths may vary but a hot load just nudging into the lands of anothers rifle could be bad news for them. My thoughts are I should seriously look into the Forester neck size shoulder bump dies and gain the best of both worlds. A bonus of the Forester die is they come with 3 bushings included.

WildBillG said:

...I have been reading that shoulder bumping worked our brass less or no more then neck sizing...From what I under stand now basically any one with a bolt gun could chamber my shoulder bumped ammo. Which also leads me to believe this far less then custom ammo to my chamber. Now I under stand that seating depths may vary but a hot load just nudging into the lands of anothers rifle could be bad news for them. My thoughts are I should seriously look into the Forester neck size shoulder bump dies and gain the best of both worlds...

Click to expand...

I think you are misunderstanding a little. This may get a little long winded, but I'll try and clear up all your concerns, as best I can. The short answer, is you don't need special dies, and there is no "best of both worlds".

1) Blindly following die instructions "touch the shell holder, then add 1/8 turn" or whatever, will almost certainly bump the shoulder a bunch more than necessary. My OEM Savage barrel had ~0.01" more headspace than my current Shilen barrel, and more than any other rifle I have measured. I'm pretty sure it was out of SAAMI spec. Before I really understood that, I was following die instructions, and probably bumping the shoulder at least 0.015" every reload. Case head separations occurred at 3-4 firings...

2) As above, bumping the shoulder 0.002" from fired, in no way means the brass will now chamber in every gun. My OEM Savage would eat neck sized only brass from any gun, as it's chamber was incredibly long (I proved this with 2 friends' guns once fired brass). If I'd known back then to FL size and bump the shoulder 0.002", my ammo CERTAINLY still wouldn't fit in most guns (even my buddies identical Savage LRH had 0.005" less clearance).

3) From rifle to rifle, shoulder position variation has far less affect than throat length, when it comes to "touching the lands". My buddy's identical rifle had a 0.02" difference in throat, but only 0.005" in shoulder. I've measured 3 different 30-06 rifles, and they had a whopping 0.13" extreme spread in base-to-ogive for the same projectiles. It is unlikely you'll run into "jammed bullets" simply due to headspace. For example, the two 30-06 mentioned above, I could have run the bullets 0.1" off the lands in the Rem700, and it would have jammed the bullet in the Win M70 anyway. The difference in headspace (base to shoulder) between the two rifles is about 0.002". If I wanted to run brass for both of them, I'd bump them to the shortest of the two, but I'd still have to deal with huge difference in bullet jump.

4) "Best of both worlds" doesn't really exist (see 30-06 examples above). If you want reliable ammo that will feed in any gun, build it right at max SAAMI specs (like factory ammo is), for both shoulder position (headspace), and base to bullet ogive. If you do that, it will almost assuredly reduce brass life, due to excessive chamber clearance, allowing the brass to expand far more than necessary, and then be resized back down more than necessary. It will also be loose in almost all chambers, with highly variable bullet jump, and therefore not provide the best precision possible.

5) Any die, machined to proper specifications, will allow you to do the minimum necessary sizing for a chamber machined to proper specifications. Measure your fired brass, seat the die deep enough to only move the shoulder back a couple thousandths, and you're good to go for that particular rifle.

6) It is my understanding, that a thousandth or two clearance in all directions/areas (properly FL sized) will actually result in better precision (let alone reliability), than brass that snuggly fits the chamber (neck sized). If the cartridge rubs/jams/etc in any area, this can actually result in more misalignment variation than having it sit freely on the bottom of the chamber. I don't have any real data to back that up, but it does seem logical...

Hope that helps.

WildBillG said:

I agree with you Orange Dust about the neck shoulder bump die. 2C I get and understand what you are saying. My point is that I have been reading that shoulder bumping worked our brass less or no more then neck sizing. I my self have been neck sizing now for 30 some years with out an issue. Yes no one else can use my ammo which may or may not be a plus. From what I under stand now basically any one with a bolt gun could chamber my shoulder bumped ammo. Which also leads me to believe this far less then custom ammo to my chamber. Now I under stand that seating depths may vary but a hot load just nudging into the lands of anothers rifle could be bad news for them. My thoughts are I should seriously look into the Forester neck size shoulder bump dies and gain the best of both worlds. A bonus of the Forester die is they come with 3 bushings included.

Click to expand...

Yes, but there is no free lunch. You can induce some runout to your ammo with this. This is due to not supporting the case walls completey sizing the neck and shoulder. It can be minimized with skim turned necks and oversizinz the necks just a tad, then using a neck expanding die. The least runout you can do on a press is with fl dies without the expander button and expanding the necks separately. Then using a benchrest seater. You cannot shoot consistent ting groups without pretty straight ammo. Neck sized brass will last longer if not max pressure. In hot magnums usually the primer pocket loosens before the brass wears out with either method anyway. I fl size for hunting.