Yet another shoulder bump question

[marine52]

If you read DLT’s (OP) posts, he is concerned with an inconsistent bump. He has a .010” gap between the shellholder and die when he hits his optimal base-to-datum point of 1.448 to 1.449. It was suggested by several others that he should use the Redding comp Shellholders to get a firm die-to-shellholder contact (or camover if you please) This normally leads to a more consistent bump. Area 419‘s modular shellholder system does the same thing.

Skip’s shims are a fast and precise way of adjusting your die without having to unlock the lock ring. They do not change the bump measurement given you have a hard contact between die and shellholder.

 

[K22]

Skip’s shims are a fast and precise way of adjusting your die without having to unlock the lock ring. They do not change the bump measurement given you have a hard contact between die and shellholder.

With all due respect, this is NOT true.

If the FL die is setup* with the .010 shim, then replacing the .010 shim with the thinner shims, i.e., .008 to .003 increases the bump. I've been doing this for many years now. I had no problem whatever ever obtaining any desired bump I need by inserting the appropriate shim under the lock ring.

*See my early post on setting up the FL die with the .010 shim.

 

[DShortt]

If you set your die to be in hard contact with the shell holder it can not go any closer to the shell holder.
If you add shims under the lock ring you can DECREASE the amount of shoulder set back but not INCREASE the amount of setback.
If you set your die up with a .010" shim under it and have hard contact with the shell holder then removing the .010" shim and installing a .008" shim can not increase the amount of shoulder set back. If you're doing that and your shoulder set back is changing it's simply because you sized the brass a second time and has nothing to do with the shim thickness.

 

[K22]

If you set your die to be in hard contact with the shell holder it can not go any closer to the shell holder.
If you add shims under the lock ring you can DECREASE the amount of shoulder set back but not INCREASE the amount of setback.
If you set your die up with a .010" shim under it and have hard contact with the shell holder then removing the .010" shim and installing a .008" shim can not increase the amount of shoulder set back. If you're doing that and your shoulder set back is changing it's simply because you sized the brass a second time and has nothing to do with the shim thickness.

We are pissing in the wind. I DO NOT size the cases a second time.

The FL die is set up with the .010 shim. By replacing that shim with a thinner shim, it moves the die down increasing the sizing.

I run the case through the FL die only once. Unless my bump gauge and caliper are lying, I'm bumping the shoulder back, the degree depends on the shim I'm using. It has everything to do with the shim thickness. I can create anywhere from a zero bump to a .004 bump simply by replacing the shim.

I've done this thousands of times. I verify the bump every time I size a group of cases with a bump gauge and caliper.

Have you ever used them?

 

[243winxb]

a hornady set I bought first for this rifle acts like the neck is going to get ripped off the case.

Brass comes with a donut at neck shoulder junction on most all 223/5.56 brands. Some worse then others. Over working the necks will result in splits or separations.
A bushing die or neck turning reduces the effect to pull an expander up out of the case. Lube inside of neck.

Press linkage makes the variation when shoulder bumping. Normal .

 

[DShortt]

We are pissing in the wind. I DO NOT size the cases a second time.

The FL die is set up with the .010 shim. By replacing that shim with a thinner shim, it moves the die down increasing the sizing.

I run the case through the FL die only once. Unless my bump gauge and caliper are lying, I'm bumping the shoulder back, the degree depends on the shim I'm using. It has everything to do with the shim thickness. I can create anywhere from a zero bump to a .004 bump simply by replacing the shim.

I've done this thousands of times. I verify the bump every time I size a group of cases with a bump gauge and caliper.

Have you ever used them?

I don't use them because I set my dies differently and have no need for them.
I have been thinking about this and there is a possible explanation. If you initially set your die to hard contact with the shell holder and lock the lock ring then remove it, add a .010" shim and then begin adjusting the shims to achieve the shoulder measurement you are looking for then THAT would make sense.
If that is what you do then either I missed it or it wasn't explained that way. If it was me then I apologize.

 

[Ccrider]

Posts like this further reinforce my investment into the area 419 zero press and shellholders.

I like nice toys too. I can hold about the same level of accuracy with my Lee press and custom dies. I can also induce .001 variance with lube or not pulling the ram consistently. (Something sounds wrong about that-pulling the ram???)

The op is complaining about .001 variance in shoulder length, and he is annealing with a torch?

My suggestion is to bump all shoulders to give a minimum .002 clearance. If you have a stubborn piece, adjust the die or spin the case in the holder a half turn and size it again. No big deal. I can give several other things that I have found can cause variations on sizing but will not.

Be more concerned with whether that stubborn piece hits where it should on the target. If it does not, chunk it and move on.

 

[K22]

I don't use them because I set my dies differently and have no need for them.
I have been thinking about this and there is a possible explanation. If you initially set your die to hard contact with the shell holder and lock the lock ring then remove it, add a .010" shim and then begin adjusting the shims to achieve the shoulder measurement you are looking for then THAT would make sense.
If that is what you do then either I missed it or it wasn't explained that way. If it was me then I apologize.

No need to apologize.

The .010 shim setup provides the baseline. By replacing the .010 shim with a thinner shim the sizing is increased since you are reducing the distance between the shell holder and the die. It is sort of the same principle as competition shell holders.

I've been doing it this way for a very long time. For me, this process is easier to control bump than other methods. I'm not saying it's better, it's just easier for me, and a lot cheaper I may add. I merely offered the idea to the OP as an economical alternative to competition shell holders. The shim set can be used with any 7/8" sizing die.

 

[DShortt]

No need to apologize.

The .010 shim setup provides the baseline. By replacing the .010 shim with a thinner shim the sizing is increased since you are reducing the distance between the shell holder and the die. It is sort of the same principle as competition shell holders.

I've been doing it this way for a very long time. For me, this process is easier to control bump than other methods. I'm not saying it's better, it's just easier for me, and a lot cheaper I may add. I merely offered the idea to the OP as an economical alternative to competition shell holders. The shim set can be used with any 7/8" sizing die.

OK, you have said the exact same thing several times but I still don't understand specifically how the die is set in relation to the shell holder, when you tighten down the lock ring and when the shims are installed.

I *think* I know how this has to be done. But Lord knows I've been wrong before.

If my explanation in post #111 is flawed please explain. If that's correct then thank you for your patience.

 

[K22]

OK, you have said the exact same thing several times but I still don't understand specifically how the die is set in relation to the shell holder, when you tighten down the lock ring and when the shims are installed.

I *think* I know how this has to be done. But Lord knows I've been wrong before.

If my explanation in post #111 is flawed please explain. If that's correct then thank you for your patience.

Ok, let me try again -

1. Loosen the lock ring.

2. Place the shim you desire to be your baseline under the lock ring. I like the .010 shim because it provides me a greater range of bump.**

3. Screw the die down until it makes full contact with the shell holder. Remove all flex from the press by manipulating the die and ram until a solid contact is achieve.

4. Screw the lock ring down and lock into place with the baseline shim underneath. Use a sharpie to add a memory mark on the die body and lock ring just in case the lock ring loosens when you remove the die so you can realign.

5. The lock ring is now set and should never have to be changed. You are now set at your baseline. To increasing the amount of sizing, simply replace the .010 shim with a thinner shim. Record the shim number on the cartridge box that gives you the optimum sizing for that rifle and batch of cases for future use.

PS: Some like to choose another baseline, such as the .006 shim in which case they can increase or decrease the amount of sizing simply by replacing the .006 shim with a thicker or thinner shim.

 

[DShortt]

Ok, let me try again -

1. Loosen the lock ring.

2. Place the shim you desire to be your baseline under the lock ring. I like the .010 shim because it provides me a greater range of bump.**

3. Screw the die down until it makes full contact with the shell holder. Remove all flex from the press by manipulating the die and ram until a solid contact is achieve.

4. Screw the lock ring down and lock into place with the baseline shim underneath. Use a sharpie to add a memory mark on the die body and lock ring just in case the lock ring loosens when you remove the die so you can realign.

5. The lock ring is now set and should never have to be changed. You are now set at your baseline. To increasing the amount of sizing, simply replace the .010 shim with a thinner shim. Record the shim number on the cartridge box that gives you the optimum sizing for that rifle and batch of cases for future use.

PS: Some like to choose another baseline, such as the .006 shim in which case they can increase or decrease the amount of sizing simply by replacing the .006 shim with a thicker or thinner shim.

Someone help me out here.

If your die is tight against the shell holder you can't size the case any further. All you are doing by removing the .010" shim and replacing it with an .008" shim is changing the point at which the press arm moves by .002".

If you've done that before and sized the case again and it's now shorter than it was when checked with a comparator it's simply because you sized it a second time.

 

[K22]

Someone help me out here.

If your die is tight against the shell holder you can't size the case any further. All you are doing by removing the .010" shim and replacing it with an .008" shim is changing the point at which the press arm moves by .002".

If you've done that before and sized the case again and it's now shorter than it was when checked with a comparator it's simply because you sized it a second time.

No, I don't size it a second time once the appropriate shim for that rifle and batch of cases has been determine.

Last night I sized 20 cases for my Tikka 223 using shim .006 to push the shoulder back .001" The case were sized once, only once during this operation.

 

[DShortt]

No, I don't size it a second time once the appropriate shim for that rifle and batch of cases has been determine.

Last night I sized 20 cases for my Tikka 223 using shim .006 to push the shoulder back .001" The case were sized once, only once during this operation.

I think it's mostly a definition difference and that our methods of die setup aren't conducive.
I appreciate your patience and I'm glad your process works well for you. At the end of the day that's all that matters.

 

[BoydAllen]

If a fully formed & fired case will easily rechamber; why is it customary to bump the shoulder back at all?

The reason that we bump shoulders is to create clearance if cases are tight. If they chamber freely, there is no need....BUT cases may vary in how many firings it takes to become tight, so when you are making this determination it is a good idea to measure a good sampling of cases, after you have tried one, that is not tight. You can simply measure it and look for those that might be longer from datum to head, and then try it in your rifle. When I have time, I fire a single case until it becomes solidly tight (taking care that my rifle's lugs are properly greased) and then use that measurement as a reference for setting my die. If I have to work with once fired cases I set the die to exactly reproduce the same datum to head dimension as a once fired case, and then try it in the rifle. Most of the time it will chamber freely.

 

[DShortt]

I read that as the chamber being .005 longer than the die shell holder combination.

I read that as in his set up it takes .006" in shims to achieve. 001" of shoulder set back.

Given the conversations the last 2 days on this subject that's really all that can be said about it.

 

[marine52]

I read that as in his set up it takes .006" in shims to achieve. 001" of shoulder set back.

Given the conversations the last 2 days on this subject that's really all that can be said about it.

The shims do one thing. They allow you to change the shoulder bump w/o moving the lock ring on the die. YOU STILL HAVE TO SCREW THE DIE DOWN TO THE EXACT SAME POSITION TO ACHIEVE THE SAME BUMP AS IF YOU DID NOT HAVE THE SHIMS. Their use does not guarantee a hard solid contact between shellholder and die.

The Comp Shellholders sold by Redding and the modular Shellholders sold by Area 419 are totally different. The standard shellholder has a .125” distance between the surface that the case base sits on and the top of the shellholder ledge. Comp shellholders allow this distance to vary in order to maintain a solid die-to-shellholder contact. For example, the +10 shellholder has this distance at .135” , allowing a solid die-to-shellholder contact but providing 0.010” less bump.

 

[Benchrest Braxton]

I like nice toys too. I can hold about the same level of accuracy with my Lee press and custom dies. I can also induce .001 variance with lube or not pulling the ram consistently. (Something sounds wrong about that-pulling the ram???)

The op is complaining about .001 variance in shoulder length, and he is annealing with a torch?

My suggestion is to bump all shoulders to give a minimum .002 clearance. If you have a stubborn piece, adjust the die or spin the case in the holder a half turn and size it again. No big deal. I can give several other things that I have found can cause variations on sizing but will not.

Be more concerned with whether that stubborn piece hits where it should on the target. If it does not, chunk it and move on.

the way the zero is setup makes it extremely easy to be consistent with sizing and the amount of force applied, much more than anything else out there.

unlike most other presses, it does not camover, but instead utilizes positive stops on the linkage bars to prevent any additional movement from occurring with increased force.

might be excessive for most people, but when its nice to be able to eliminate yourself as a variable when dealing issues.

 

[Turpentine]

I hand anneal just as you do but I watch for the color change and ring to pass the shoulder about 1/4" then I'll drop The case in a water bowl. Then oven dry. The annealing seems to help with spring back which can be really bad which military cases.
The number one reason that I have found that I get a case that the head space is off is not having enough lube inside the neck. When the expander ball pulls back through a neck that doesn't have enough lube it will stretch the case. It can be severe enough that it will cause a case head separation. This plagued me somewhat when I started with military brass. Try to make sure the inside of the necks are lubed as consistently as possible. I use One Shot, Lee case lube or imperial die wax. In my case it helped but I generally use either an RCBS X die or a collet in conjunction with a Redding body die as needed these days which has also cut way down on my trimming.