Need Help: How to stop shoulder rebounding

[cobus13]

So I have a question. I am new to reloading and been having issues with bumping my shoulders back. So I will bump the shoulders (then measure) and they will be where they need to be, then when I load my bullet and measure the shoulder again some will be fine and others would have changed to the point of they wont fir in my gun. I am sure I am just doing something stupid but I am stuck and need help.

Thank you

 

[straightshooter1]

Are you full length sizing?

How many firings do you have on those cases?

Are you annealing?

When you're not getting enough headspace (that's what bumping the shoulder's back effects) after springback, two things can help: 1. adjust your sizing die to where you get an increase the amount of shoulder bump to mitigate that springback. 2. Anneal your brass (like after every firing) and that will mitigate springback and make your headspace measurement much more consistent.

 

[TheOfficeT-Rex]

How much are you bumping the shoulder back and how are you measuring?

 

[cobus13]

I have a RCBS Digital Caliper, I'm bumping the shoulders back about 3k. I also have the SAC 30degree comparator to measure my shoulders.

 

[cobus13]

Are you full length sizing?

How many firings do you have on those cases?

Are you annealing?

When you're not getting enough headspace (that's what bumping the shoulder's back effects) after springback, two things can help: 1. adjust your sizing die to where you get an increase the amount of shoulder bump to mitigate that springback. 2. Anneal your brass (like after every firing) and that will mitigate springback and make your headspace measurement much more consistent.

I have 3 fires on my brass, and yes I am using a full length sizing dye. have not annealed it.

 

[straightshooter1]

I have 3 fires on my brass, and yes I am using a full length sizing dye. have not annealed it.

The more firings you do on them the more spring back you're going to see, as each firing work hardens the brass a little more each time and eventually cracks will appear. This is why many reloaders will anneal their brass in order to significantly lessen the work hardening.

So, if you're not going to anneal, you're going to have to adjust your die to give you more set back allow for the springback. One other thing you can do to help is to have plenty of dwell time when you push the case into the die. That is, push the case into the sizing die and let it sit there for 5-10 seconds before pulling it out to give the brass time to form and you'll get a little less springback and more consistency.

 

[TheOfficeT-Rex]

Something is not right with your measurements or process. Because the issue is intermittent, there must be some difference. Same lot of brass? Can you elaborate on process and components?
I don't think you'd get 3k of springback if they're all coming out of the die at the proper setback.

 

[cobus13]

The more firings you do on them the more spring back you're going to see, as each firing work hardens the brass a little more each time and eventually cracks will appear. This is why many reloaders will anneal their brass in order to significantly lessen the work hardening.

So, if you're not going to anneal, you're going to have to adjust your die to give you more set back allow for the springback. One other thing you can do to help is to have plenty of dwell time when you push the case into the die. That is, push the case into the sizing die and let it sit there for 5-10 seconds before pulling it out to give the brass time to form and you'll get a little less springback and more consistency.

thank you for the advice, I will make the adjustments as well as get an annealer. really appreciate it.

 

[cobus13]

Something is not right with your measurements or process. Because the issue is intermittent, there must be some difference. Same lot of brass? Can you elaborate on process and components?
I don't think you'd get 3k of springback if they're all coming out of the die at the proper setback.

talking to straightshooter1, it sounds like since i have fired it 3 times i should look at annealing. but i will absalutly tell you my process incase i failed to mention something important.
1: so i know post fire my shoulders are 1.440
2: using a full length sizing dye i bump the shoulders to 1.437 (measure it to make sure)
3: then i deburr/camphor
4: then i measure my shoulder one more time before staring the final loading process. (this is where i find that some of my shoulders have "bounced back"

 

[2aBaC̶a̶]

Do cases ever feel like the get stuck in the die? Ive found different lubes can give inconsistent bumps.

 

[straightshooter1]

Do cases ever feel like the get stuck in the die? Ive found different lubes can give inconsistent bumps.

Yup, I tend to agree. If the sizing doesn't feel relatively easy and smooth, it tends to lead to inconsistent bumps. And lubes can be a key factor for that. I switched to Imperial Sizing Die Wax a few years ago and haven't looked back.

 

[cobus13]

Do cases ever feel like the get stuck in the die? Ive found different lubes can give inconsistent bumps.

yes, i have actually got a few stuck, I use Frankford Arsenal case lube.

 

[supercorndogs]

You would have to be running real low clearance on your bump for annealing to be making the difference here. Not just that, but if they are all coming out of the FL die the same like the OP seems to state. Then I would be looking at the seating die being screwed down too far.

 

[cobus13]

Okay, so if I under you correct take a look at the seating dye and having to much cam over ?

 

[Dthomas3523]

I have trouble believing you’re getting .003 spring back in the shoulder.

Have you verified this by measuring a piece of brass and then seeing the spring back in that *exact* same piece of brass? As in, you sized a piece of brass, it measured fine and it chambered in your rifle......then that exact same piece of brass wouldn’t chamber after seating?

 

[cobus13]

I have trouble believing you’re getting .003 spring back in the shoulder.

Have you verified this by measuring a piece of brass and then seeing the spring back in that *exact* same piece of brass? As in, you sized a piece of brass, it measured fine and it chambered in your rifle......then that exact same piece of brass wouldn’t chamber after seating?

Yes sir, I even measured every piece of brass after bumping the shoulders. Out of 50 pieces of brass I do I would get 5 pieces that would spring back after I seat the bullet . I’m sure I am doing something wrong and need to re evaluate what I’m doing. But from the advice I got here I’m hoping it fixes my problem I’m having.

 

[2aBaC̶a̶]

talking to straightshooter1, it sounds like since i have fired it 3 times i should look at annealing. but i will absalutly tell you my process incase i failed to mention something important.
1: so i know post fire my shoulders are 1.440
2: using a full length sizing dye i bump the shoulders to 1.437 (measure it to make sure)
3: then i deburr/camphor
4: then i measure my shoulder one more time before staring the final loading process. (this is where i find that some of my shoulders have "bounced back"

What steps are adding powder and seating the bullet? You have noted the difference after debur and chamfer and also after seating the bullet and.

also, what kind of press and how do you drop powder?

 

[cobus13]

What steps are adding powder and seating the bullet?

What kind of press and how do you drop powder?

After step 4 I add the primer then powder then bullet.

 

[Dthomas3523]

Did you size them down so that your bolt free falls without ejector and cocking piece? Or is there a little resistance in your initial shoulder bump?

 

[cobus13]

Did you size them down so that your bolt free falls without ejector and cocking piece? Or is there a little resistance in your initial shoulder bump?

There is resistance in my initial shoulder bump.

 

[Dthomas3523]

There is resistance in my initial shoulder bump.

Sizing them down to where the bolt falls free with gravity will likely alleviate the issue. Since there is resistance already, any amount of spring back or sizing differences due to lube is going to take small resistance and make it not so small.

 

[cobus13]

Sizing them down to where the bolt falls free with gravity will likely alleviate the issue. Since there is resistance already, any amount of spring back or sizing differences due to lube is going to take small resistance and make it not so small.

Thank you for the advice.

 

[Dthomas3523]

What seatingg die are you using? And is it for some reason tight fitting on the cases that are growing after seating?

 

[cobus13]

So I use a full length body die. I have a .291 bussing in there.

 

[Dthomas3523]

Meant seating. What seating die? And is there plenty of clearance on the body?

 

[cobus13]

Meant seating. What seating die? And is there plenty of clearance on the body?

MatchMaster seating die. As far as clearance goes I screwed it in till it was touching the shell holdEr in the up position. (There is no cam over )

 

[cobus13]

Just wanted to say thank you to every one that gave me advice, got some of my brass annealed yesterday and paid a little closer attention and looks like I'm doing good and back in business.

Really appreciate it.

 

[Milo 2.5]

Glad you got up and running, but do pay attn to consistent lube. Most of the time you will never feel it when the case enters the die, it is on the upstroke pulling the case back out from the die, you will feel a hangup, that is your key point indicator of inconsistent lube.

 

[chadrp]

A question i would have is if you are measuring the shoulders on finished rounds or primed brass prior to charging and seating, are you getting the primers seated below flush? A slightly protruding primer is going to skew that measurement. If i have a round that has a slight resistance closing the bolt it is usually a protruding primer. I used to seat .002 below flush on my cps but now I seat deeper due to inconsistencies in the once fired factory brass im using.