Bullet Setback for 9mm...

[tightgroup tiger]

That depends on whether you are using a progressive press or a single stage.
A single stage press, you want to just touch the shell holder with it under load, with a progressive you need to make sure it touches the shell plate because of deflection of the the plate or ithe case won't be fully sized.
You and the last poster never said what press you were using.
I did.
I'm glad you got your problem worked.

 

[gcleff11]

Single stage right now for learning purposes. It's really all we need for our current shooting habits. Wish we could target shoot more, but life is busy. Progressive presses--at this point--are way above my pay grade, haha. I'm guessing I'll be posting a lot more questions if I graduate to one of those. Thanks for bearing with me in the learning curve...

 

[ballman6711]

Apologies for not being more clear, I load on a single stage. And use the paper method I mentioned above "under load". I've never loaded on a progressive or turret, so can't comment on setting those up.

I suppose I could use a feeler gauge when setting up a sizing die, but a piece of paper seems to work just as well for me. Lots of different ways to make lasagna.

chris

 

[joneb]

This might be the aha moment

It happens, we are glad you came aboard.

 

[mmb617]

I spent a good 10 mins searching for a large pistol primer that bounced off the bench (found it!). And that was not just because primers are getting scarce. I'm just wired that way. I grew up rather poor...

Good to know I'm not the only one who does that. While I'm down there on my hands and knees looking for the 3 cent primer I dropped I know it makes no sense but I can't help myself.

 

[Suedenflames68]

The paper spacer is a neat idea to make certain your not crashing into the sizing die. I think I'll borrow that

I once tried not sizing new starline 380 brass. Measured the same as some factory hornady ammo. Was using xtp 90 gr bullets. Made one up and it had what I felt was unacceptable set back after multiple chamberings. Tested the factory ammo and it was about the same. After 12 chamberings they were set back about .013"

Resized cases only moved .002" after 12 chamberings, even with those tiny little 90 bullets.

Definitely good to always resize even new or if buying processed brass.

James

 

[JimKirk]

The paper spacer is a neat idea to make certain your not crashing into the sizing die. I think I'll borrow that

I once tried not sizing new starline 380 brass. Measured the same as some factory hornady ammo. Was using xtp 90 gr bullets. Made one up and it had what I felt was unacceptable set back after multiple chamberings. Tested the factory ammo and it was about the same. After 12 chamberings they were set back about .013"

Resized cases only moved .002" after 12 chamberings, even with those tiny little 90 bullets.

Definitely good to always resize even new or if buying processed brass.

James

Folks need to take into count the "springing" of the press....when you size a brass some presses spring way more than you think ....you may start out with a paper thin gap and when sizing and end up with a nickel thick gap .... So a person needs to be sure to look at the gap when a sized brass is at the top of the stroke during the sizing process....

 

[ballman6711]

Yes, make sure you have a piece of brass in the holder while using the paper method to set up your die.

chris

 

[LiveLife]

Yes, make sure you have a piece of brass in the holder while using the paper method to set up your die.

And if using progressive press, recheck for "daylight" between the bottom of die and top of shell plate with all the stations full.

 

[Suedenflames68]

Wow, just set up to make some test loads for a new 9mm pistol. Held handle down solid with my knee and screwed resizing die down against ram as far as I can by hand with no paper shim or anything as I normally do. Locked it down. Insert brass and ran it up.....had probably .010-.015" daylight!
Suprising I never checked that or noticed before. Using lee single stage challenger press for this. Always thought the "springing" of a press like this was bogus. Thought maybe in a "c" style press. Looks to be just slight slop in all the linkage that doesnt show until it has decent resistance ,more than what my mind interpreted as press body flex whenever I heard people talking about the effect.

Learned something new! Even though I havent had any set back issues , It looks as though i can tighten it up some more. I'm still a bit of a novice. Only been doing it for a few years and about 10k rounds over several calibers. But I am pretty enthusiastic about reloading and read a lot and thought I was very meticulous about it. And I just got schooled on basics.

Seems the only cartridge i load that this would be potentially significant on would be the 9mm with its tapered case. Would think straight wall cases would just miss out on that last bit of sizing towards the base.

Just measured brass sized with normal die setting, then i screwed it down so that under load of brass it had virtually no gap.... tightened it up another .001" wow! .3705" to .3695"
Only did that at the case mouth though. The area of the body where the bullet will get its tension looks to be unchanged or maybe .0005" smaller. Having trouble getting consistent reading to be conclusive. Still , I will be changing the way I set up my sizing dies to ensure I get all that's available from them.

James

 

[LiveLife]

recheck for "daylight" between the bottom of die and top of shell plate with all the stations full.

Held handle down solid with my knee and screwed resizing die down against ram as far as I can by hand with no paper shim or anything as I normally do. Locked it down. Insert brass and ran it up.....had probably .010-.015" daylight!

Suprising I never checked that or noticed before. Learned something new!

We are kinda OCD regarding reloading 9mm that could be finicky at times as small changes can have significant effect on finished rounds.

 

[Walkalong]

Would think straight wall cases would just miss out on that last bit of sizing towards the base.

Nah, they don't care.

 

[Suedenflames68]

Hmm, well I thought I was being really scientific in my measurements. I've realized that resizing same piece has a cumulative effect and will be smaller after several passes through the die. Oh well. I'll be setting it up to account for the slop/flex from now on haha.
James

 

[LiveLife]

Hmm, well I thought I was being really scientific in my measurements. I've realized that resizing same piece has a cumulative effect and will be smaller after several passes through the die.

And depending on number of reloadings, powder charge/pressure history and condition of brass, I found brass spring back of resized case to be out-of-round and could produce oval shaped case mouth/neck.

So if you want to be more "scientific", measure the brass at 12/3/6/9 O'Clock for roundness.

And yes, subsequent resizing of brass could make it more "rounder".

 

[ballman6711]

Wow, just set up to make some test loads for a new 9mm pistol. Held handle down solid with my knee and screwed resizing die down against ram as far as I can by hand with no paper shim or anything as I normally do. Locked it down. Insert brass and ran it up.....had probably .010-.015" daylight!
Suprising I never checked that or noticed before. Using lee single stage challenger press for this. Always thought the "springing" of a press like this was bogus. Thought maybe in a "c" style press. Looks to be just slight slop in all the linkage that doesnt show until it has decent resistance ,more than what my mind interpreted as press body flex whenever I heard people talking about the effect.

James

I load on a Hornady LnL single stage press, and it will "cam over", meaning as you pull the handle down the ram will top out and then drop slightly at the end of the stroke. If I set my dies up with the lever all the way down, my ram will crash into the dies and stop the press, so I have to be pretty careful to have the ram all the way up and not cammed over. And I also have slop in my linkage, but my finished rounds are very consistent so I haven't bothered to shim the linkages.

And depending on number of reloadings, powder charge/pressure history and condition of brass, I found brass spring back of resized case to be out-of-round and could produce oval shaped case mouth/neck.

So if you want to be more "scientific", measure the brass at 12/3/6/9 O'Clock for roundness.

And yes, subsequent resizing of brass could make it more "rounder".

I have also found this to be true.

chris

 

[tightgroup tiger]

I have also.

 

[FROGO207]

A couple additional things to watch out for are getting 380 brass mixed in and looking for the internal step in 9MM brass. That brass loads differently and uses only shorter bullets so I just scrap those for now.

 

[murf]

and thought I was very meticulous about it.

most of us here go way beyond meticulous and are well into the ocd realm. welcome to our nightmare!

a dial caliper is indispensable for figuring out what is "wrong" with your reloads.

luck,

murf

 

[eyeshot]

Yes, make sure you have a piece of brass in the holder while using the paper method to set up your die.

chris

So . . being new how do you use the paper method with brass in the holder? Is this a seasoned reloader joke?

My Lyman instructions say to use a matchbook cover between the holder and the die. Which I've done. But only with T/C dies. I am assuming their fear is that reloaders will trash the carbide even though, on mine, the carbide ring is recessed. Seems like outdated instructions to me.

Not sure why you set up the die differently between carbide and non-carbide if the carbide ring is recessed. Enlighten me.

 

[ballman6711]

So . . being new how do you use the paper method with brass in the holder? Is this a seasoned reloader joke?

My Lyman instructions say to use a matchbook cover between the holder and the die. Which I've done. But only with T/C dies. I am assuming their fear is that reloaders will trash the carbide even though, on mine, the carbide ring is recessed. Seems like outdated instructions to me.

Not sure why you set up the die differently between carbide and non-carbide if the carbide ring is recessed. Enlighten me.

Lol, I'm hardly seasoned, I just started loading two years ago this month. And no, it's not a joke.

Here is a picture for an example. This is my RCBS carbide size die, shellholder, and a piece of new Starline 480 Ruger brass on my Hornady LnL single stage press. I have inserted a small piece of paper between the shellholder and the die on the left side to show the placement. On the right side you can see a bit of light between the shellholder and die.



The gap between the die and shellholder in this picture is acceptable to me for a straight walled case, and gives plenty of neck tension. BUT, with a tapered case such as the 9mm, this is too much space and may not give sufficient neck tension to prevent setback. If this were a tapered case the die would need to be screwed down a bit more.

About the press "springing" or "flexing", I'll try to explain. The die in the above pic was setup without a piece of brass in the holder using the paper method. The paper would not pull out. Inserting a piece of brass into the holder and raising the ram to the top of the stroke the same piece of paper will freely slide between the holder and the die. This is due to the resistance of the brass moving into the die, which removes any slop in your linkage, ram, etc..., hence the "springing" effect.

Setting your sizing die on a single stage this way will prevent the ram from crashing into the die, which in my opinion only accelerates wear on your press and die.

Again, this setting gives me plenty of neck tension on straight wall cases, but would not be sizing down far enough for tapered cases.

Hope this helps!

chris

 

[Toprudder]

Thinking out loud here.

There are tapered cases - which 9mm is - and then there are tapered sizing dies. A typical carbide sizing die is not truly tapered, the carbide ring that does the sizing is just a ring at the bottom of the die. It does not put a true tapered profile on the cases, the O.D. will be constant for some distance from the case mouth. I don't see where a few thousandths difference in the sizing die adjustment is going to cause a difference in neck tension. A typical steel sizing die is tapered, and I can see where a few thousandths difference in die adjustment can cause a difference in neck tension.

Some time ago, I took a look at all the different headstamps of 9mm that I could find (somewhere over 20 total) and I found that there were significant differences between the different headstamps. Most had a constant wall thickness for about 0.2" from the case mouth, and then the wall thickness tapered. For some headstamps, the taper began at the case mouth. Of course, there were differences in the thickness of the walls between them. All of these can and will affect neck tension. If only a handful of cases have setback, and then the sizing die is "set waaaay lower" and the problem goes away, then I think the problem was a combination of improper adjustment AND a particular headstamp. The question of which headstamp was asked but I don't think was ever answered.

 

[eyeshot]

I woke up this morning, thinking . . . which I wasn't last night and realized what you were referring to in your post.

There are situations where sleep and comprehension are required. Sorry about that but I thought you were doing the "board stretcher thing" with the new guy.

Lol, I'm hardly seasoned, I just started loading two years ago this month. And no, it's not a joke.

Here is a picture for an example. This is my RCBS carbide size die, shellholder, and a piece of new Starline 480 Ruger brass on my Hornady LnL single stage press. I have inserted a small piece of paper between the shellholder and the die on the left side to show the placement. On the right side you can see a bit of light between the shellholder and die.

View attachment 925180

The gap between the die and shellholder in this picture is acceptable to me for a straight walled case, and gives plenty of neck tension. BUT, with a tapered case such as the 9mm, this is too much space and may not give sufficient neck tension to prevent setback. If this were a tapered case the die would need to be screwed down a bit more.

About the press "springing" or "flexing", I'll try to explain. The die in the above pic was setup without a piece of brass in the holder using the paper method. The paper would not pull out. Inserting a piece of brass into the holder and raising the ram to the top of the stroke the same piece of paper will freely slide between the holder and the die. This is due to the resistance of the brass moving into the die, which removes any slop in your linkage, ram, etc..., hence the "springing" effect.

Setting your sizing die on a single stage this way will prevent the ram from crashing into the die, which in my opinion only accelerates wear on your press and die.

Again, this setting gives me plenty of neck tension on straight wall cases, but would not be sizing down far enough for tapered cases.

Hope this helps!

chris

 

[gcleff11]

@Toprudder... All the cases I was having difficulty with were not the same headstamp. 4 or 5 different ones, actually. And please forgive the colloquial way I have for describing things. Or....don't.

 

[Toprudder]

@Toprudder... All the cases I was having difficulty with were not the same headstamp. 4 or 5 different ones, actually. And please forgive the colloquial way I have for describing things. Or....don't.

No problem! Its all good.