Fired brass headspace grows after FL resizing

[dnellans]

Y’all didn’t actually read his post before deciding to reply did you?

If the base to shoulder junction distance is off by .025-.030 as measured with a caliper, no amount fucking around with a shell holder is going to fix the problem. That die is mis-manufactured or they call their “dasher” spec something non-standard. Call the die maker and tell them your measurement, they should be able to confirm the intended spec. .025 is too much to try and “fix” for anyone who doesn’t do their own machine work

 

[6BRA]

Not really. Alpha brass was available a long time before they had reamers. The marketing says they're made for each other... in other words... they're made for saami specs

There is a long discussion from Alex Wheeler on Alpha OCD being specced differently than original Alpha brass. His info came straight from the horse! Titled Alpha 6BRA BRASS.

 

[marine52]

Wrong. The the Redding shell holder set starts with a standard shell holder and the others are taller, in .002 increments. To get a shorter shell holder you will have to make it, but shell holders are inexpensive and the process is not difficult.

There is so much confusion on the use of Redding comp shellholders. Primarily because of Redding’s worthless description/instructions on their use

From Redding: “ Each shellholder has a distinct black oxide finish and is clearly marked to indicate the amount it will decrease case-to-chamber headspace”. What? totally incomprehensible.

The Comp Shellholders sold by Redding and the modular Shellholders from Area 419 work the same way. They lower the floor of the shellholder that the case base sits on. So for one marked +4, the floor is dropped 0.004” and generates a sized case with 0.004” less bump (longer base-to-datum length) relative to a standard .125” shellholder. This difference is important because you don’t have to touch the die to see the change and you can adjust bump w/o having the die in firm solid contact with the shellholder. However, many of us like that solid contact and these comp shellholders can be interchanged w/o adjusting the die because the shellholder shelf that contacts the die is not shifted.

if you grind say 0.004” off the top of the shelf of your standard shellholder you have to have that firm solid contact with the shellholder in order to realize the added .004 bump. You do this by screwing the die down to obtain the same contact with the shellholder.

The diagram and the numbers below were produced by a New Zealand shooter using his Mitutoyo micrometer. The column “headspace effect” really should read “shoulder setback effect.”

 

[Turpentine]

I saw this a lot years ago. Today things are some what better.
I refuse to put a dirty case in any of my dies, so they get cleaned before I size. I the rattle the cases around in a box until majority is mouth up, then apply my spray lube. Then I let them set till the alcohol has flashed off. I then clean them again. The lube in the case and on the mouth cause powder to stick and I get wonky results with lube residue in the mouth. This is with an expander ball on some ammo I load. Works for me.
Bushing dies are whole different thing in my shop.

Today I generally use One Shot and let it dry If I'm full length sizing. Some calibers I use a collet and a body die. In 308 I use an X die which keeps my brass from needing to be trimmed And my accuracy with it has been very good. I'll often tumble to begin with as well If my cases are dirty. I anneal often, then size and generally tumble before I load again. That way I don't have to deal with powder sticking in the neck. I don't mess with as much Mil brass as I used to but I'll generally tumble the heck out of it before I do anything else nowadays. I have some LC 66-67 match and LC 85 match I've hung on to because I have some really good loads with it for my gas guns and it's tough stuff.

 

[JSH]

Y’all didn’t actually read his post before deciding to reply did you?

If the base to shoulder junction distance is off by .025-.030 as measured with a caliper, no amount fucking around with a shell holder is going to fix the problem. That die is mis-manufactured or they call their “dasher” spec something non-standard. Call the die maker and tell them your measurement, they should be able to confirm the intended spec. .025 is too much to try and “fix” for anyone who doesn’t do their own machine work

Wow, and when you mess with a wildcat no matter how popular, specs on dies, reamers and even FACTORY brass can be all over the place, so I do t know where you just decided it was a die issue.

And NO I did not do the math before I responded. Oddly enough, I have a current 6BR that I had to fix a shell holder.

 

[JFrank]

Y’all didn’t actually read his post before deciding to reply did you?

If the base to shoulder junction distance is off by .025-.030 as measured with a caliper, no amount fucking around with a shell holder is going to fix the problem. That die is mis-manufactured or they call their “dasher” spec something non-standard. Call the die maker and tell them your measurement, they should be able to confirm the intended spec. .025 is too much to try and “fix” for anyone who doesn’t do their own machine work

Where do you get .020 ?

 

[LVLAaron]

There is a long discussion from Alex Wheeler on Alpha OCD being specced differently than original Alpha brass. His info came straight from the horse! Titled Alpha 6BRA BRASS.

I don't know anything about the BRA. I did see the thread. Unfortunately, there's a mismatch on ONE case that Alpha makes. Lots of people using Alpha brass and winning trophies that don't use alpha reamers.

 

[dnellans]

I was re-sizing some 4-5times fired 6 Dasher Alpha OCD brasses using a newly received FL sizing die, found the headspace grows about 0.0015-0.0020" after resize.
Fired brass headspace: 1.1935-1.1940"
After resizing headspace: 1.1950-1.1955"

1.My initial setup was, push the press handle all the way down(rise the ram all the way up) and screw the FL sizing die all the way down to touch the shell holder firmly. The decapping pin, expander and rod assembly is uninstalled.

2.Then I made some changes based on my initial setup, after lower the press ram down, I give the FL sizing die additional 1/4 turn towards the shell holder, in case there were some gap, now the shell holder and the bottom of the die are contacting tightly.
But, same result.

I repeated the above 2 methods using Redding competition shell holders, tried 0.002, 0.004 and 0.010 ones, all give the same result.

3. Based on my initial setup, I give the FL sizing die more adjustment going down, add from 1 full turn to 3 full turn step by step. At some point I wasn't sure exactly how much adjustment I made, probably around 2 full turns, it actually resized the brass with increased headspace from 1.1955" down to 1.1910". Unfortunately, I lost that point when I tried to back the FL sizing die up a
4. Tried with a Redding Type S FL sizing die using my initial setup, it works as expected, sized brass to 1.192+/-0.0005" including those brasses I tried above with increased headspace.

As I suspect the new sizing die might have a longer body, I used depth rod on my caliper measured the depth from the bottom of the die to the brass body and shoulder joint point inside the sizing die, I got approximately:
1.100+/-0.005" for the new FL sizing die
1.070+/-0.002" for the Redding Type S FL sizing die
Seems there is 0.025-0.030" difference.

Does this sounds like a manufacturing issue with the sizing die? or something I did wrong. Thank you.

Where do you get .020 ?

Read all the way to the bottom of his original post.

He has measured the base to shoulder junction of his sizing dies with a caliper and they are off by .025-.030 between the two…

————-
4. Tried with a Redding Type S FL sizing die using my initial setup, it works as expected, sized brass to 1.192+/-0.0005" including those brasses I tried above with increased headspace.

As I suspect the new sizing die might have a longer body, I used depth rod on my caliper measured the depth from the bottom of the die to the brass body and shoulder joint point inside the sizing die, I got approximately:
1.100+/-0.005" for the new FL sizing die
1.070+/-0.002" for the Redding Type S FL sizing die
Seems there is 0.025-0.030" difference.

Does this sounds like a manufacturing issue with the sizing die?

 

[JFrank]

Read all the way to the bottom of his original post.

He has measured the base to shoulder junction of his sizing dies with a caliper and they are off by .025-.030 between the two…

————-
4. Tried with a Redding Type S FL sizing die using my initial setup, it works as expected, sized brass to 1.192+/-0.0005" including those brasses I tried above with increased headspace.

As I suspect the new sizing die might have a longer body, I used depth rod on my caliper measured the depth from the bottom of the die to the brass body and shoulder joint point inside the sizing die, I got approximately:
1.100+/-0.005" for the new FL sizing die
1.070+/-0.002" for the Redding Type S FL sizing die
Seems there is 0.025-0.030" difference.

Does this sounds like a manufacturing issue with the sizing die?

No it sounds like a measuring issue to me. To be quite honest I didn’t get into the comparing of dies , I just concentrated on the sizing question at the beginning of the post.

 

[K22]

TL/DR

If base to shoulder is growing during sizing, the die isn't touching the shoulder. Its squeezing the brass and pushing it up.

This the correct answer in my experience.

The OP is extruding the case - very common when the die does not at least touch the shoulder to prevent forward movement of the case while the FL die is compressing the case.

 

[longrangeprecisionshooter]

This may be an absolutely stupid comment but I figure I'll make it anyway. I have had the headspace actually increase, particularly using tough military brass, due to not sufficiently lubricating the inside of the necks. When the expander ball pulls back through the neck the lack of lube would cause it to pull and lengthen the case and give inconsistent results. Enough of this pulling, stretching will actually weaken the case walls. Like I said I may be totally off base but figured I would throw it out there. It definitely wouldn't be the first time Ive been wrong.

I am not using military brass, but I did feel the same stretching/resistance when lower the press ram to pull the brass out from the die. Give more case lube helps making it more smooth, but the headspace still grows in my case.
Thanks anyway.

 

[longrangeprecisionshooter]

Y’all didn’t actually read his post before deciding to reply did you?

If the base to shoulder junction distance is off by .025-.030 as measured with a caliper, no amount fucking around with a shell holder is going to fix the problem. That die is mis-manufactured or they call their “dasher” spec something non-standard. Call the die maker and tell them your measurement, they should be able to confirm the intended spec. .025 is too much to try and “fix” for anyone who doesn’t do their own machine work

Yeah, that's what I thought when I measure the depth from the bottom of the die to the shoulder/body joint in the die, not very accurate, but should be within that +/- range.

Reaching out to the manufacturer and see what they say about it.

 

[longrangeprecisionshooter]

There is so much confusion on the use of Redding comp shellholders. Primarily because of Redding’s worthless description/instructions on their use

From Redding: “ Each shellholder has a distinct black oxide finish and is clearly marked to indicate the amount it will decrease case-to-chamber headspace”. What? totally incomprehensible.

The Comp Shellholders sold by Redding and the modular Shellholders from Area 419 work the same way. They lower the floor of the shellholder that the case base sits on. So for one marked +4, the floor is dropped 0.004” and generates a sized case with 0.004” less bump (larger base-to-datum length) relative to a standard .125” shellholder. This difference is important because you don’t have to touch the die to see the change and you can adjust bump w/o having the die in firm solid contact with the shellholder. However, many of us like that solid contact and these comp shellholders can be interchanged w/o adjusting the die because the shellholder shelf that contacts the die is not shifted.

if you grind say 0.004” off the top of the shelf of your standard shellholder you have to have that firm solid contact with the shellholder in order to realize the added .004 bump. You do this by screwing the die down to obtain the same contact with the shellholder.

The diagram and the numbers below were produced by a New Zealand shooter using his Mitutoyo micrometer. The column “headspace effect” really should read “shoulder setback effect.”

View attachment 1428528

Thanks a lot.

That's really helpful. I agree the description on Redding's website is really confusing.
I guess I am not be the only person thought it is going the other direction: Say my fired brass headspace is 1.193", if I want 0.002" bump when FL resizing, use the +0.002 shell holder from the set would by my choice and have a firm touch between shell holder and the die would get the job done with 1.191" headspace.
But it actually goes to an opposite direction, by using the +0.002 shell holder, I am kind of extending the headspace, most likely to 1.195", right?

 

[marine52]

Thanks a lot.

That's really helpful. I agree the description on Redding's website is really confusing.
I guess I am not be the only person thought it is going the other direction: Say my fired brass headspace is 1.193", if I want 0.002" bump when FL resizing, use the +0.002 shell holder from the set would by my choice and have a firm touch between shell holder and the die would get the job done with 1.191" headspace.
But it actually goes to an opposite direction, by using the +0.002 shell holder, I am kind of extending the headspace, most likely to 1.195", right?

Yes that is correct. In your case, the comp shellholders won’t help and exacerbate the problem. I would send the die back. Sounds like it is out of spec.

 

[longrangeprecisionshooter]

No it sounds like a measuring issue to me. To be quite honest I didn’t get into the comparing of dies , I just concentrated on the sizing question at the beginning of the post.

I didn't expect it could be a die manufacturing issue from the beginning, I thought I didn't set up the die properly.

As you can see, I tried all the possible approaches from what I can think of and asked around before I post here, I couldn't figure out why Redding die works as expected and the one I newly received extending the headspace.

In the end, I thought unless the die body part is too long, otherwise there is no way it is not touching the brass shoulder. Therefore, I measured the depth from bottom of the die to the shoulder body joint inside the die.
I know this is not a accurate measurement, but at least we see some double digits difference.

And a couple of the brass have longest headspace before resizing at 1.195" (while most are 1.1935"), after resize, it got stretched to 1.197", if I try to chamber the extended brass, I can't really close the bolt.

 

[Fast14riot]

Proper way to measure the die would be to use a steel ball inside that is smaller than the shoulder diameter and a depth mic. Bit of math involved if you want absolute measurement or can just be used to compare with relative measurements if the reasonable assumption is the cone angle (shoulder angle) is exactly the same between the two.

 

[Webster]

I was re-sizing some 4-5times fired 6 Dasher Alpha OCD brasses using a newly received FL sizing die, found the headspace grows about 0.0015-0.0020" after resize.
Fired brass headspace: 1.1935-1.1940"
After resizing headspace: 1.1950-1.1955"

1.My initial setup was, push the press handle all the way down(rise the ram all the way up) and screw the FL sizing die all the way down to touch the shell holder firmly. The decapping pin, expander and rod assembly is uninstalled.

2.Then I made some changes based on my initial setup, after lower the press ram down, I give the FL sizing die additional 1/4 turn towards the shell holder, in case there were some gap, now the shell holder and the bottom of the die are contacting tightly.
But, same result.

I repeated the above 2 methods using Redding competition shell holders, tried 0.002, 0.004 and 0.010 ones, all give the same result.

3. Based on my initial setup, I give the FL sizing die more adjustment going down, add from 1 full turn to 3 full turn step by step. At some point I wasn't sure exactly how much adjustment I made, probably around 2 full turns, it actually resized the brass with increased headspace from 1.1955" down to 1.1910". Unfortunately, I lost that point when I tried to back the FL sizing die up a little bit so it will size the brass to 1.192" and I can't find where that point is after.

Here is a photo of the brass after resized with black marker covers from neck/shoulder joint to the top of the body.
It seems there are contact/force applied on the body and the joint between body and shoulder, but no contact or only a minor scratch on the shoulder.
View attachment 1428268


4. Tried with a Redding Type S FL sizing die using my initial setup, it works as expected, sized brass to 1.192+/-0.0005" including those brasses I tried above with increased headspace.

As I suspect the new sizing die might have a longer body, I used depth rod on my caliper measured the depth from the bottom of the die to the brass body and shoulder joint point inside the sizing die, I got approximately:
1.100+/-0.005" for the new FL sizing die
1.070+/-0.002" for the Redding Type S FL sizing die
Seems there is 0.025-0.030" difference.

Does this sounds like a manufacturing issue with the sizing die? or something I did wrong. Thank you.

Don't see a neck I.D. chamfer? Could be why you have scratches on the case body. Tiny pieces of brass can break off and get into the die.

 

[10XSHOOTER]

Go to a machine shop and have .005 - .010 ground off the bottom of your die. I've had to do this lately with Redding Type S full length dies. the comp shell holders won't do t!

 

[Webster]

Wrong. The the Redding shell holder set starts with a standard shell holder and the others are taller, in .002 increments. To get a shorter shell holder you will have to make it, but shell holders are inexpensive and the process is not difficult.

Something I have thought about. When increasing the bump are you moving the the harder body/ shoulder junction back or just caving in the more movable flat shoulder more concave. In otherwords the corner doesn't get moved. I believe the bump gauge measures off the middle of the shoulder not the transition from body to shoulder? Are we just making the shoulder more concave? If your moving the body/shouder junction back the body must get a little bigger in diameter?

 

[longrangeprecisionshooter]

Don't see a neck I.D. chamfer? Could be why you have scratches on the case body. Tiny pieces of brass can break off and get into the die.

Do you mean I didn't chamfer/debur the brass and could cause tiny pieces of brass left inside the die so have scratches?
I don't see anything brass piece inside the die when I measured the depth from bottom of the die to shoulder/body joint.