Sizing Mandrels vs FL sizing die with expander ball??

[BFD]

Checked my gear again after all this rumination on precision neck work:
.306 with .307 mandrel:

Bullet dia calipers:

Now it’s been stated a couple times now that .0005 is beyond worrying about. Calipers are accurate to .001. But for fun I calibrated with micrometer:


Above is neck pre bullet seat. Below is after:

So, I nailed my .002 NT measuring both ID and OD. If you know your calipers are good and calibrated you can rely on the opposing blades to measure NT. This is the second confirmation test I’ve done. Only this one documented & shared.

 

[aratliff]

Thank you, @BFD for edifying us all here. And I am not blowing sunshine up your skirt. I’ll only speak for myself, but I appreciate you treating me like I am from Missouri and showing me that what I have been doing all along is, in fact, perfectly permissible. (Like the alliteration?)
xoxo

 

[BFD]

Thank you, @BFD for edifying us all here. And I am not blowing sunshine up your skirt. I’ll only speak for myself, but I appreciate you treating me like I am from Missouri and showing me that what I have been doing all along is, in fact, perfectly permissible. (Like the alliteration?)
xoxo

Well, I do try my best to match my delivery to my audience, so I chose to “break things down shotgun style” for you specifically.

I’ve found there’s couple kinds of information presented on forums: Regurgitation of things that sound plausible, but never tested personally, and what’s presented by personal experience & testing. I love to fall for the former, but try to live by the latter.

 

[aratliff]

You, Sir, should be awarded an honorary doctorate in education.
I’m sure there is a fancy abbreviation for that degree, but it is escaping my recollection at the moment. Whatever they are, you should list the letters behind your forum handle.

 

[Berrnard]

Checked my gear again after all this rumination on precision neck work:
.306 with .307 mandrel:
View attachment 6812
Bullet dia calipers:
View attachment 6813
Now it’s been stated a couple times now that .0005 is beyond worrying about. Calipers are accurate to .001. But for fun I calibrated with micrometer:
View attachment 6814
View attachment 6815
Above is neck pre bullet seat. Below is after:
View attachment 6816
So, I nailed my .002 NT measuring both ID and OD. If you know your calipers are good and calibrated you can rely on the opposing blades to measure NT. This is the second confirmation test I’ve done. Only this one documented & shared.

ya we cant trust that micrometer, the batteries are almost dead!

 

[gltaylor]

You, Sir, should be awarded an honorary doctorate in education.
I’m sure there is a fancy abbreviation for that degree, but it is escaping my recollection at the moment. Whatever they are, you should list the letters behind your forum handle.

Best I ever heard was PDH as a subscript.
Stands for "pretty damn handy" !!!!!

 

[BFD]

ya we cant trust that micrometer, the batteries are almost dead!

Hilarious! I saw that and thought “Some Smartass gonna say something about that battery indicator!”

 

[HARPERC]

Hilarious! I saw that and thought “Some Smartass gonna say something about that battery indicator!”

Batteries? I wonder if that's why mine stopped working?

 

[jrebel]

Well.....got the mandrels today and started messing with them. I think I need to order a couple more sizes....?? I used the .2630 for the creedmoor and noticed the brass springs back, just increasing the size by 1.5 thousandths.....for 2.5 thousandths neck tension. Knowing this, I think a .2635 or .2640 would give me closer to a 2 thousandths neck tension with this brass.

All the above being said.....I shrunk my ES and SD substantially. I went from an ES in the 20 to 30 (depending on the group I was chronoing) to and ES of 8.5.

I didn't notice an appreciable difference in group size, but I am still working with this tuner brake so we will see what happens. It is currently shooting 3/4" groups consistently.

 

[BFD]

I think a .2635 or .2640 would give me closer to a 2 thousandths neck tension with this brass.

.264

 

[BFD]

.All the above being said.....I shrunk my ES and SD substantially. I went from an ES in the 20 to 30 (depending on the group I was chronoing) to and ES of 8.5.

I didn't notice an appreciable difference in group size, but I am still working with this tuner brake so we will see what happens. It is currently shooting 3/4" groups consistently.

This says you’re getting your combustion in check. Nice!

 

[JakeC]

If you measure inside diameter with calipers before and after using the expander mandrels, you should see the difference which will give you starting point. May not be exact...but for for the purposes of neck tension, it should be really close.

That's what I figure. You can easily get it as or more precise than the mandrel increments. If i can read dozens of fired cases to the same .0005 increment with the ID prongs then it's accurate enough for this operation.