FLS and brass flow

[Bc'z]

Since I've stopped neck sizing and committed to only full length sizing I've noticed excessive brass flow on my 30-06 brass, .008-.010.
Wilson FL bushing die.
All brass was trimmed to length then body and necks were sized with rcbs FL die.
21st century expander mandrel.
Necks turned
Loaded and fired.
After FL sizing with my Wilson .008-.010 growth in necks.
Die was set to hold shoulders in place and not bump, trying to let brass grow to fit new chamber.
Brass I fired yesterday measures .003-.0035 @ shoulder body junction and just above the web larger than sized brass.
I know Wilson will hone the die.
I'm thinking if it didn't size body as much maybe necks wouldn't grow excessively.

What is the minimum amount to size body of brass but still get smooth reliable chambering?

 

[MikeMcCasland]

When you say your necks are growing excessively, are you saying the OAL of the case is growing .008-.010" after first firing/sizing?

As far as adjusting the amount of body (not shoulder) sizing, I don't think that's possible unless you hone the die. You basically "get what you get" when the die is setup to bump shoulders.

If it were me, I'd trim them one more time. I'm betting they won't grow near as much the next time around. Edit: That is, if I understand what you're saying correctly.

 

[B23]

Until the inside of the die comes in contact with the shoulder on your brass, it's very normal for brass to come out of a FL die, longer, than when it went in.

As a piece of brass goes up inside a FL die the first thing it does is squeeze down on the body of the case and as it's sizing the body down, brass flows in the direction of least resistance, which is up. Brass generally gets a little longer until it contacts the shoulder sizing portion of the die, then it gets pushed back down. If your FL die isn't screwed down far enough for the shoulder to get pushed back, it's normal for your cases to come out longer than when they went in. This is why people who try and neck size only, with a FL die, end up with cases that won't chamber in their gun.

 

[Uncle Ed]

As stated above when you size and squeeze a fired case the brass flows upward in the die. The larger the diameter of the chamber and the smaller the diameter of the die the more the case will grow when sized.

Dies and chambers vary in size, I have a Lee full length .223 die that reduces the case diameter more than my RCBS small base die.

On a semi-auto the resized case should be .003 to .005 smaller in diameter than its fired diameter. This allows the case to spring back from the chamber walls and extract reliably.

Bottom line, with my milsurp rifles with big fat chambers the cases grow even more when full length resized. The only solution is a custom made die made to the dimensions of a fired case.

Below just shows the variations in .308 Forster dies.

Below the chamber diameter can vary .002 and be within SAAMI limits. (.4708 to .4728 at the base)

 

[Bc'z]

After firing, die was set to hold shoulders in place and not bump.
Set die up using feeler gauge started with .010, shoulders moved forward, went to .008 this held them to same measurement as fired case.
Using hornady comparitor I measured new un fired brass for datum measurement for setting up die for new chamber.
Trimmed, loaded, fired, sized, excessive growth, back to trimming.

I was having the same issue on my 6x45 brass using a rcbs small base die, switched to a Redding FL die for that cartridge and growth in necks was .0015 alleviating the need to trim every firing.

My thinking is if body isn't sized as much I wont see as much growth.
That's why I'm asking what is the minimum amount I need to size body of brass for trouble free chambering.

 

[JFrank]

Brett
I’ll check again but I don’t recall my 308 growing hardly at all after I stopped using an expander system and went to the Wilson.
My chamber is Tikka and I’m not sure if it’s CIP or SAMMI or if that even makes a difference nevertheless my brass only sizes about .002


J

 

[Bc'z]

@SPJ
I should've left the factory barrel on, sumbitch shot .25" groups religiously.
Just a bitch to get the copper out of it.
New barrel cleans in jiffy and refuses to copper foul.

I've fought over pressure with my lapua brass, as necks were to thick for new chamber.
Now I'm neck turning.

Now the difference of new chamber to the die dimensions, causing me to trim every firing.

This whole project has been a huge pain in the ass!!
And for what?
Frustration and futility?
Groups that are .25" bigger than I got with original barrel?
A freaking BOSS system that comes
unscrewed during load work that screws up my harmonics, and wrecks my test?

If it was human I'd have divorced it, or whupt its ass by now.

So in conclusion I have learned if it ain't broke dont fix it.
Unless you can truly afford to purchase your reamer , buy custom dies, and enjoy beating your head against the wall...

LEAVE IT THE F@(< Alone !!

 

[Bc'z]

I suppose I could just screw the old barrel back on and solve all my problems except copper fouling.

 

[JFrank]

That Pisses a fella off fo shore...

my old Attorney use to say when in doubt- (do nothing....) so as the song goes , put the lime in the coconut then call me in the morning.

 

[MikeMcCasland]

Time for a Giraud.

 

[Texas10]

I suppose I could just screw the old barrel back on and solve all my problems except copper fouling.

What would happen if you went back to neck sizing only?

 

[Bc'z]

Time for a Giraud.

Thanks Mike I needed a good chuckle.
I only shoot about 1500-2000 rounds a year, generally getting 3-4 firings before needing to trim to length across all the calibers we have.

I've gotten a couple PM's from a couple well known and respected shooters on my sizing problem that I'll re read a couple times today and ponder my next step.
Options as I see them
1st, Wilson will hone the die for cost of return shipping as per our conversation.

2nd, purchase yet another die, custom of course. $$$$$$

3rd, Neck size my brass and to hell with FLS for this rifle. No costs incurred!

4th, put old barrel with unknown round count in a vice and start lapping, then put it back on. Just a time expense this route. Load work will be minimal to get tune back, lifespan will be unknown.

 

[Tommie]

How about a close-up photo of some once fired brass? Especially the web area. Should shed some light on the situation.

 

[Bc'z]

FLS on left, 1st firing on brass after FLS on rt.
Sorry photo isn't better protective lenses on phone is busted.

 

[Bc'z]

How about a close-up photo of some once fired brass? Especially the web area. Should shed some light on the situation.

a little better picture of fired 1x
While talking on phone with @SPJ , I took rcbs FL die and dropped case in die.
You could hear a audible metallic sound as brass neck bottomed out into neck sizing portion of die, brass has ever so slight wiggle room at base of die this point.
Wilson die will not let brass freely slide into it.
Measurements from new, sized w/Wilson,
1x fired.

 

[grovey]

@SPJ
I should've left the factory barrel on, sumbitch shot .25" groups religiously.
Just a bitch to get the copper out of it.
New barrel cleans in jiffy and refuses to copper foul.

I've fought over pressure with my lapua brass, as necks were to thick for new chamber.
Now I'm neck turning.

Now the difference of new chamber to the die dimensions, causing me to trim every firing.

This whole project has been a huge pain in the ass!!
And for what?
Frustration and futility?
Groups that are .25" bigger than I got with original barrel?
A freaking BOSS system that comes
unscrewed during load work that screws up my harmonics, and wrecks my test?

If it was human I'd have divorced it, or whupt its ass by now.

So in conclusion I have learned if it ain't broke dont fix it.
Unless you can truly afford to purchase your reamer , buy custom dies, and enjoy beating your head against the wall...

LEAVE IT THE F@(< Alone !!

I remember the original shooting tiny groups. Sorry to hear the new one is hard to keep in line.

 

[Bc'z]

2nd and 3rd firing measurements.
Shoulders stopped moving, web is the same.
I noticed sized neck is .0005 smaller on 3rd firing than 2and. Sized OAL stayed the same.
Brass still chambers effortlessly after 3 firings.
I might just keep on neck sizing this cartridge.

 

[Twicepop]

The 30-06 will continue to grow until it separates above the case web. The case has a large amount of body taper and only a 17 degree shoulder angle. It was designed for optimum ease of feeding under the worst of conditions with little to no regard to handloaders. The design goes back to 1903 and the case neck was shortened in 1906. Very few cases designed in that era exhibit traits that lead to maximum case longevity. It was an Americanized version of the 7/8MM Mauser basic ammo case only slightly longer. It shares the same 12mm rim diameter as the Mauser case design. The U.S. Government had to pay royalties to the Germans until sometime after the First World War ended because of patent infringements because the '03 Springfield was a rip-off the '98 Mauser design and used their same case design dimensions also.

 

[Bc'z]

The 30-06 will continue to grow until it separates above the case web. The case has a large amount of body taper and only a 17 degree shoulder angle. It was designed for optimum ease of feeding under the worst of conditions with little to no regard to handloaders. The design goes back to 1903 and the case neck was shortened in 1906. Very few cases designed in that era exhibit traits that lead to maximum case longevity. It was an Americanized version of the 7/8MM Mauser basic ammo case only slightly longer. It shares the same 12mm rim diameter as the Mauser case design. The U.S. Government had to pay royalties to the Germans until sometime after the First World War ended because of patent infringements because the '03 Springfield was a rip-off the '98 Mauser design and used their same case design dimensions also.

I've personally never experienced a case head separation and dont want to.
If I continue to use the Wilson die in it's current configuration case head separation is imminent.
The brass used today to troubleshoot my brass flow issue is the same brass I've been shooting in this rifle since new.
Data collected today shows the brass stopped moving after 3 consecutive firings with no annealing.