I just got my Lee dies for the 8mm Mauser and loaded my first rounds from once fired factory (S&B) brass. When I measured it (after sizing), the cases were .015 over max length. When I measured the loaded S&B ammo, the brass length was at absolute book maximum.

What that means is that in order to trim to "trim to" length (.010 under max) I had to take off .025 inch! That's the most brass I've ever shaved off a round.

I know for a fact that I have no headspace problems (had it checked) and my primer pockets are tight. I lubed the inside of the case necks before sizing, so I know that is not the problem.

Do I have a problem? If after the next firing and sizing, I still exceed max. I might just throw that batch of brass away. All that excess brass has to be weakening my cases somewhere.

quote:

Do I have a problem?

not necessarily as you didn't know the brass length prior to the first firing.....

Fire them again and see where you wind up.

Stretching occurs 2 ways.
1. Stretching the length to fill up the chamber when the ammo is shorter than the chamber. Even when the chamber is correct the ammo is going to be shorter. There are ways to gauge the ammo such as the Stony Point now Hornady tool or one of the case headspace gauges made by Wilson and Forster.
Check new ammo headspace before firing and both headspace and length after firing.

2. Next way a case stretches is diametrally- it get fatter when fired - please bear with me here.
The Diameter of the chamber has to be larger than the ammo. Some times the chamber can grossly larger than the ammo.
Make a chamber cast of your chamber and measure it.
Next is check your cases for diameter (pressure ring and shoulder dia) and length before and after firing the factory ammo. Especially the length after firing. Often firing makes the brass SHORTER BECAUSE IT HAD TO EXPAND TO FIT THE CHAMBER DIAMETRALLY. This means it stretched diametrally.

3.Take a case that you have written down the length for and size it without the expander in the die. Note any length change. Size about 10 cases like this and you will see a trend. The cases get longer when sized.
Then put the neck expander in the die and size some known length cases. Note that they get longer when sized. A really tight die will make them longer than a die that is just small enough to make the fit your chamber.
A neck sizer will not change the case lenght much.

Now what to do - here are several.

A. First your chamber is about .040 (1 mm) longer than the max ammo. You can verify this with a chamber cast. So trimming is not quite the emergency you might think.
B. Partial FL sizing of your brass may may help.
But you might have a hard time closing the bolt if you don't size enough.
C. Larger diameter harder brass will not stretch as much. But you never know until after you have bought it.
D. Neck sizing only may minimize your stretching (we can talk more about this in a later post)
E. Don't get too excited, you cases may quit stretching so much in subsequent firings especially if you stick with starting loads.
I suspect the S&B loads are loaded to European specs and are much higher pressure than American ammo.

After all of this there is a goo chance this is a combination of your ammo, you chamber and your sizing die.

From my experience the Lee dies are a very close match to RCBS dies internally. This leaves your rifle chamber diameter as a likely culprit. I have a Turk 98 with tight headspace but large diameter chamber.

If you still have any fired but unsized brass you can determine where some of the variables are. If not fire some of the cases the second time and see what they do lengthwise.

X.The stretching will probably slow down some.
Y. You will learn somthing
Z. You Mauser chamber is was longer at the case mouth than you suspect.

ZZ. To check your chamber length do this.
Trim a fired 30/06 or 270 case about .060 longer than your chamber.

ZZZ. Then full length size it.
ZZZZ Take the guts out of your Mauser bolt.Try to chamber the sized case. It will not chamber.
ZZZZZ Trim some more in .005 steps.
ZZZZZZ Eventually you will be able to chamber it. Though it may take some force. Look at the end of the case to see if it is being crimped by the end of the chamber.
ZZZZZZZ Trim in .001 increments until the 30-06 case will just chamber with a little friction at the case mouth. You will find it way longer than your ammo and your book.

1. Yes excessive stretching is not good but it may slow down and there are ways to mitigate it.
2. You need to find out what is causing it
3. If it is the chamber you may have to minimize it but live with it.
3. If it is the die you might minimize it or change it.
4. If it is only the brass use different brass but don't be surprise if other brands of brass do the same thing.
I will be glad to take your S&B brass just for testing purposes.
5. Your chamber will function with long brass. If you find out how long the chamber is you will know how long the brass can be.

Well, I'm headed for the range today. I'll shoot my reloads and see how much stretch I get. If it continues, I'll simply limit my number of trimmings to two before throwing the brass away.

Could be a function of the S&B brass, or atleast that lot. I have used PMC brass in 22/250 and 270 and got necks that grew by that much on first firing, I trimmed to max length and reloaded and the severe stretching stopped, I still shoot some off the 22/250 but it's about time to toss it, shows 7 loadings on lid.

Do you lube your loaded cartridges? That should stop further stretching.

What is the possibility of the bolt bearing unevenly on the locking lugs? Wouldn't that have a 'flexi-action' effect?

There is an unconventional way to limit stretching. That would depend on the chamber design. If there is a sharp step at the mouth to throat area of the chamber, the case can be made to 'headspace' on the case mouth. If there is a chamfer, it will jam the mouth into the throat, causing pressure spikes! I can do it in one of my Lee Enfield’s but not the other.
It will not work with crimping!

Have you looked into RCBS's X resizing die? It's marketed to stop case stretch.

quote:

Originally posted by GAHUNTER:
Well, I'm headed for the range today. I'll shoot my reloads and see how much stretch I get. If it continues, I'll simply limit my number of trimmings to two before throwing the brass away.

Horrible waste of brass and for the price of the brass you will throw away you can get a neck size die which is the best solution. Second is the RCBS X-die if you feel the need to FL size yor cases. I use both and haven'had any case stretch problems with the 8mm since.

Larry Gibson

Larry is right.
The redding Type s bushing die for the .308 Win can be used for about 40 cartridges with the right bushing - the 8X57 included.

Best I can tell it will handle all of these rounds by changing the bushings. In some case the same bushing will work with multiple rounds of the same caliber. Just adjust the die depth.

.22 High Power
.219 Zipper
.22-250 Rem.
.220 Swift
.243 Win
6mm Rem
.25-35 Win.
.25 Remington
.250 Savage
.257 Roberts
.25-06 Rem.
.260 Rem
6.5 Jap
6.5X52 Carcano
6.5X53R Dutch
6.5X54 MS
6.5X55 Swedish Mauser
6.5-06
.270 Win
7mm Waters
7X57 Mauser
.280 Remington
7X64
.30-30 Win
.30 Remington
.30-40 Krag
.308 Win
.303 British
.303 Savage
7.65X53 Mauser
.32 Win Special
.32-40 Win
8X57 Mauser


Might work with:
.338 Federal
.338-06

Does not work with:
7.62X54R
7.5X55 Swiss Schmidt-Rubin
.35 Remington
.358 Win

Well, I think I found the culprit in the S&B factory loads. Today I took my chrono with me to the range and my son and I shot and chronographed a variety of ammo. The S&B was the hottest by far, at 2760 fps. With a 196-grain bullet -- that's cookin', folks!!

My handloads (46 grains of IMR 4064, 195-grain Hornady), loaded in the trimmed S&B brass chronoed a more sensible 2520 fps. Best of all, the brass did not stretch beyond max length (so I came home and reloaded it )

I also shot a bunch of Winchester Power Point factory loads (2250 fps) and Privi Partizan factory loads (196-grain softs @ 2200 even) Neither brand stretched beyond max after firing and resizing.

One thing I can say for Sellier and Bellot, however: even though they load rediculously hot, their brass is excellent stuff with some of the tightest primer pockets I have ever reloaded, even after slinging those super hot bullets down range.

BTW, I had a second box of S&B factory ammo that reacted just like the fist, expanding .012-.015 beyond max with just one firing. I think their load is just too dang hot!

Interesting report. What model rifle and barrel length did you get that velocity from?

I have a Turk with a large diameter chamber but tight headspace that lets S&B really swell up.
The Persian Mausers shoot it like normal ammo. The pressure ring looks normal. I was always more suspicious of the Hansen 8X57 that I had. It is not marked Privi Partisan. It has an IK and 8X57JS on the headstamp and the primers leaked with several cases out of 140 rounds.
Appearance of the pressure ring looked normal but the primers were leaking.

It's a Model 98, 1943 stamped on the reciever. Non-matching bolt, but go-gauge says it's headspace is spot on.

Dark bore, but it shoots pretty dang good for a 70-year-old rifle. I spent about three days soaking be bore in copper solvent, but never was able to get a clean patch.

I would not be as surprised by your velocity coming from one of the 29" barreled rifles but that is pretty speedy for a K98.

quote:

Originally posted by SR4759:


2. Next way a case stretches is diametrally- it get fatter when fired - please bear with me here.
The Diameter of the chamber has to be larger than the ammo.

SR4759,
How do RCBS X dies work?

quote:

Originally posted by tnekkcc:

quote:

Originally posted by SR4759:


2. Next way a case stretches is diametrally- it get fatter when fired - please bear with me here.
The Diameter of the chamber has to be larger than the ammo.

SR4759,
How do RCBS X dies work?

tnekkcc,
I do not own an X die. The explanations of how they work do not see to be reasonable when you have a very large chamber.
I have read that the X die has an internal shoulder at the case mouth that pushes the case mouth back to an in spec length condition when FL sizing. My reservation is with a case that has been stretched by multiple firings eventually has enough brass that it has to be pushed somewhere. I think this might eventually result in buckling the case inward.
I am not sure I will ever own an X die. I have too many other reloading "impediments" to play with.

Today, I screwed up and trimmed and chamfered a batch of .223 brass before I sized it.

So then I started sizing perfect 1.750".

The Redding FL "S" die .246" bushing with no stem stretches the brass to 1.758"....stretch = .008"

The Forster FL die with neck honed to .246" and no stem stretches the brass to 1.755"....stretch =.005"

The max length is 1.760"....stretch .010" between trims


At this rate I would have to trim after every firing.

This is enough to make me order a custom die from Niel Jones.

That brass might have come from an AR15.
Maybe my Ruger #1V has a tighter chamber.

tnekkcc

Do yourself a favor and get the RCBS X-die (regular one not the SB) in .223. I get no stretch at all with any cartridge I size in an X-Die. They work because; cases "stretch" when they are sized in a regular FL die because the sides are pressed in first as the case goes into the die. In the web area where the case has streteched the most the brass is not compressed back to it's original form but takes the path of least resistance and pushes the case body forward. The shoulder is set back slightly as the FL sizing is completed and the neck is a little longer.

With the X-die the decapping rod is a snug fit to the inside of the sized neck and it has a shoulder on it. The shoulder is adjusted to the OAL of the case before firing, or to whatever length you want it. As the case is just being FL sized the case mouth buts up against this shoulder. This prevents the case from being pushed forward and elongating. Thus no triming. The X-Die will not shorten cases that are already too long. Those will still have to be trimmed one more time.

I have X-dies for several cartridges and no longer have case stretch or have to trim any case after FL sizing in them.

Larry Gibson

OK, Larry, I'm sold.
I'll get a 223 X die.

So Larry, how far do you have to drive to get a long range?
Wenatchee?

My getting 1" high at 100 yards at the Issaquah range is not working out on the big game at 625 yards.

quote:

Originally posted by tnekkcc:
OK, Larry, I'm sold.
I'll get a 223 X die.

So Larry, how far do you have to drive to get a long range?
Wenatchee?

My getting 1" high at 100 yards at the Issaquah range is not working out on the big game at 625 yards.

I live 2 miles from Tacoma Rifle and Revolver Club (TRRC) or about 10 minutes driving on city/urban streets. The main range is always a 200 yard range (target stands at 25, 50, 100 and 200 yards) and during matches, practices or shoots it is a 600 yard range. I'm also only a couple hours away by freeway from DNR land over by Ellensburg where you can do some pretty long range shooting. I also travel to eastern Oregon quite a bit as I've got property there. On one rannch we shoot to 2,000 hards with .50 cal rifles.

For longer range rifles I zero poa=poi at 200 yards. I then can hold over for longer range but prefer to adjust the elevation as that has proven to be the more accurate method. All of my serious rifles have scopes with repeatable elevation adjustments and turrets that can be marked for the load used at the loacation it is used at.

I've a couple ballistic computer programs that give excellent correction information for longer and shorter ranges. However it is critical that you input accurate data on the firearm (height of scope above bore is critical) and load (actual muzzle velocity and actual BC are also critical) if the adjustments are going to be correct. This is where the use of a chronograph and particularly the Oehler M43 come in real handy becuase i get the actual muzzle velocity and measure the actual BC. These programs will also correct for different elevation and conditions I might go to. So far they have proven to be spot on with various cartridges out to 1000 yards. It is also important to know what the real adjustment value is of the scopes adjustments so that if you need to go up 12.5 moa you really are going up 12.5 moa.

I also have a Leupold RX-IV range finder. I have found the TBR to give fairly accurate corrections out to 600 yards, at least accurate enough for big game hunting. Having the elevation turret marked for the computerized correction and then having the TBR correcting for uphill/downhill has taken a lot of the guess work out of it. Leaves much more time to second guess the wind and make an accurate shot. Knowing the range is a hell of a lot better than guessing!

Larry Gibson

Someone paid for a membership for me in 2000 at the Tacoma Sportsman's Club in Puyallup. I used the public 200y range there once, and usually used the private 100 yard range.

That is a long drive.

I can reach the Issaquah range in 30~40 minutes.
They have 100y and 50y targets.

I am looking at the Wenatchee 600 yard range as a 3 hour drive.

I have the Lecia 1200 yard pocket model range finder. Deer fall down dead at 400, 400, and 500 yards. Elk at 650 yards just look at me and then walk away.
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Today's experiments:
.223 brass re sized in Redding FL "S" die with .246" bushing, trimmed to 1.750" and chamfered.

20 gr bulk 4895 [behaves like H322] 60 gr HNDY TAP bullet moly 2.6" OAL.

When fired, case shortens to 1.743"
When sized with Forster FL .246" honed neck die, stretches to 1.7475"
When sized with "S" die, lengthens to 1.748"

reloading with 25 gr, fires, shortens to 1.7475"
When sized with Forster, 1.752"
When sized with "S", 1.753"

Trimming to 1.7495"
reloading with 22.5 gr, fires, 1.7435"
Forster die 1.7485"
"S" die 1.7495"
reloading with 22.5 gr, fires, 1.7445"
Forster die 1.7485"
"S" die 1.7495"
reloading with 22.5 gr, fires, 1.7445"
skip the Forster
"S" die 1.7505"

20 gr = 34 kpsi
22.5 gr = 47 kpsi
25 gr = 66k kpsi

What does it all mean?
The case shortens when fired.
The case lengthens when sized.
The tight die lengthens more then the loose die.
The loose die before the tight die lengthens less then using the tight die first.
The hot load makes .003" net growth.
The wimpy load has no net growth.
The medium load has no growth if loose die first.
The medium load has .001" growth if tight die first.

tnekkcc

I've been to the Tacoma Sportman's a few times. Never really tripped my trigger. I was a Member of the Paul Bunyon Club for quite a few years but since TRRC is so close I just mostly go there. I do feel your pain about having to deive so far. My favorite haunts are the wide open high desert spaces. I got addicted to them from living in NE Oregon for 18 years.

"I have the Lecia 1200 yard pocket model range finder. Deer fall down dead at 400, 400, and 500 yards. Elk at 650 yards just look at me and then walk away."

Even the best of range finders has problems at 450+ yards in a lot of light conditions. Just not much reflectiveness to deer and elk. Deer seem to be a little more reflective as their hair lays smoother than an elks, particularly in winter. If I can read off the animal I try to pick something that may be more reflective at about the same range. Some days are stones though and they just walk away.

Read the direction for the X-dies carevully. I did not do the first sizing and trimming as the chamber necks are sufficiently long. I just adusted the die to the once fired cases. I use the .223 X-die for 6 different rifles now without having readjusted it.

Larry Gibson

That range finder works out to 1200 yards out of a car window. I only saw deer and antelope from the window.

It does not work as well looking through grass while crawling on my belly. One straw of grass that I can't even see gets in the way and the range reading may vary. I saw deer, antelope, and elk from my belly.

I was playing with it today, and tree branches in the way 300 yards out there are just as bad as grass 3 feet out there. I can see through the grass and trees, it is frustrating that the machine can't.

---------------------
Are those X dies just regular RCBS sizer dies with a stopper on the stem?

quote:

X Die Rifle Mandrel Assembly 10.98

How much initial trim?

The initial trim is what is getting me.
I did more experiments today, and I can run red hot with almost no growth using the Lee Collet die.

But first I need to get the 1500 round of AR15 fired brass to fit in my Ruger #1.