Another disappointment at the Range.

[Sure Shot Mc Gee]

Had a little problem arise at the Range today. I've been using S.B. dies to reload my 300 sav with. Today again it happen >Another case separation!! Again just above the shells base it cracked completely around the entire circumference of the shell. This is the second time I've encountered this experience. At first I thought it could be from a oversize chamber. But two different rifles. No >that can't be the reason. My questions: When using a SB resizer. Will doing so cut the amount of reloadings down on a shell? I've gotten as many as 10-15 reloadings using a FL resizer. It appears not so from a S.B. resizer. Have others incurred the same experience with their rifles and SB dies? Or is there another reason for the case separations? I'll try to stay on point and as quick as I can answer your questions. Appreciate the help fellows. Any and all comments are welcome.

[math teacher]

Small base dies reduce the case more than standard dies, thus working the brass more. You did not say how many times these cases have been reloaded, but you will not get as long a case life with small base dies. I am not sure you need small base dies in this instance. I have always used standard dies loading for the 300 Savage in my two Savage 99s without any problems.

[iraiam]

Do you have to cut much off the length after you re-size with the Small Base die? If so, that's probably an indication that your cases are not going to last long, The longer the re-sizing die makes your cases the thinner the brass wall is becoming.

The longest case life I have achieved has been with only doing neck sizing after the case has been fired in a bolt action rifle.

I have had problems with a Small Base resizing die before, but it wasn't a case separation, In my case the extractor on a Remington 721 would not grab the groove until after it was fired, Remington has the small spring steel extractor in the face of the bolt, they worked fine in a Ruger M77, which has a big "claw" for an extractor.

[jimbob86]

The longest case life I have achieved has been with only doing neck sizing after the case has been fired in a bolt action rifle.

+1.

[mrawesome22]

Too much shoulder set back.


sudo passwd root

[Sure Shot Mc Gee]

math teacher: I'd say those W/W cases had about 4-5 reloading at the most. They were at one time early on annealed because of that shoulder and short neck they have. Other than that there were no other special treatment done to them besides their being resized and shot. I do run my shells up on powder charge weights. Been using 3031 maybe its time to switch. I just don't know? Being 300 brass is getting costly and hard to find I suppose I could make my future brass from 308 Federal's and just pitch them after a couple of firings. Picked-up allot of 308 brass this last year left behind on my club Range. Perhaps it was I good thing I did. Oops. Forgot to answer your question regarding why I don't use FL dies. I primarily use RCBS F.L. dies but that last little bit of shell they can't seem to resize and it stiffens the 300 lever closure at the very end of its cycle lock-up just annoys me. So thus the S.B come into the picture to help resolve that situation.

[Sure Shot Mc Gee]

iraiam: The only time was when they were first used. (new) And trimed very little at that. Just enough to keep them all at the same length as to help in the seating stage.

This is a statement that needs a little clarity. Their trimmed to Max tolerance acceptable the first time. Which doesn't take much turning of the trimmer handle to get there on brand new brass. Sorry about that guys. I guess we can chalk this one up to: oops Thinking one way and writing it down another. _

[Sure Shot Mc Gee]

mrawesome22:

Too much shoulder set back.

Not quite sure what you mean? When I set my resizer dies up for the press I have. It's a shade less than the 1/4 turn backed off that's suggested> (Die is set when the ram is fully extended in its most upwards position.) I think that's when a shells shoulder is set to be what is (acceptable.) Am I correct there Sir? or not?

[HiBC]

The first thing I would do is check all your brass with "the paper clip trick"

Straighten a paper clip,and bend maybe 1/8 in or so of a 90 deg bend on the end,so it looks like a short legged allen wrench..

Use that to feel for a stretch ring on the inside of your brass,right where they are failing.

If you find the ring,cull them out,or you will be chasing your tail.It wont matter that you are doing things right if the brass is already about to fail.

You mentioned annealing the cases.No disrespect intended,I don't know how you do things..any chance you annealed more than the necks?

So you trim?over length brass might give you that resistance at lockup,as could crimp bulge,etc.

IMO,it is useful to have a means to measure how much you set your shoulder back when you resize.Hornady makes a caliper attachment,or you can use a bushing type case gage (I measure the change with the bushing gage and calipers).

I'd guess .003 or .004 would be good..002 is good in a bolt gun.

Good luck!

[Sure Shot Mc Gee]

HiBC:

The first thing I would do is check all your brass with "the paper clip trick"

That's a new trick. One I've never heard about. I'll give it a try and see.

any chance you annealed more than the necks?

As far as I know. I don't think the heat got that low on the shell. Maybe a bit just south of its neck 1/4" or less. But that's about all. I'm pretty watchful when doing that.

So you trim?over length brass might give you that resistance at lockup,as could crimp bulge,etc.

Yep sure do trim. After their very first resizing I cut the Max amount allowable off. That way they all grow the same hopefully. There after their length is checked in a Trim die prior to resizing again. I have noticed that my trim die does seem to push the shoulder down a little more so than the S.B. die does. But I fugure the S.B. resizer will bring it back to tolerance.
As you know 300 brass is really finicky concerning its crimp. So I hardly apply any. And if there is any. Its just enough to (lightly) push the brass up against its bullet at best.

caliper attachment,or you can use a bushing type case gage

I'll have to check into that.

What I should do is have the barrel reamed to a 308. 300 is a great deer cartridge. But gee it sure can frustrate a guy in its reloading.

[HiBC]

On changing your 99 to a 308.

Its your rifle,your choice,but on a fine old rifle like a 99,I'd be very reluctant to make any changes from original.

I am not a 99 expert,but,for the problem you are having,I do not think it will help to step up to a 308.

The .308 operates at a higher pressure.If the problem has anything to do with a little extra stretch likely from a rear lockup action,the problem may get worse.

I do not think the short neck of the 300 has anything to do with head separations.

What happens:The firing pin strike drives the cartridge forward till it stops on the shoulder.

At ignition,pressure increases,case expands and grips chamber wall.It grips the chamber wall,and the front part of the case,all that is supported by the chamber,stays put

As the pressure peaks,the case head is blown back to the bolt face.All the stretch occurs approximately at the mouth of the chamber,where you get the stretch ring.

The 99 is a good ,strong action,but it may be that it allows a little more stretch than a bolt gun.I do not know.

The usual problem,when resizing,the shoulder gets set back farther than necessary.This means each shot,that stretch ring area has to stretch more than necessary,shortening brass life.By setting the shoulder back,we duplicate the problem of having a rifle with excessive headspace,even though the rifle is fine,the ammo is short.

Ideally,we size just enough so we get reliable chambering,and maybe .001 or .002 for margin of error,but some dies and shellholders may set back .007 or .008.

Here is another question:Are you pushing the hot side on your reloads?

If so,we can talk about how that is part of the problem.

[HiBC]

http://www.varmintal.com/a243zold.htm

Now,this study is about chamber finish.I would not worry about your chamber finish,thats not why I posted this.If you study the pics,you can see how the stretch ring occurs.

Once again,on annealing the cases,if there is any chance heat got past the shoulders,scroll down to the bottom of the article and see what he says about an annealed case head.

And,actually,a SB die would tend to offset(shear)the case body at the problem area.If the problem came with the change to a SB die,:-),it might mean something

[Sure Shot Mc Gee]

HiBC

On changing your 99 to a 308.

No that was one of those empty threats I make when I'm disgusted with something. This rifle I shoot is in pretty decent shape never would I ever re-chamber it. Maybe a new 250-3000th barrel I'd like. But no reaming job on its original.

Here is another question:Are you pushing the hot side on your reloads?

Is there any other way. Yup all my bolt rifles I push their ammo to the Max and in some cases a little bit beyond like my (270-25-06 is) But this older 300 and a 32 special I have won't tolerate my aggressive behavior. So their baby'ied some with reduced loads. Not much but some.

And,actually,a SB die would tend to offset(shear)the case body at the problem area.

That makes sense. Its probably the weakest area of all on a cartridge case. I always thought cases were stretched from their base forward in their manufacturing process? But I'm not sure?

If the problem came with the change to a SB die,:-),it might mean something

Oh ya. Both times (S.B.) they were used when I had base separations.

[GeauxTide]

Sounds like your cases are expanding from head to shoulder too much. Don't recall seeing what your charges are in relation to max. You might consider putting a dime between your shell holder and the die when you tighten down. If you can chamber easily after, go to a penny, then a nickel.

[HiBC]

While I concur with GeauTide's idea about using a shim of some sort to set a clearance between the die body and the shellholder,I suggest using a set of feeler gages as an alternative to coins.

[reloader28]

^^^^
These gents are right. Its called partial sizing.
I have a 243 that does the same thing if I dont partial size or neck size.
If I partial size, I get MANY reloads from them. FL sizing this gun and they come apart the second time.

I made a set of thin washers to put under the die since its set up for FL sizing. Then to partial size I use 2 or 3 small washers between the die and press. Leaves it more versatile.

[Sure Shot Mc Gee]

So reloader28 & GeauxTide. Your threads read, you think by adding more free space between the base of the die and its shell holder at set-up time may help stop head separations? Here's how I have my resizer die set. Its mounted to its closes point to the shell holder as I can get it. I mean you barely can see any light between them. I always thought the more shell you can get up into the die, the better the resizing job is. Am I wrong in my thinking? Why?

[Sure Shot Mc Gee]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

For those who have mentioned wanting to know. This is the loading I use in my 300 Savage:

37.3 gr. IMR of 3031 under a 170 gr. Winchester Silver tip in a W/W case with a Federal LR primer.

[reloader28]

Sure Shot,
Thats how you would normally set up a die or even tighter for a tad more cam over.

But,f you put some more space in between the die and press, it doesnt push the shoulder back down as much. It leaves the length from the base to shoulder longer. If the extra length fits fine in your gun, it takes some of the stress off the next time you shoot that case because its already long.

BUT, this is now sized for THAT gun. If you try to put it in another gun it may not fit because of the length.

[oldmanFCSA]

I agree - too much shoulder set-back.

Done correctly - one of our FCSA shooters has over 50 reloadings of same lot of match brass - must anneal every time and only push shoulder back 0.002" max !

[Sure Shot Mc Gee]

reloader28 & oldmanFCSA I think I see your point. By increasing the dies gap between it and its shell holder. The shell doesn't grow as much during its firing. Thus eliminating some of my shells (work hardening) near its base. What do you guys suggest is a reasonable starting gap measurement? I've read what GeauxTide suggested which is a great suggestion. (pocket change) But I'm fortunate to have an old set of tappet feeler gauges handy. Which I think would work a bit better for me (more of a precise adjustment in either direction can be had in there using)


mrawesome22: looks like your ahead of the curve this time but not by much. lol

[oldmanFCSA]

On a fired pc of brass, set shoulder back 0.002"max to eliminate case head separation.
Your die setup is forcing shoulder back too far.
What happens:
Firing pin pushes case forward in chamber.
Light primer strike causes slow ignition.
Case expands at shoulder and neck grabbing case wall against chamber wall.
Unsupported case head stretches back against bolt face.
Weakest portion of case is stretched just above case head.
Repeated practice willseparate case head as you have descibed.

Also, primers may be severely flattened with moderate loads by to short a case.

[oldmanFCSA]

Small Base dies are sometimes used for reloading for lever-action or semi-auto rifles to assist in chambering a round.
These dies only squeeze the lower 1/4 of case smaller in diameter to ease chambering.
Improper die setup with ANY die will cause case head separation, do not blame S.B. Dies.
Screwing a die down to shellholder is WRONG - I don't care what reloading manual says - do it right for YOUR RIFLE - not for the masses.

[tobnpr]

I've only been reloading for three years, but have done about 8,000 large cal centerfire rounds on my LNL over that time...

Never gotten less than a dozen firings (bolt guns) from my brass, and usually I set them aside "just because", not because they've failed. When they do, it's a cracked neck...never had a case separation.

I FL size every case, trim only when necessary (which is usually only once during the life of the brass), and just set the press to cam over hard on the die. This most always results in .002 shoulder bump from the fireformed cases.

Every reloader should have a headspace gauge to check shoulder bump...

[Sure Shot Mc Gee]

I believe this is what you fellows suggested I purchase.

L.E. Wilson Case Length Headspace Gage 300 Savage

My question now: would I be better off buying this Wilson HS/G? or a different manufactures model? (for ease of using)

P.Script: I do have a good stainless caliper here for measuring accurately.