Cracked necks in 6.5 x 55 brass.

[JBS]

One more thought,

I showed the brass to the guy at a local gunshop and he instantly suggested that the headspace might be too large and said it probably wasn't safe to fire the gun until a gunsmith checks it out. Does that make sense?

Head space problems rarely cause this type of neck split. As I said, anneal your case necks at reloading # 2 or 3 and the problem will stop.

[Patrick Chadwick]

Aprayinbear, if you go to a gunsmith to have the headspace checked, he is
a) going to insert a SAAMI headspace gauge. Because he won't have the proper Swedish gauges,
b) tell you that the chamber swallows all the SAAMI gauges, the headspace is therefore excessive, and the rifle is therefore unsafe,
c) charge you for this misleading information.

The truth about Swedish rifles is - they were not made to SAAMI specs. SAAMI was set up in 1926, long after almost all M96s were made. This has been pointed out over and over again. Just check out this reference:

http://dutchman.rebooty.com/headspace.html

"dutchman" is a forum member, so I will save repeating what he has explained so clearly. After you have digested that, you will understand why it is a good idea to necksize your brass.
And your local gunshop guy is obviously not a milsurp expert.

But don't worry - be happy. We're here to sort it out!

Patrick

[Patrick Chadwick]

Duggaboy wrote "Also, I see little benefit in just neck sizing a military gun which is made loose anyway."

The loose chambering (by SAAMI standards - just perfect by Swedish standards) is exactly WHY it is a good idea to only neck size the cases. Full-length resizing, with dies made to SAAMI standards, causes a heavy reworking of the brass, with resulting early failure.

This may seem iconoclastic to the gauge-faithful, but after the first firing the case has expanded and lengthened to fit the chamber. So gauged headspace is completely academic IF you only necksize the cases AND only fire them in the same rifle.

Patrick

[aprayinbear]

Thanks for all the suggestions and info!

Here's what I've decided to try. First, I sorted through the remaining Winchester brass (when I had my reading glasses and very bright light) and I found five other cases with what might be the beginnings of shoulder/neck cracks. That leaves me with 11 good cases remaining. One thing I noticed was that these cases after shooting 2 times, were shorter then standard. So I full sized the remaining cases and trimmed to size. I also have a suspicion that there is a problem with my neck sizing die or the way I am using it. Next I tried my hand at annealing and was careful not to get the brass heated past a very pale red. I was careful to anneal only the neck and a portion of the shoulder. I wish I had some temper sticks, but am not sure where to find them.

Next, I'll load as before and examine the brass after shooting. I hate to change the load because I am getting good results with 35 grains of Varget. (see target below.... 5 shot groups slightly under 1" at 60 yards with open sights and my old eyes.)



And finally, I'll buy some more dependable brass like Lapua. I'd also like to try some reduced loads with cast bullets for plinking and target shooting (that is what I do with my 7.62 x 54r and the brass lasts and lasts.)

I really like my rifle and want to keep shooting it, but #1 I want to be safe. Does this sound reasonable?

Thanks again for all you thoughts, tips and support!

aprayinbear

[Patrick Chadwick]

Aprayinbear, you wrote "I also have a suspicion that there is a problem with my neck sizing die or the way I am using it."
That is why I suggested the lube-line test. Because the Swedish military chamber is a touch longer than a SAAMI standard, a SAAMI-conform necksizer set up in the usual fashion (die just touching shell holder when the ram is at the top) may, in fact, be pushing back the neck of a case fired in an M96.

For your next resizing, try backing off the neck sizer about half a turn. This leaves a small ring at the start of the neck, just above the shoulder, that is not resized. You can see it from the varying reflection if you move the case around in the light (or more easily with the lubeline test).

This unsized ring has two postive features:
1) The shoulder is completely untouched, so you get optimum seating of the cartridge in the chamber - better than with a full-sized case.
2) The unsized ring helps to center the neck in the neck section of the chamber - which helps accuracy.

As to accuracy, the target you posted shows an excellent group. The fact that it is narrower than tall is typical for open sights, as it is comparatively easy to center the sight horizontally, thanks to the left-right symmetry. But the vertical position does not have a symmetrical picture, so vertical variation is more pronounced.
Add to that non-teenage eyeballs, with perhaps some astigmatism, and what you have posted is probably the best you can do with open sights.

If that was my rifle, I would say that the load is perfect (judging by the width of the group). At 60 yards that vertical variation is largely a sights + eyeball effect. So get proper shooting glasses (if you have not already done so).

A last check: what hold are you using. If it is the 6 o'clock hold, then you need a higher foresight blade. These are readily available and acceptable for competition shooting as long as they have the same profile, as many/most milsurps of that vintage were set up for 300 meters or so as the minimum distance. A 1/8" / 3mm higher blade gets you in the center at short ranges with the backsight leaf off the sight base, so that you have room for adjustment.

On the other hand, if you have been aiming at the center, then a 6 o'clock hold will put the shots firmly in the 10 at 100 yards without making any other changes!

Summarizing: load and rifle are good. Shooter is good, but maybe better with shooting spectacles. Higher foresight blade advised. Back off necksizer 1/2 turn. Bin the whole batch of that dubious brass.

Good shooting!

Patrick

[jmoore]

Mr. Chadwick, what can I add to that except that I CAN'T add to it! Wow!

[aprayinbear]

Many thanks for taking the time to walk me through this. To be honest, I live in an area where everyone hunts, but almost no one shoots for fun. That means no reloaders, very few marksmen and very few clubs. So I go by the seat of my pants and read everything I can.

Your advice seems bang on! I'll definitely follow your advice with the neck sizing die, and about the front sight. I'd thought about a set of Mojo sights, but I'm sure that would disqualify me if I ever try to shoot in a milsurp match. I wouldn't want to be 21 again, but I sure wouldn't mind having my 21 year old eyes again.

Patrick.... I have one last question. The Lee manual says that with 120 grain Sierra Match Kings and 35 grains of Varget the Min. OAL should be 3.00. That's almost no bite for that small bullet. I'd heard it said that the bullet should be seated as deep as the width of the caliber beyond the boattail or in this case .264 bbt. But that makes oal approx. 2.95 . Is that safe?

What Are Your Thoughts?

[duckcreekdick]

Just for curiosity, I'd mike the neck I.D. of a fired case and then mike the neck I.D. of a neck sized case with the expander ball assy. removed. This will give you an idea of how much you are reducing the diameter and how you are working the brass in the neck. Compare the neck I.D. of a sized case w/o expander ball with the diameter of the expander ball. If you find a great amount of difference (more than the couple of thousandths needed to hold the bullet firmly in the finished cartridge), I'd suspect the reloading dies.

[duggaboy]

Gunner man: I have not seen cracks like these either.

[gunner]

Duggaboy, in a Swede they are normaly not there except you have bad cases and or the sizing isnt correct. Patrick wrote it the best.

Regards

Gunner