Recent Experience with Peterson Brass- Neck Breakage and Brittleness

[Veteran]

I have always had excellent results with Peterson Brass, but after 4-5 firings on my .300 WM, I am starting to see necks
tear, sever, and become cracked.

I annealed this brass every firing.

The reason I switched to Peterson was case head separations above the belt in 3 firings, on the other brands.

I bump the shoulders back .002 every time, and have been careful not to over exercise the sizing die into causing fatique above the belts which is where I had problems before. Now, I have had no more case head separations and not even the tell tale circular cracking that comes just before it separates. Instead on about 5 of 50 of my Peterson cases, I am seeing cracks, and neck severing as in the pictures attached.

I am shooting the Peterson .300 WM belted regular brass, not the long brass. I am lubing the bullet bases with graphite powder prior to placing them in the necks to seat them. I have spoken to Muddyboots and he has recommended I lube the case necks inside before seating with case lube. I will try that next. I also have the Peterson .300 WM longs but have not tried them yet.

Now, the rifle I am loading for and firing these in is not a regular bolt gun, instead it is a bit of an odd duck, the TC Encore with switchable barrels. So it is a breach loader with some tendency to possible head spacing issues.

I'd be interested in hearing of any similar experience with neck cracking and failures on Peterson or other brass.
See the attached pictures. I took all of these out of my tumbler this last go round and then when I inspected them,
found these issues. I will definitely check my breech and bore on the rifle for the severed neck which is missing on the one casing.
Just in case......, no pun intended.

Yeah, that one that is severed and missing the neck looks like I left it in the trimmer waaaaaayyyyyy too long......

Until it was waaaaaayyyyyy too short!

 

[PddPdd]

What is your annealing method/machine?

 

[Veteran]

I'm using Annealeez machine.

I use it for .338 LM, .300 WM,
and .308 as well. Have it timed for each cartridge.

 

[Bravo 4]

My first suspicion is your chamber may be on the big side (maybe even in neck clearance), especially when you mention having issues with other brass manufacturers. Compare a new case to a fired one, I think the brass is getting overworked.

 

[xsn10s]

What's the bullet and load?

 

[Pdyson]

I'm having zero issues with Peterson 300 and 7mm Mag brass. I love the stuff and rate it on par with alpha and Lapua. I over annealed once and the shoulder collapsed in the sizing die. But if you're getting splits I'd say it's possibly under annealed.

 

[Veteran]

What's the bullet and load?

150 gr sierra 2125, 81.3 gr. Magpro, 3.461 Coal, 3250 ish fps,

 

[xsn10s]

150 gr sierra 2125, 81.3 gr. Magpro, 3.461 Coal, 3250 ish fps,

Doesn't seem out of the ordinary except for the COL compared to Hodgdon's load data. Maybe have the chamber checked by TC.

 

[just_jon]

I would bet a tidy sum that you have excessive headspace. It looks like the primer in photo 6 has backed out a bit. I've had to deal with this problem with a few Encore barrels and it is an easy fix .

The first two videos below address how to measure headspace and the third addresses shimming the firing pin bushing to correct the problem.

 

[QuietTexan]

What is sized, loaded, and fired OD of the necks?

 

[MagnumManiac]

Many Reloader don't understand why or how necks split, it occurs just as the pressure is released and the brass is contracting away from the chamber wall. It is rarely caused by over-expansion, which is what most believe it is caused from.
Brittle circumferential cracking is caused by sizing the necks too much down then back up again, these are essentially stress fractures and annealing will not stop this. This is why I don't move my necks more than .0015" in ANY direction, even when using a mandrel. All of my dies have honed necks .0015" smaller than bullet seated OD, and my sizers are tapered and also altered to move necks the smallest possible amount while still maintaining good springback numbers.

Cheers.

 

[Veteran]

What is sized, loaded, and fired OD of the necks?

Fired O.D. of the necks is about .334 to .335 inches

I'm sizing with Redding dies using the 327 S type neck bushing.

I don't have any loaded right now, and haven't begun sizing any yet to measure the loaded O.D.

The other thing I thought of though is I have been using the FCD Lee Crimping die as well on the finished product.

It could be that my neck brass is getting over-worked through fatique even though its annealed.

Maybe for these specific bullets and the amount of friction in seating them using the 327 neck bushing,
I don't need any crimping. Its not an auto loader, they aren't hammer bullets, and so maybe crimping is a step too far for this particular magnum and bullet? I don't use mandrels or anything like that either.

Could be as Magnum Maniac says below, a lot of work out when the brass is crimped, expands to the chamber walls and collapses or rebounds back off of them? Metal fatique, cracking?

 

[Dirtrax]

What is the O.D. On a sized piece of brass? Looks to me like you may be squeezing them down more than needed. Add in crimping and the necks are over worked.

 

[Veteran]

What is the O.D. On a sized piece of brass? Looks to me like you may be squeezing them down more than needed. Add in crimping and the necks are over worked.

No loaded ones right now.