2nd Broken Lapua Case for .223

[GunnyUSMC]

What are you doing to the cases to make them so black? Is there a problem with your AMP. Properly annealed cases should never turn real dark. Are you annealing with traces of lube on them.

I started to not clean my brass based on experience shared by fellow shooters. Previously i used a flame based annealer and recently upgraded to the AMP. in both scenarios, the necks came out dark, especially after sizing and not really sure why. I anneal after firing so there is no lube on them at all.

Your at 25.3??? The max fps in the manual is 100 fps less than you have. Where did you get your max. charge suggested from?

I worked my way up to that load. I have had the mindset from ELR to 1) push heavy bullets fast and 2) fill the case to a minimum of 90% which is what my goal was with the Berger 85.5. My freebore allows me to push the bullet out so i dont have to crush the powder. I get really good performance with this load at 600yds and 800yds. This is the load that my daughter uses to consistently shoot in the mid 580s for FClass with her last local match performance at 589 16x on a home built FTR rifle. My original testing got me to a max of 25.5gr CFE223 but i backed it off a little to 25gr CFE223 and an average MV of 2840. It is a little hot but before this separation problem, there were no other signs of over pressure.

I know Varget would be the perfect powder but was just trying to make the best of the powder i had on hand.

 

[GunnyUSMC]

Guys, this is a really great learning experience. Thanks for all the feedback.

I did have a chance to analyze my cases from the same batch as the one that separated and the results were interesting.

First of all, i looked for a ring around the middle of the case as recommended and found a handful that showed the ring. I made a tool to scrape the inside of those cases and did find a ridge as explained and expected. I then took my bore scope and that really told the story. See below:

 

[Kracken McGraw]

Guys, this is a really great learning experience. Thanks for all the feedback.

I did have a chance to analyze my cases from the same batch as the one that separated and the results were interesting.

First of all, i looked for a ring around the middle of the case as recommended and found a handful that showed the ring. I made a tool to scrape the inside of those cases and did find a ridge as explained and expected. I then took my bore scope and that really told the story. See below:

View attachment 1628699View attachment 1628700View attachment 1628701View attachment 1628702

It makes you wonder how the brass gives up on such a clean line like that.

 

[FNSafari]

The wonderful world of the internet and well meaning others sharing info to help someone else out. Great stuff !!

 

[GunnyUSMC]

I would clean necks. Many chemicals left after firing. View attachment 1628724

From AMT-

I had a short conversation with Alex at AMP regarding the use of dry lube for neck sizing. See Alex's response below. Note that his reference to lube is in regards to using the dry lube on the neck only. The point for this conversation though is that he does not clean his brass.

"We actually don’t lube, and we don’t clean either. We do brush inside the necks with a dry nylon bore brush on a lathe at 400 RPM. One pass is enough. That doesn’t remove the carbon, but it does smooth it out. We get very consistent seating forces."​

When others were sharing that they dont clean, I was on the fence. I have tumbled with walnut and rice, i have wet tumbled with SS media (which provided pretty brass but was told it makes the brass TOO CLEAN). After this response from Alex, I was convinced that not cleaning my brass was something that needed to be considered.

 

[Webster]

Another thing I think is a contributing factor is all this talk of bumping the shoulder back. Do this and you are causing failure of the case. By "bumping" the shoulder, you are decreasing the headspace and causing the brass to stretch. When the cartridge is fired, it expands to fill the chamber. Keep doing this and the case will fail.
When you fire the cartridge, you have just performed the best resizing there can be, You've pressure formed the case to exactly fit your chamber. The headspace is perfect. All that's left to do is work the neck to accept the bullet.
Buy a neck sizer or a Lee Collet die and leave the case shoulder and body alone.

All the top shooters FL resize. Bumping the neck 0.002" does not cause cause failure. After firing a new case if you can close the bolt on it it doesn't have to be bumped. Keep sizing without bumping until the case will not spring back as much and there is a little resistance to closing the bolt. This length is the length you bump 0.002" from. I have been reloading for 50 years and never had case body or neck separation. I have over 20 reloads on my 6BR cases without a problem.

 

[jwv2001]

All the top shooters FL resize. Bumping the neck 0.002" does not cause cause failure. After firing a new case if you can close the bolt on it it doesn't have to be bumped. Keep sizing without bumping until the case will not spring back as much and there is a little resistance to closing the bolt.

This is getting tiring to keep repeating. Did you read the first post in this thread? The OP was annealing and bumping after every firing. In the above post, in your own words, you gave the same advice as I did only 72 posts too late.
I get it, you're trying to elevate yourself instead of answering the OP. Nobody cares how many years you've been loading. That doesn't make you right.

 

[Dgd6mm]

GUFFY IS BACK!

 

[Webster]

This is getting tiring to keep repeating. Did you read the first post in this thread? The OP was annealing and bumping after every firing. In the above post, in your own words, you gave the same advice as I did only 72 posts too late.
I get it, you're trying to elevate yourself instead of answering the OP. Nobody cares how many years you've been loading. That doesn't make you right.

To many replies. Eventually no-one cares what anyone says. I cannot read 76 replies and understand them before I reply. I think that's the reason the thread keeps going. It's an old problem. If anyone understood the cause it would take 1 reply and it's done. Will it reach 100 I don't know replies. I need a cup of coffee.

I assume guys know how to adjust dies and set back the shoulder the correct amount? Setup is not difficult. Some people cannot follow instructions. Just looked at several videos on case body seperation. All the video's point to a poor fit of the case in the chamber due to improper sizing. 99.9% of us never have this problem.

Your post #19 says that bumping the shoulder leads to case seperation. It does not if it's done properly. Also the case body does not get softened from annealing.