What am I doing wrong with sizing brass?

In my opinion just because it fits in a case gage does not indicate that your brass is headspaced to your chambers dimensions. Remember stacked tolerances.
I would try to adjust your full length resizing die to reduce the brass shoulder demensions by about -.002".
after making this adjustment see if your brass will chamber and your bolt will close. If it will not close easily scew your die in a little further and repeat the insertion proces until your brass cartride case will fit into your chamber and your bolt will easily close.
Once your properly headspace has been established you can load up just one round with primer,powder and bullet and see if it will fit entirely into your Sammi spec case gage as well as your rifle.
If you have a mind you can purchase the Redding(caliber spefic) body die as wellas the redding competition shell holder set and run all your brass through it. (this is what I use)
Additionally I was wondering what brand of brass that you are using andperhaps you might consider changing it if you are still encountering this.

Final Thoughts:
I have found that even though brass will not entirely fit into a case gage it will fit into your rifles chamber.
If it will chamber and fit into your rifles magazine as well I would call it done and not make any further adjustments.
You may consider annealing your case's neck and shoulder before you perform your full length resize.( your brass may be still too hard)
To that end, you must through trial and error work these issiues out.
Best of luck

Using Norma brass. I feel I'm on the right track now and have a better understanding. I have a few new tools on the way to assist me with making some adjustments. Thanks for the advice.
 
I was shooting last weekend, and I had three cases split when firing that look similar. I was using Federal GMM .308 cases with Sierra 168g TMKs. They were on thier third reload with no signs on examination when initially prepping them. Never any pressure signs using 46g Alliant 2000-MR Pro. Thoughts on why they are splitting? I started to rpelacce them with once-fired winchester cases, but all the necks on them seem to have thickness varying from .013 - .014. inches, so not sure I want to try and turn the necks any thinnner. Thinking I might be better off jsut chucking them all (about 150 cases) and just get some Lapua or Perterson and start over. Suggestions?
 
I wouldn't write off your brass hulls just yet!

I don't understand why you would not want to remove the high spots on your case necks by simply as you know turning them ever so lightly unless you are experiencing neck tension issues.
You do not mention if and how many times your brass cases were annealed or even if you anneal.
If they have not been annealed this may be the culprit.
Brass shell case necks and shoulders work harden with every firing.
With that said, as you already know cases must be annealed at the right temperature and for the correct time.
Templaq , will indicate the correct temp and time under the flame. ( modern electronic annealing machines can literally pay for themselves by allowing your brass hulls an extended life or non annealed brass hulls)
You don't state whether or not you anneal.
If you would perhaps post a few images a better analysis can be made.
Did you look on the inside of your hulls and examine the case walls for any abnormalities.
This can test can be performed with the use of the straight end of a scribe tool.
Just run it along the case necks ID and feel for anything that is out of the ordinary, or you simply use a small flashlight and look at the Nek ID while rotating the case.
If nothing abnormal is found, try a dry neck lube before loading your powder and seating your bullets.
Before we go any further make certain that your die insides are as clean as possible.
( Hornady One-shot die cleaner and case lube works well here)
While we are on the lubricant subject before I FL resize any brass I make it a habit, to gently wipe each brass case neck and shoulder so a to prevent hydraulic dimpling or worse.
once you have FL resized and bumped your shoulder the recommended -.002"examine and wipe clean the case neck and mouth.
Do this with either a caliber specific nylon brush, followed up with a clean Q-Tip. In this manner, you have removed any residuals that your case lube may have trapped in your case neck.
Hope that this will give you something to think about!
 
I wouldn't write off your brass hulls just yet!

I don't understand why you would not want to remove the high spots on your case necks by simply as you know turning them ever so lightly unless you are experiencing neck tension issues.
You do not mention if and how many times your brass cases were annealed or even if you anneal.
If they have not been annealed this may be the culprit.
Brass shell case necks and shoulders work harden with every firing.
With that said, as you already know cases must be annealed at the right temperature and for the correct time.
Templaq , will indicate the correct temp and time under the flame. ( modern electronic annealing machines can literally pay for themselves by allowing your brass hulls an extended life or non annealed brass hulls)
You don't state whether or not you anneal.
If you would perhaps post a few images a better analysis can be made.
Did you look on the inside of your hulls and examine the case walls for any abnormalities.
This can test can be performed with the use of the straight end of a scribe tool.
Just run it along the case necks ID and feel for anything that is out of the ordinary, or you simply use a small flashlight and look at the Nek ID while rotating the case.
If nothing abnormal is found, try a dry neck lube before loading your powder and seating your bullets.
Before we go any further make certain that your die insides are as clean as possible.
( Hornady One-shot die cleaner and case lube works well here)
While we are on the lubricant subject before I FL resize any brass I make it a habit, to gently wipe each brass case neck and shoulder so a to prevent hydraulic dimpling or worse.
once you have FL resized and bumped your shoulder the recommended -.002"examine and wipe clean the case neck and mouth.
Do this with either a caliber specific nylon brush, followed up with a clean Q-Tip. In this manner, you have removed any residuals that your case lube may have trapped in your case neck.
Hope that this will give you something to think about!
Thx. Except for annealing and dry neck lube, I followed all the steps you listed. With Wincheaters brass, my concern is if I turn them, I might have to take some to less than .013 thickness, and that seems a little thin to me. I have not researched a minimum neck thickness. but will as soon as I finish this. The Fedrals were only on their third firing, so it didn't seem annealing at that point would be needed. Trim length per my manual is greater that 2.015, mine were only at 2.010. The Federal necks measured .015. I use a match grade bushing die, and only FL size once-fired brass new to me. I have seen very little brass growth and no donuts. I have some non-annelaed Hornady brass on their fifth firing with no sign of impending issues. I have the capability to anneal cases, but have not felt it needed to date. What is the recommended number of times fired is annealing warranted? I have read articel sayinf everything from after every firing to after every fifth, and everything in between! What do you do? Again, appreciate the time and thougth in your comprehensive reply!
 
Thx. Except for annealing and dry neck lube, I followed all the steps you listed. With Wincheaters brass, my concern is if I turn them, I might have to take some to less than .013 thickness, and that seems a little thin to me. I have not researched a minimum neck thickness. but will as soon as I finish this. The Fedrals were only on their third firing, so it didn't seem annealing at that point would be needed. Trim length per my manual is greater that 2.015, mine were only at 2.010. The Federal necks measured .015. I use a match grade bushing die, and only FL size once-fired brass new to me. I have seen very little brass growth and no donuts. I have some non-annelaed Hornady brass on their fifth firing with no sign of impending issues. I have the capability to anneal cases, but have not felt it needed to date. What is the recommended number of times fired is annealing warranted? I have read articel sayinf everything from after every firing to after every fifth, and everything in between! What do you do? Again, appreciate the time and thougth in your comprehensive reply!
I would suggest you start a different thread to address your exact issue. My thread is older and you're not going to get much action here.
 
I encountered the same problem with my new .300 Winchester Magnum Rifle and cartridge.
I wanted to get to the range early and spend the day in load development, but alas that was not to be.
I used my match die without the busing and FL resized my brass annealed it (these were virgin cases), then on to check COAL. length and fl resize again this time with bushing inserted I also adjusted the die to give me the-.002" shoulder bump.
Now my new brass fit my chamber and my COL gage and was good to go. However, the lot of twenty-five cases that I thought were Fl resized and ready to load well this is what happened.
Imagine my surprise when I could not even insert one case into the COL gage.
This brass was from an older lot and I wanted to use them as well.
My bad I didn't check the cases to make certain that they would fit into the chamber of my rifle.
It was only twenty - five rounds that were loaded and earmarked for load development.
Needless to say, I got out my trusty RCBs bullet puller with the correct caliber collet and broke down all twenty-five rounds I dumped the powder back into the powder hopper.
After getting my brass Fl resized again with the match die set inclusive of the bushing. This time I brought out my Redding .300 Win Mag Body die as well as the #6 competition shell holder set.
Starting with the .010" shell holder and working down to.-006' MY CASES FIT LIKE A GLOVE TO MY RIFLE'S CHAMBER.
IN RETROSPECT I NOW BELIEVE THAT I ONLY USED A NECK SIZE DIE DIE ON THESE OLDER HULLS, HENCE THE PROBLEM.
I THINK THAT A REDDING BODY DIE AND COMPETITION SHELL HOLDER SET(CALIBER SPECIFIC) MAY BE A GOOD CHOICE FOR FUTURE PURCHASES.
With that said please do not rely on just a case gage..
They are made generally to Sammi spec and your chamber's dimensions may have a slight dimensional stacking and still be within tolerances. Remember everything manufactured has tolerance and your rifles chamber is no different.
So if I were you here's what I would do.
If your rifles bolt closes home smoothly and easily without forcing your bolt into battery, well then you are now golden and good to go!
Enjoy your range day !!!
 
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Neck diameter, especially at neck/shoulder junction, on both empty and bullet seated cases !!!
Most likely. I will add also that about every neck I have ever turned was tapered, and thicker on the shoulder end. The neck expands when you seat a bullet, creating the tension needed to hold it in place. Most likely the rounds will chamber fine, if not you will need to turn the necks.
 
308 is a small case for the projectile, my opinion only.
Maybe load em real light.?
Keep your brass, get some 4895 and play with 70% loads...one day
If you load hot then three reloads on the brass is about all you can expect.
Go low node.
Have fun!
Lee
 
it's old and grey wonder if he got it fixed, never used a case gauge, use the horny gauges with about .003 bump and let it rip, more worried about good bullets and powder charges
 
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