270 Win Ruger American...Nosler Brass, now shot x4, annealed after x2...110 gr TTSX, 56.0 gr Re-17 (manuals say 52.5-58 gr)...3258 fps...COAL 3.28...FL sized with forster die with neck honed to .004” under OD of neck of loaded round. These are consecutive rounds fired this afternoon....I’ve never seen signs of excessive pressure before, but I’ve probably loaded/shot less than a thousand or so rounds. I’m thinking this load would not normally generate excessive pressure, therefore, I must have done something to compromise my brass- any thoughts/comments appreciated. Thanks.
As real as it gets....
- Thread starter Jody Simcox
- Start date
270 Win Ruger American...Nosler Brass, now shot x4, annealed after x2...110 gr TTSX, 56.0 gr Re-17 (manuals say 52.5-58 gr)...3258 fps...COAL 3.28...FL sized with forster die with neck honed to .004” under OD of neck of loaded round. These are consecutive rounds fired this afternoon....I’ve never seen signs of excessive pressure before, but I’ve probably loaded/shot less than a thousand or so rounds. I’m thinking this load would not normally generate excessive pressure, therefore, I must have done something to compromise my brass- any thoughts/comments appreciated. Thanks.sorry, i'm still learning but how far is too far?
Preacher
Gold $$ Contributor
To far is when it does that to your brass.
Set up the die so your unloaded cases go into the chamber with a very very tiny little bit of pressure needed, without the firing pin assembly in place..
That will cure your separation problem....
BIG CONCERN !!!! I'm curious about how far your brass is hanging out of your chamber . Headspace could be correct BUT with the brass that far out its unsupported . Just going by looks but by the marks on your brass BIG CONCERN , again I'm going from pics and wife is waiting to go . I hope you check , this could be DANGEROUS
I got Nosler 204R brass on their 7th firing with stiff loads and they're still running strong... They've been sized properly though.Welcome to Nosler brass
After full length sizing with honed neck .004” less than OD of loaded round, I then use an expander mandrel .002” less than bullet diameter...gonna have to do a little thinking about my die set up. Have to go back home and look at notes, but I think I set it up per Forster’s instructions. Also, I don’t set shoulders back because my fired cases will easily chamber.
You have got a problem , please have it checked by a smith or at min check case protrusion from barrel , measure bolt face recess add .005 to it and you should be near the case protrusion .
Was this a new gun that has the original barrel?
It's NOT excessive pressure .
You don"t "have a problem" except bad information.
There's nothing wrong with your gun, your dies nor your brass.
This is perfectly normal, the result of following the instructions included with your dies and found in your reloading manuals.
Your choices are;
-throw away your cases after 3 reloads
-learn to set your dies properly
-buy other dies, brand doesn't matter
-learn to take a chamber cast and measure your chamber
-take the time to ask very specific questions and learn WHY it happened instead of asking for kneejerk "answers" and weeding thru folks' guesses. You will have to test stuff yourself.
THE ABSOLUTE ANSWER is that you're over-sizing
Period
THE ABSOLUTE REASON is die settings and quite probably die fit.
It's on you to figure out why, or change your ways.
Casehead separations are like flat tires...... 99% of the time quite innocuous. It's that one percent that gets ya.
Please monitor case length (some call this "COAL" altho that acronym is also commonly used for cartridge overall length) but the thing you need to understand is that you are sizing the shoulders back....... squeezing the cases up thru the die like toothpaste from the tube, and the cases are lengthening. They have to get quite long for them to start crimping in most factory chambers but it _can_ happen..... and this crimping effect will add to your problem by driving presures to damaging levels.
PLEASE.... monitor case growth. Once cumulative growth reaches or exceeds .006 throw the cases away.
Others will argue that cumulative growth of .012 or .015 is still safe but in any case, your goal is to minimize case lengthening or growth.
Case growth is the very first atep in understanding the process and throwing away those cases aftet .006 growth is SAFE, which in my world supercedes all.
Be Safe
Al
Pick up a Hornady headspace comparator so you can see exactly how much you're re-sizing the brass and set your die up correctly.... Setting them up per the instructions will be way oversized and this will happen.... If it was me I would chunk that batch of brass and start over because it's been way over worked and it will happen again... .002 setback is plenty for a bolt gun , a little more for an automatic maybe .003-4.... There's plenty of instructions here on how to set your F/L dies up to keep from over sizing.... Don't feel bad when I first started I did 200 that were found later in a box and they were set back so far I just recycled them , lesson learned....
XTR
F-TR obssessed shooting junkie
What he said.
The sequence of events in your chamber is as follows:
Firing pin hits cartridge and pushes it to the front of the chamber till either the bullet hits hard in the lands (not usually what happens) or the shoulder hits the front of the chamber. (You should rotate the shroud on your bolt one day and look at the firing pin protrusion, it's way out there.)
While the pin holds the case forward the primer ignites the powder.
The pressure expands the case so that it grips the wall of the chamber
Once the case is gripping the wall the base of the case expands back toward the boltface and stretches at the thin part of the web, in your case exctly where you see the ring.
Repeated stretching thins the brass and causes case head separation.
In a 308 it is the same spot, in a 223 it will look to be a little forward of that.
Most of us push the shoulders back .001 to .002, any more than that and you will eventually get case head separations. The more you push it back the faster it happens.
Get a Hornady tool for your calipers. Measure your fired cases and your unfired cases, I'm betting you are in the range of .006 to .010 setback on the shoulders. (or more)
Inspect all of your brass for a visible ring at the spot where that once separated, I'm betting you may find a few. Also, I'd toss any of that brass that is on the same reloading cycle. It's been stretched. There is another version of this where you only get the case head out of the chamber and you have to get the rest of the case out. There is a tool for that. Most people who shoot service rifle have one, gas guns are worse than bolt guns for this.
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Hornady tool https://www.brownells.com/aspx/learn/learndetail.aspx?lid=11470
Sizer die setting for minimum headspace.
If the rifles chamber is on the large side and new brass has to stretch more then normal, brass may be damaged on the first firing. It will show up later as case separations, like your photo.
Sizer die setting for minimum headspace.
If the rifles chamber is on the large side and new brass has to stretch more then normal, brass may be damaged on the first firing. It will show up later as case separations, like your photo.
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A good discussion of your issue as alinwa pointed out:
https://www.tapatalk.com/groups/par...pace-101-for-303-39-s-t3361.html#.WMg3mo-cF9B
https://www.tapatalk.com/groups/par...pace-101-for-303-39-s-t3361.html#.WMg3mo-cF9B
I own and use these same tools (they’re Sinclair, not Hornady so maybe they’re not the same). Got home earlier this afternoon and did some measuring. I had 18 cases (from this same batch) sized and ready to be loaded. Measuring case head to datum. 2 cases measured .005” less than my fires cases, another 2 measured .004” less, and the rest were .001-.003” less. I typically shoot lighter loads (not intentionally, best groups have been there) and my cases have yet to reach recommended trim to lengths...my fired cases chamber without much resistance, so I’ve never tried to set the shoulders back. I’ll do some research this week regarding “proper” die setup...thank you all!
AlNyhus
Silver $$ Contributor
Make sure to remove the primers from your fired cases before measuring.
As far as I know the Sinclair and Hornady are the same tool... Try and keep them .002 and you will be fine.... That brass is probably done..... You can check for case head separation with a bent paper clip etc , that information is also here and I check every case before reloading them....
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