300 WIN MAG SPLIT CASES WHEN RELOADING re

[Coltsfanatic1]

Hi all, I am a new member here, and have a reloading issue. I recently bought a T.C Compas in 300 Win Mag. Loaded up 50 rounds of Hornady brass w/ 168 GR Hornady A-Max bullets over IMR 7977 ranging from 75.5 - 80 GR to try to find a decent load for my new rifle.
Range session was great, no issues what so ever. So I decided to load up my fire formed brass. To have a custom round for the rifle. The once fired brass chambers in the action freely, bolt is not tight at all, feels great. (BRASS LOOKS GREAT)
I decided to neck size only, as the brass does not seem to need a bump back. (Note that I have never neck sized before, always have FL sized all of my loads) I only have a lee Pacesetter die set. I set the FL die up by backing it off the fully raised ram about 1 1/2 turns. I fine-tuned the adjustment to make sure the die was not touching the shoulder by smoking the neck and shoulder of one piece of brass and running it through the die until I could see that it was just above the shoulder.
Issue that I am having is that raising and lowering the lubed brass through the die is hard/ very hard, Some easier than others. It seems to be when the neck is being sized. Normal / slightly above normal friction while the neck passes over the expander ball/rod.
The big issue is that about 1/2 of the 20 cases that I have attempted to neck size have split just above the belt. The splits range from 1/4-1/2 way around the case. What is going on??? I am assuming that I have the die set up wrong. But from what I have read and videos that I have seen, this should work.
I have also FL sized a few cases that seem to work ok. Still a lil bit of friction on the up & down but not nearly as bad, and no split cases. Possibly some minor case bulge aboothe belt.
Sorry for the long post but I need some help on this. Feel free to ask any questions, and Thanks in advance.

 

[Matches Malone]

did you clean out the oil they shipped it/stored it in? (that shouldnt cause your issue, but im curious if you took the die apart)
are they splitting when the ram is going down or up?

Solution time. I have had stuck cases...but have never tore brass....even when being new and dumb and thinking i can muscle the stuck case out. I have torn and stredded brass playing with dies and using cases that dont belong in,

Are you sure the dies and the shell holder are for a .300 win mag....?

 

[Coltsfanatic1]

Yes, the dies were cleaned when I first opened and used them to load my first batch of rounds (50). I also took them apart and cleaned them again. thinking there was excessive lube or something inside causing the current issue.

Yes they are 300 Win Mag dies.

I believe the brass is splitting by a combo of crushing on the way up and splitting on the way down. I'm not sure that's a guess. There are no signs of bent, dented, or crushing. Just a crack in the brass.

On the once fired brass there seems to be a distinct line (that you can feel with you finger nail) just above the belt. Similar to the case separation bright line. It's not a crack, it's a very slight bump. I'm assuming this is case bulge that I have read about in relation to belted cases. This is where they are splitting.

What I don't understand is how this could happen if the brass has only been fired once. I'm stumped,

 

[Ayoung1]

I'm assuming you aren't annealing these before neck sizing. If you have the means to do so I'd anneal a few and see what happens after sizing.

 

[Matches Malone]

unlikely it would be annealing anyways, its at the case head where the biggest problem is...

OP i think you solved your own problem. I cant see what you see, but from what you described if you think its a bulge or something wrong with the case above the belt then it probably is.
That particular load might have been over pressured in YOUR rifle...that can be any number of reasons. So i would start investigating that, maybe try a factory ammo, try 3 rounds inspecting each, then load them up in the die and see if they work well, that would be a fast way to rule the die out. Could be a bad lot of brass, the rifle (chamber tolerance etc), the load, but yeah case bulge around the belt isn't normal. did you FL resize before you loaded up the first batch of 50?
Hornady brass is known to be a softer brass...do with that as you will. Post your finding, curious myself.

 

[Milo 2.5]

I'm assuming you aren't annealing these before neck sizing. If you have the means to do so I'd anneal a few and see what happens after sizing.

Why or how would annealing solve any of this?

 

[supercorndogs]

If it was over pressure rounds they would not have fit easily back into the chamber. Also a belt bulge of a few thousandths will stop them from chambering.

I doubt you are splitting them with the sizing process. How many firings? If you just fired the factory cases, once, then neck sized them and they were already split. I would suspect your new 300wm has long chamber. A go/no go will not measure anything for you here because it just measures the belt, where the round is supposed to headspace. I would get out my comparator and measure a fired and an unfired piece of brass. Could be one firing is almost making them case head separate, because the shoulder in the chamber is so far forward.

As for rough entry into the die. Could be several things. I have had rough dies that needed polished. It could be the brass is huge, form a giant chamber. Make sure you get plenty of lube in neck and expander ball shouldn't give much trouble.

 

[Milo 2.5]

Yes, the dies were cleaned when I first opened and used them to load my first batch of rounds (50). I also took them apart and cleaned them again. thinking there was excessive lube or something inside causing the current issue.

Yes they are 300 Win Mag dies.

I believe the brass is splitting by a combo of crushing on the way up and splitting on the way down. I'm not sure that's a guess. There are no signs of bent, dented, or crushing. Just a crack in the brass.

On the once fired brass there seems to be a distinct line (that you can feel with you finger nail) just above the belt. Similar to the case separation bright line. It's not a crack, it's a very slight bump. I'm assuming this is case bulge that I have read about in relation to belted cases. This is where they are splitting.

What I don't understand is how this could happen if the brass has only been fired once. I'm stumped,

I would seriously have a qualified person inspect your chamber.

 

[918v]

How much does shoulder length grow between new and 1x fired?

 

[Coltsfanatic1]

. It seems that the cases are spliting due to the force being put on them when inserting and pulling them out of the die. Most of the pressure seems to be when the neck is coming out of the die. There is a decent amount of pressure needed to insert the neck into the die as well. The resistance going over the expander seems to be avereage / above average for bottle neck cases. I also reload 30-30, & 25-35 which are also bottle enck cases, However this is the first time that I have ever attempted to do a neck size only.

From my neck size die set up discription above, can anyone tell me if this is correct? Is it posssible that the brass is that week after only a single firing. As noted in my original post above these were test loads ranging from just above starting GR to just below max GR. .A bit more information & answers to questions: Thanks for all of the replies.

Did the cases split above the belt by just sizing or after firing a sizedcase ?Cases were new, FL sized and fired onces. Cracks appeared upon attempting to neck size fire formed brass.

Start out by polishing theexpader. The dies worked flawlesly when full length sizing the brass on the prior use. Unless something happend to the expander I do notthink that is the issue. Possibly a set up issue.

what type of sizing lube are youusing ? I am using Lee resizing lube.

How old was the brass? Brass was brand new purchased from Bass Pro Shop 1-week prior to loading. This was the first time the brass was fired.

How much is your brass moving from new to once fired?The new brass was trimmed to 2.620, the once fired brass now measures between 2.621 -2.623

How do you lube the cases before sizing? I use a small amount, rubbing it so it leavs a light film over the body & neck. Try not to get any on the shoulder.

Pictures attached show one cracked case, and a once fired case before attempting to neck size. About 1/2 of the cases end up spliting.
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[spife7980]

Your pics dont work

I am using Lee resizing lube.

Ive heard that the lee lube isnt very good, might be worth it to try some imperial or one shot or just make your own but I doubt that is the cause of your issue. Very likely why they could be so tough to move in and out though.
​​

The dies worked flawlesly when full length sizing the brass on the prior use. Unless something happend to the expander I do notthink that is the issue. Possibly a set up issue.
Brass was brand new purchased from Bass Pro Shop 1-week prior to loading. This was the first time the brass was fired.

That there is some conflicting info and Im having a hard time making heads or tails of what you are doing.

You say that the dies worked flawlessly when sizing the brass on the prior use. Thats impossible if you are using new brass.

Or do you mean that you have other win mags that you have used the dies on before?

Or did you take the new brass and full length size those before the first loading? If you did that you could have set the already short shoulders back even further creating even more headspace that then it had to fill on firing and that would likely be the cause of your separation. You chopped the knees out from under it before they ever got a chance to run.

The new brass was trimmed to 2.620, the once fired brass now measures between 2.621 -2.623

We dont care about your over all lengths, thats only helpful if you need to trim. What we are wondering is how far your case shoulders moved forward from new to fired. And from new to new after you full length sized them before loading if you did that.

From my neck size die set up discription above, can anyone tell me if this is correct?

Just set them up to full length size since they are full length dies, quit trying to make them into something they arent and expecting to be trouble free. That could also be a point of issue but without having proper measurements we cant tell whats going on.

 

[Coltsfanatic1]

You say that the dies worked flawlessly when sizing the brass on the prior use. Thats impossible if you are using new brass. Yes new bras and the dieaas work flawlesly (meaning as theypically work when full sizing new bass) No issues what so ever.

Or did you take the new brass and full length size those before the first loading? If you did that you could have set the already short shoulders back even further creating even more headspace that then it had to fill on firing and that would likely be the cause of your separation. You chopped the knees out from under it before they ever got a chance to run. Exactly what I did, FL size the new brass. to my understanding, you should always FL size new brass. This is what I have read and done numerous times when using new brass. If this is not hte case please advise However you note regarding bumping the shoulder back even further does makes sense. This is what I do not understand Lee's direction for setting the FL sizing die is as follows "Screw the full length sizer in until it touches the shell holder. Then lower the ram and screw the die in 1/4 to 1/3 turn more" Wouldn't this set the shoulder to the proper position and not further back than it would need to be?

What we are wondering is how far your case shoulders moved forward from new to fired. And from new to new after you full length sized them before loading if you did that. Yes, FL sized them, But I did not measure them as I thought by FL sizing new brass, that you are bringing them to proper spec.I will need to get the caliper attachment tool that measures off of the shoulder. Can this also be done by measuring from the point of where the neck meets the shoulder?

Just set them up to full length size since they are full length dies, quit trying to make them into something they arent and expecting to be trouble free. That could also be a point of issue but without having proper measurements we cant tell whats going on. I think this is the best advise, and most likely the issue @ hand.. I am going to pick up a cutlet neck sizer and use that.

I have attached the pictures for reference. take a look @ the once fired picture with out the crack and let me know if this is what a once fired belted mag should look like. This is my first belted mag cartridge and the first time that I took it out shooting, so I have nothing to reference it to. You will be able to see a slight bulge just above the belt. It goes all of the way around the case. However due to camera angle you can only see it on the left side of the picture. All of the fired cases fall freely in & out of the chamber. Thanks for all of your help.

 

[spife7980]

Again, I cant look at pics because they dont work. This is all I can see.




Many case shoulders saami specs have a range of head space, say "1.890-.020" which means anywhere from 1.870-1.890 would be in spec. New cases will tend to be on the low end so that they will be a universal fit but that also means they have a lot of space they have to fill when firing and bumping them further back just exacerbates the issue.
As an example taking a case thats 1.872 would be just about bare minimum from the above numbers. Screwing your die in until it touches the shell holder could set that case back to say 1.855. That would then leave your shoulders .015 below the minimum spec of 1.870. If your chamber is max spec that could mean your brass is having to expand .035" (1.890-1.855). So you can see how that would lead to drastically short life.
A belted magnum throws an extra wrench into the equation as it headspaces off of the belt and not the case head, so theres actually two directions of case growth, both forward of the belt where the brass fills the chamber and behind the belt where the case head fills the bolt. The best way to get numbers off of these is to set your dies up for brass thats once fired so that both of those expansions are taken into account, factory brass has zero taken into account.

For measuring the shoulders you should get a kit like this, you dont have to get the entire group, just the red body and appropriate silver bushing is all thats necessary but if you reload for more than 1 or 2 things it can be worth while in the end to. 300 WM is bushing E- .420".
https://www.hornady.com/reloading/pr...il-base-kit#!/

https://www.midwayusa.com/product/10...ith-comparator [IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/www.brownells.com\/userdocs\/skus\/p_749005148_2.jpg"}[/IMG2]





By using these you can actually measure your cases and avoid setting them back to far. Most die instructions are generic BS, lee included; theyll work in everything but as you are discovering they are also way overworking everything. I would load up a couple actually virgin new cases, fire them and then set your dies up so that you only bump the case shoulders back .002". Then because you have them set up for the actual resultant case conditions you could run the rest of the new in without shortening the case life to 1 shot. Bumping back more than .002 will lead to shorter case live but only bumping them back .002 isnt drastic enough to really have a tangible effect on the case life. Ive had both neck sized only and full length sized cases go over 15 firings apiece.




In line with the headspace bushings you should also get a bullet comparator. This will allow you to measure the bullet depths by the ogive (curve of the bullet where it meets the lands) which is more accurate than over all length. My bullets are all seated within .001" of an inch on ogive but on some bullets the over all lengths can vary in range as much as .008" You can see how .008" of play can make setting up dies accurately difficult. You dont need them all or another body, these bullet comparator bushings will fit in the red anvil that comes with the headspace bushing kit. The bullet comparators are by caliber so you would just need the .30 for your 300 WM.

https://www.hornady.com/reloading/pr...let-comparator

https://www.midwayusa.com/product/10...with-6-inserts [IMG2=JSON]{"data-align":"none","data-size":"full","height":"406","width":"406","src":"http:\/\/www.cdsgltd.co.uk\/media\/catalog\/product\/cache\/1\/image\/9df78eab33525d08d6e5fb8d27136e95\/c\/d\/cd1103026-1_1_2.jpg"}[/IMG2]



Ive heard great things about the collet dies, you should enjoy much more success with it then trying to use a full-length-but-neck-only set up albatross. It would be much more appropriate to use on new new brass to even out the neck tension. Any further sizing would just be working backwards again since they already fit in the chamber.

 

[supercorndogs]

They are not cracking from going in and coming out of the die hard. The rim would pull off the case way before you would pull one in half.

Sizing your brass with a hard over center on the shell holder puts your brass at the smallest amount that die can. There is the first problem. By maximizing the amount the shoulder grows on the first firing, you are minimizing your brass life. You get so many thousandths of shoulder bump before your case head begins to separate.{or so many thousandths of stretch}

You need to get a compactor, measure some new brass, and some fired brass. Either your FL die is short, or your chamber is long. All the brass you have prepped for this gun this way, needs to go straight to the trash. If your chamber is long, there are ways to blow out your shoulder to fit your chamber, without stretching the case so much at the head. But you need to start with new brass. Your brass has been stretched to point it is un safe to use.

 

[Coltsfanatic1]

Thank you very much Spife. I think you are 100% correct in that I pushed the shoulder back to far causing exsesive stretching of the brass. I will set up the dies basd on my fire formed brass dimensions, and see if that takes care of the problem. It looks like the once fired brass that I have now may need to go straight into the trash for the sake of safety. I'm glad that I only loaded up 50 rounds and not the other bag of brass that I have. Thanks,

Thanks to all that posted, Its greatly appreaciated, if anyone has anymore advise or thoughts on the matter dont hesitate to reply..

 

[spife7980]

You can fold open and stick a paper clip in and see if you can feel a divot or step in the brass shoulder, it would be exactly where the others are separating at. Each firing that section of the case will get blown forward and each sizing it is squeezed and pushed down and it creates something sort of like a crease. And like a crease each time it gets weaker and weaker until it cracks. Behind the crack it will get narrower where the body is stretching forward and the a lip that is the thicker material. On a properly sized case you can begin to see this appear externally after many sizings as ring with a different sheen. In your case it appears you moved so much material back and forward that it has skipped the slow progression and gone straight to failure. Try the paper clip and see if you can feel it. If not take a dremel or snips and ohysically open up the case and see if you can visually see anything. If you're going to trash it you might as well see what's going on and get some first hand experience with the details and a little hands on experience with good test subjects.

[IMG2=JSON]{"alt":"Image result for case head separation","data-align":"none","data-size":"full","src":"http:\/\/accurateshooter.net\/Blog\/casehead03.jpg"}[/IMG2]

 

[918v]

You don't need a comparator, just a 9mm or 40 case to measure the shoulder length. If the growth is excessive, your case walls will thin out like in the pics. In my chamber the shoulders grow .022" from new to 1x fired and then I only bump .002" to get another 12-15 reloads out of them. I size using a Redding body die and a Lee collet neck die. My sizing effort is low.

 

[Milo 2.5]

You need to get a compactor, ???

He apparently has a compactor, his die, lol

 

[lash]

Hey! Don't make fun of him! My auto correct says that I'm using a capacitor to measure my relative headspace.

Not that it not possible, just not practical.

 

[Milo 2.5]

Hey! Don't make fun of him! My auto correct says that I'm using a capacitor to measure my relative headspace.

Not that it not possible, just not practical.

It friggin fit, lol

 

[supercorndogs]

Hey! Don't make fun of him! My auto correct says that I'm using a capacitor to measure my relative headspace.

Not that it not possible, just not practical.

Comparator. I don't even know what letters I typed, LOL. I didn't spell it right again, but it auto corrected to the right word. Compactor was the problem, comparator the solution, be it bought or scrounged.

 

[Deleted member 10043]

First, don't back off 1 1/2 turns thinking you are only neck sizing. Go back and look at the instructions. At the very least the Pacesetter die should just touch the raised ram for partial FL sizing. Second, take the die apart and inspect the parts.

 

[Coltsfanatic1]

"UPDATE"

I took the FL die apart and cleand with 0000 steel wool. Ran the remain 30 cases through a ultra sonic cleaner. Reset up the FL die as previously set up to partially size the body and neck without bumping the shoulder.

All remaining 30 cases sized perfect and smooth. Minimal up & down pressure, with no signs of case separation as I was previously experiencing. So im thinking that the issue was due to either dirty brass or a dirty die. Probably both were contributors to the issue. I originally lost 10 cases out of the first 20 that were sized, and 0 out of the next 30.

As far as case growth, I did not measure my original Hornady brass from the shoulder, so I can not compare how much it grew. However, I just loaded up some Winchester brass that most cases measured 2.020 (shoulder) and grew to 2.035 (shoulder) after fired (same that the Hornady brass measures after fired) For a total growth of .015, Not sure if this would be deemed excessive or not.

Thanks to all that posted your thoughts, experiences, and advise. I did learn a few things from this experience. That's the thing about reloading, Always room for growth!! Feel free to reply with any more questions or comments. Thanks,

 

[Yondering]

As far as case growth, I did not measure my original Hornady brass from the shoulder, so I can not compare how much it grew. However, I just loaded up some Winchester brass that most cases measured 2.020 (shoulder) and grew to 2.035 (shoulder) after fired (same that the Hornady brass measures after fired) For a total growth of .015, Not sure if this would be deemed excessive or not.

Yes, that is excessive. Set your sizing die to bump the shoulders back no more than .003"-.004", so that sized brass measures 2.031-2.032" by that same measurement. Bumping back even less is acceptable, depending on your application.

 

[Yondering]

You can fold open and stick a paper clip in and see if you can feel a divot or step in the brass shoulder,

Or just shine a light down into the case and look for the shadow. It's plainly visible. It may only be on one side.

 

[Milo 2.5]

"UPDATE"

I took the FL die apart and cleand with 0000 steel wool. Ran the remain 30 cases through a ultra sonic cleaner. Reset up the FL die as previously set up to partially size the body and neck without bumping the shoulder.

All remaining 30 cases sized perfect and smooth. Minimal up & down pressure, with no signs of case separation as I was previously experiencing. So im thinking that the issue was due to either dirty brass or a dirty die. Probably both were contributors to the issue. I originally lost 10 cases out of the first 20 that were sized, and 0 out of the next 30.

As far as case growth, I did not measure my original Hornady brass from the shoulder, so I can not compare how much it grew. However, I just loaded up some Winchester brass that most cases measured 2.020 (shoulder) and grew to 2.035 (shoulder) after fired (same that the Hornady brass measures after fired) For a total growth of .015, Not sure if this would be deemed excessive or not.

This win brass, was it new or had it been fired and sized, because if it was new, you have issues. Realize, it only takes once letting a case grow like that to compromise it, casehead sep is inevitable.

 

[918v]

Wrong.

Belted mag brass typically grows like that, .015-.025"

 

[supercorndogs]

"UPDATE"

I took the FL die apart and cleand with 0000 steel wool. Ran the remain 30 cases through a ultra sonic cleaner. Reset up the FL die as previously set up to partially size the body and neck without bumping the shoulder.

All remaining 30 cases sized perfect and smooth. Minimal up & down pressure, with no signs of case separation as I was previously experiencing. So im thinking that the issue was due to either dirty brass or a dirty die. Probably both were contributors to the issue. I originally lost 10 cases out of the first 20 that were sized, and 0 out of the next 30.

As far as case growth, I did not measure my original Hornady brass from the shoulder, so I can not compare how much it grew. However, I just loaded up some Winchester brass that most cases measured 2.020 (shoulder) and grew to 2.035 (shoulder) after fired (same that the Hornady brass measures after fired) For a total growth of .015, Not sure if this would be deemed excessive or not.

Thanks to all that posted your thoughts, experiences, and advise. I did learn a few things from this experience. That's the thing about reloading, Always room for growth!! Feel free to reply with any more questions or comments. Thanks,

You might take one of your junk cases, do a hard over center size on the shell holder, and extrapolate how much the shoulder was moving forward on the first firing before.

 

[Milo 2.5]

Wrong.

Belted mag brass typically grows like that, .015-.025"

I should have stayed out of this one not being a belted mag guy, my only experience an stw, but do know my tolerances way tighter that .015-.025", more like .008" and it stumped me at the time.

 

[spife7980]

Agreed, .015 is fine for a first firing and there isnt much you can do about it short of rechambering.

Is it more than you would like. Yes.
Is it something you dont have a choice on and have to live with? Yes.
Will it prevent these cases from working in the future? No.

Just size them down .002 to 2.033 from now on and you should be just fine. Just keep an eye on your brass as you should be anyways.

 

[Deleted member 10043]

There is no way to get a Lee Pacesetter set to not bump the shoulder AND not cause the shoulder to grow unless you spend a lot of time at it and get lucky. And the setting will change after the next firing and subsequent resize. If you want to neck size then just use Lee's neck sizing die.

 

[918v]

I should have stayed out of this one not being a belted mag guy, my only experience an stw, but do know my tolerances way tighter that .015-.025", more like .008" and it stumped me at the time.

I have a TRG42 that grows shoulders .020" and have brass I dug out of the dirt that show .015-.025". Auto-loaders are the worst.

People need to understand that belted mag chamber headspace is measured off the belt, not the shoulder. But to prolong case life we need to headspace our reloads off the shoulder, I bump .002".

 

[Sendit6.5]

I use a Larry Willis collet die for sizing my 300wm brass. Like 918v, I bump .002" because it's predominantly a hunting rifle. Then I use a Redding Type S bushing neck die to set neck tension. I've yet to have trouble near the belt since I started using the Larry Willis sizer. Primer pockets get loose before I get thinning above the belt.


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