Let me start by saying I only been reloading for a couple of years. I have worked up a load for my TC Encore in 300WM. I full length size and its 76.5 grains of R19 under a 150 grain Nosler BT. It shoots very well from my rifle. I have cycled my brass though 3 reloads with no issues. On my 4th time through the brass I decided to try Varget. I made several loads from 55 grains up to see if was something I wanted to peruse. I shot 3 round groups all the way up to 58.5 grains with no issue. I replaced my targets and went to do it again. On this pass I experienced several case failures where the case would separate from the head about 1/4in above the belt. They were all over the charge range IE I would shoot the minimum charge no prob, got up .2 grains and one out of the 3 would fail. Go up .2 grains from that all would fire fine. Go up .2 more grains and have a failure ect. None of the cases showed any stress and were all sized the same amount. I don't know what to think. Is it the cases going beyond its service limits or is it where I changed to Varget powder. Any input would GREATLY appreciated. Thanks in advance -Bill
- Thread starter Dominant Predator
- Start date
Do they look like these?
Magnum cases get stressed and if you over size them, you'll get stretching and case head separation.
Just a fact of life.
Those 7RM have five, perhaps six cycles on them.
Chris
I don't have personal experience with the 300 win mag but as a reloader I'd question if your over working ur brass if ur sizing to minimum or bumpin the shoulder to much which in turn makes it stretch and shortens life quicker. Also if 4s been the breaking point start using the paper clip method to save ur self the hot gas to the face.
Chris: That is exactly where they are breaking but they do not look like that. Except the one that is the furthest to the right with the 2A marks on it. All my cases look like that one.
Gixxer: I am unsure if 4 is the point. That batch was the most I have ever used the same piece of brass. Please excuse my ignorance but what is bumping the neck? I have seen the phrase before but do not completely understand it. I got into this kind of half assed, loading for my pistol and my cheapo 270. I have only really tried to get a good recipe and really focus on the finer tuning lately. Where can I find info on the paper clip method? I'm sure I can search but if you have any recommendations I would appreciate it. Thanks -Bill
Gixxer: I am unsure if 4 is the point. That batch was the most I have ever used the same piece of brass. Please excuse my ignorance but what is bumping the neck? I have seen the phrase before but do not completely understand it. I got into this kind of half assed, loading for my pistol and my cheapo 270. I have only really tried to get a good recipe and really focus on the finer tuning lately. Where can I find info on the paper clip method? I'm sure I can search but if you have any recommendations I would appreciate it. Thanks -Bill
You take a paper clip, or piece of wire and bend a 90* hook onto the end that is small enough to allow you to place it into the case. You'll then run it down the inside of the case body. If your cases are about to separate, you'll be able 'sometimes' to feel the crack. You can also shine a light down into the case and see what you see. Do this after cleaning.
If you're going to be reloading more bottleneck cartridges, invest in the Stoney Point/Hornady headspace gage set.
This will allow you to precisely measure a fired case and then set up your sizing die to precisely bump the shoulders back .002"-.003".
You can google Hornady headspace gage.
Chris
You do need to understand what is bumping the shoulder in resizing your cases. Here's a couple of links that should help.
http://www.youtube.com/watch?v=KCLtpCPe-MU
http://www.snipershide.com/shooting/showthread.php?t=43879
You need to measure the the fired cases from your rifle and then adjust your F/L die to bump your case shoulders back (minus) .001"-.002". You are likely bumping/resizing too much and stressing/stretching your brass too much. I did that many years ago in a .338 Win. Mag. and only got 3 firings out of them before they case head separated. Many new reloaders don't understand the need for this and lose too many cases. Your Varget tests have nothing to do with this. It's your resizing.
http://www.youtube.com/watch?v=KCLtpCPe-MU
http://www.snipershide.com/shooting/showthread.php?t=43879
You need to measure the the fired cases from your rifle and then adjust your F/L die to bump your case shoulders back (minus) .001"-.002". You are likely bumping/resizing too much and stressing/stretching your brass too much. I did that many years ago in a .338 Win. Mag. and only got 3 firings out of them before they case head separated. Many new reloaders don't understand the need for this and lose too many cases. Your Varget tests have nothing to do with this. It's your resizing.
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The responses above are the solution to your problem, especially the gages that allow you to precisely measure how much the shoulder has been moved. You put the gage on a caliper, and the tool indexes on the shoulder so that you will measure from the case head to a point on the shoulder. Take a fired case, measure it, and then set up your die so that when you resize the shoulder is only moved back .001 to .002 for a bolt gun. As long as the brass chambers smoothly it has been resized enough, you are looking for a minimum of sizing to accomplish that. What happened was that when you resized the case you resized it too much, and the shoulder was too far away from the front of the chamber. Naturally on firing, the brass experiences over 60,000 psi and quickly stretches until it contacts the chamber walls. When the brass has been sized too small like yours, a lot of brass will flow forward. Then you sized them again and started the whole thing again. Eventually the brass gets thin right where you described, which you can sometimes see as a bright ring around the case, or feel with the paperclip tool as a "dip" in the inner case wall.
By the way Varget is too fast of a powder for the 300WM. Safe charges wont fill the case much, you need to find a slower powder. Lots of info in the load data section here. Also, buy a couple reload manuals, I like the Lyman and Sierra ones, read through those, and then check out the stickys here in the reloading forum. No need to reinvent the wheel and experimenting in reloading without the experience to know what you are doing can lead you where you don't want to go.
By the way Varget is too fast of a powder for the 300WM. Safe charges wont fill the case much, you need to find a slower powder. Lots of info in the load data section here. Also, buy a couple reload manuals, I like the Lyman and Sierra ones, read through those, and then check out the stickys here in the reloading forum. No need to reinvent the wheel and experimenting in reloading without the experience to know what you are doing can lead you where you don't want to go.
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Thank you all. I have 2 other questions. All of the information I have found here and else where on this matter is regarding bolt actions or semis. With a noticeable difference between those 2 I have to ask what if anything needs to be done differently with single shots rifles like the encore? Also was I misinformed when I was told that on the 300WM in an Encore the head space was based off the belt and not the shoulder of the case? Thanks a thousand times over for the help. All of you have been very helpful. Being that I am new to the group it goes a long way to be met with such helpfulness not to mention that I'm not being degraded for no knowing something and trying to learn it. I have a personal goal of shooting confidently at 500yrds by this fall and I know there is A LOT to learn to get there.
What I have found, and learned here and elsewhere, is that depending on the way the chamber is cut it may indeed headspace on the belt on the first firing. After that, the case has expanded to fit your chamber and when you will resize the shoulder .001 to .002 the case is now headspacing on the shoulder. You can ignore the belt.
Awesome. Can't wait to hit the press this weekend and see what I can get done.Thanks agian.
I think these guys have you on the right track. Only thing I might suggest is to get one of Larry Willis' Innovative Technologies dies that sizes that area at the shoulder your sizing die can't.
Ok, Ive just tried that paper clip test. I can not feel a line per say. When I get down to the very bottom of the case wall it feels rough in texture but dose not make the paper clip "hang" on a score like I thought it would. Is what I'm feeling there cause to no longer use the case?
Don't resize any more than necessary. Have you tried neck-sizing, then seeing if they will chamber? If not, as previously suggested only bump the shoulder .001-.002.
FWIW in a bolt gun, I have neck-sized 300WM and gotten 7X reloads without the need for FL sizing or any bad cases out of 200. On the 8th reload I started to need to pick a few for thinning in the suspect area.
FWIW in a bolt gun, I have neck-sized 300WM and gotten 7X reloads without the need for FL sizing or any bad cases out of 200. On the 8th reload I started to need to pick a few for thinning in the suspect area.
No I have not necked sized. I have a neck sizer for my 308 but I am under the impression it will not work on the 300. I plan to get one asap.
Since belted magnum cases headspace off the belt, the shoulder dimensions aren't as tightly controlled as those which use the shoulder datum for headspace. As a result many magnum chambers are pretty generously cut. If you setup the FL die per the directions then you are sizing down to minimum dimension which will result in head separation due to case stretch. Best thing is to get a headspace comparator (Hornady, Sinclair, RCBS, etc) measure one fired unsized cases to get your baseline and adjust the FL die to size the case no more than you have to.
I forget what site I was pulling from, possibly Noslers but not 100% sure but I thought it was a bit low myself. I don't use all that much less then that for my .308.
