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I have been reloading for many years and I think I know the answer to this question, but thought I would ask anyway. I generally use Lapua brass for my reloading needs, along with Reading Type S Full Length resizing dies. I have a Remington SPS Tactical .308 that I have been reloading for recently. I have been noticing that the bolt handle has been getting harder to lift on some rounds fired at the range. Investigating, I also found that while there is little variation in my overall velocities of shots on my chronograph, there is a correlation to the cartridges which are making the bolt stick and fliers. Using a Stoneypoint/Hornady shoulder gauge I am finding as much as .005-.006 differential in the overall measurement of the brass at the shoulder to the case head. The brass has been used with another .308 in the past and has differential times fired: i.e. one piece may have been reloaded twice and one six times.
My guess as to the why this is happening is brass work hardening. As the number of firings has increased, the ability of the case to spring back and/or hold the dimension in the sizing die is reduced due to the work hardening of the case. The cure should be annealing the brass, correct? At t his point I may also simply retire/recycle the used brass and go to a fresh consistent lot. Let me know your thoughts.
Thanks
Elk
"I won�t be wronged, I won�t be insulted, and I won�t be laid a hand on. I don�t do these things to other people and I expect the same from them." �John Wayne (John Bernard Books, The Shootist)
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Campfire 'Bwana
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Campfire 'Bwana
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If you're going for precision, and given the die you're using I'll assume that's the case, then the brass in a given shooting set should all have the same work history.
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Thank you Mathman. If I was going for absolute precision in a competition load or doing the fine-tuning of a hunting load then you would be 100% correct in your assumptions; however, in this instance I was using more than one lot to filter multiple loads and less worried about the consistency of the brass lot. I believe I even mention that I may simply retire the mixture and not worry about it. When working up a load for hunting, I think using a different lot of the same manufacturer's brass is a reasonable thing to do as a coarse filter when loading in half grain increments - particularly with Lapua brass.
Regardless, the point here is that the same manufacturer's brass going through the same properly adjusted dies is giving me varied results. The full length resizing of fired brass being constant, then the remaining variable is (assumed) work hardening of the brass. I will be annealing the brass when I have time, but was simply asking if anyone else had noticed this and/or had experience with it themselves.
Thanks
Elk
"I won�t be wronged, I won�t be insulted, and I won�t be laid a hand on. I don�t do these things to other people and I expect the same from them." �John Wayne (John Bernard Books, The Shootist)
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Campfire 'Bwana
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I would think your theory correct if you were having issues chambering you handloads, but not extracting them.
If I understand your first post correctly, your loaded rounds chamber fine, but the bolt is stiff, hard to lift to eject the fired round, correct?
This sounds like an over pressure issue and not a work hardened issue.
Can you post the details of your load.
Give a man a fish and he eats for a day. Give a man a welfare check, a forty ounce malt liquor, a crack pipe, an Obama phone, free health insurance. and some Air Jordan's and he votes Democrat for a lifetime.
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Campfire 'Bwana
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Campfire 'Bwana
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Regardless, the point here is that the same manufacturer's brass going through the same properly adjusted dies is giving me varied results. The full length resizing of fired brass being constant, then the remaining variable is (assumed) work hardening of the brass. I will be annealing the brass when I have time, but was simply asking if anyone else had noticed this and/or had experience with it themselves. Getting different sizing results from pieces of brass having different work histories is certainly plausible. Even with matched brass, I've observed sizing/bump differences when the amount of case lube varies piece to piece.
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Campfire Greenhorn
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I have been reloading for many years and I think I know the answer to this question, but thought I would ask anyway. I generally use Lapua brass for my reloading needs, along with Reading Type S Full Length resizing dies. I have a Remington SPS Tactical .308 that I have been reloading for recently. I have been noticing that the bolt handle has been getting harder to lift on some rounds fired at the range. Investigating, I also found that while there is little variation in my overall velocities of shots on my chronograph, there is a correlation to the cartridges which are making the bolt stick and fliers. Using a Stoneypoint/Hornady shoulder gauge I am finding as much as .005-.006 differential in the overall measurement of the brass at the shoulder to the case head. The brass has been used with another .308 in the past and has differential times fired: i.e. one piece may have been reloaded twice and one six times.
My guess as to the why this is happening is brass work hardening. As the number of firings has increased, the ability of the case to spring back and/or hold the dimension in the sizing die is reduced due to the work hardening of the case. The cure should be annealing the brass, correct? At t his point I may also simply retire/recycle the used brass and go to a fresh consistent lot. Let me know your thoughts.
Thanks
Elk I don't know how often you anneal your cases, but certainly after 6 full length reloadings...it ought to need annealing. Secondly, if your ammo is making the bolt stick, if it is before firing...the shoulder needs to be pushed back further. This can be checked with this tool: http://www.lymanproducts.com/lyman/case-prep/rifle-headspace-gauges.phpIf the bolt is sticking after firing...it can only be over pressure. Even if your load recipe has not changed, perhaps your conditions have changed. If you use IMR powder...it is temp sensitive, or perhaps instead of having an empty chamber as you get "ready to fire", your gun is cooling down with a loaded round in the chamber...which is heating the powder up? Maybe let your gun "cool off" while you look at your target with a spotting scope etc, with the bolt open. Just trying to think about all scenarios...
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Campfire Regular
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I agree. Hard to extract is usually a dirty chamber or over pressure.
Aim for the exit hole.
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Campfire Tracker
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I would agree with your quess...work hardning will also effect neck tension...for the same reason, brass spring-back...which can effect bullet strike.
I can usually "feel" the difference in my brass hardness when pulling the expander button back through a sized neck.
I now will anneal after 4 firings.
A simple and easy test for you would be to try it on 3-4 pieces..see if the problem reoccurs.
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Thank you all. Good things to consider. To clarify, the issue shows up when both closing the bolt and extracting the spent casing. In both cases it has been worrisome, hence the reason for performing the comparitive measurements on the brass and my post.
I am consistent with cleaning the bore and chamber. Lube is applied using a lube pad that seems to be consistent relative to cases not sticking nor getting lube pressure dents in the shoulder area from too much lube. After resizing cases are wiped down completely. You've pretty much confirmed what I thought and that I am on the right 'track' with the assumption on annealing. Thank you all again!
Elk
"I won�t be wronged, I won�t be insulted, and I won�t be laid a hand on. I don�t do these things to other people and I expect the same from them." �John Wayne (John Bernard Books, The Shootist)
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