I'm getting less than MOA with virgin brass. What would y'all expect to see from the second loading of this brass that was fired from the same rifle? Would you expect accuracy to increase, decrease, or stay the same?
Thanks
Thanks
Virgin brass vs fired brass
- Thread starter N2TRKYS
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Lot of variables, but I would expect the SD to stabilize some since in internal volumes of the once fired brass to be more consistent.
nikeandros
Well-Known Member
i start to reload 2 months ago .. not a lot of experience but I love to learn . so toke a lots of information and I hung out with more experienced reloader. is the consistency of you load that count most.. and alway never lush to the limit.. i was shooting 1 to 3/4 Moa with virgin brass.. i used the same brass ( i think I am at my forth reload already.. i will post pictures they will explain better than me..( 300 win mag Remington 700 long range..)
nikeandros
Well-Known Member
all targets shot at 200 mt.. testing my loads was my third reload.. same federal brass.. hope i was helpful...
Mikecr
Well-Known Member
The first time you fire a case it's forever changed.
So what you get out of new cases doesn't matter, unless you intend only to use new cases.
Beyond that, load performance from number of case firings is not predictable without at least knowing what your cartridge & sizing is (in detail).
So what you get out of new cases doesn't matter, unless you intend only to use new cases.
Beyond that, load performance from number of case firings is not predictable without at least knowing what your cartridge & sizing is (in detail).
benchracer
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Muzzle velocity WILL change if using the same powder charge with virgin vs once-fired brass. Sometimes dramatically so. For that reason, I typically do load development only with brass fired in the rifle the loaded ammo is intended for.
It has been my experience over the past 40 years that trying to do a load work up with virgin cases is a waste of time. Many years ago I almost sold off a rifle that I was only using virgin cases trying to find a load it would shoot. Best load I could find was around 2" @ 100. When I ran out of virgin cases I part sized (bumped the shoulder) some cases using a FL sizer and loaded up the best of the previous loads. Put 5 shots in the same hole and found that that rifle would shoot almost anything you put in it as long as you use a case that had been fire formed with just the shoulder bumped back a little using a FL sizing die.
Mikecr
Well-Known Member
If you were to measure close, new -vs- fully fire formed, and sized as you plan, you would see that all dimensions have changed. This affects capacity directly.
Along with this, the brass grain length has changed(affecting hardness), and clearances have changed. Combined, there will be a difference in the pressure curve rise, given different energy use to fill the chamber with your brass(far more 'contained' at that point). So don't bother load development with all this changing. Take your brass to stable first.
Where a cartridge is small to mid size capacity, with a fastest powder that fills the case, most of a target result/barrel timing was influenced within the pressure peak.
With bigger to overbore cartridges, the pressure peak itself contributes less & less to target results. More slower powder.
Along with this, the brass grain length has changed(affecting hardness), and clearances have changed. Combined, there will be a difference in the pressure curve rise, given different energy use to fill the chamber with your brass(far more 'contained' at that point). So don't bother load development with all this changing. Take your brass to stable first.
Where a cartridge is small to mid size capacity, with a fastest powder that fills the case, most of a target result/barrel timing was influenced within the pressure peak.
With bigger to overbore cartridges, the pressure peak itself contributes less & less to target results. More slower powder.
I do understand all the case change variables but I have a question. I've read many recommendations on this site to purchase at least 200 cases for the life of a gun. How may people shoot all those cases before starting any load workup? For BR world, I can imagine this but for anything less than competition, seems costly. Is new brass and once fired splitting hairs? Cases continue to change even at the 2nd and third firings. Some people even recommend returning brass necks after the 3rd firing due to changes.
For the OP's direct question, if you are MOA with virgin brass, you will be MOA with once fired. You should play with other variables to improve the accuracy.
For the OP's direct question, if you are MOA with virgin brass, you will be MOA with once fired. You should play with other variables to improve the accuracy.
Mikecr
Well-Known Member
IMO, MOA is not a standard of accuracy, but of basic function.
If you desire accuracy, load develop with brass at stable dimension/capacity.
Just 50 cases, with a plan for it, can last the life of a barrel. Especially for a hunting gun. Of course that plan would include cartridge choice and would not have you chasing your tail about fleeting results.
If you desire accuracy, load develop with brass at stable dimension/capacity.
Just 50 cases, with a plan for it, can last the life of a barrel. Especially for a hunting gun. Of course that plan would include cartridge choice and would not have you chasing your tail about fleeting results.
Corey Schwanz
Well-Known Member
If your loading process is solid, you should see similar accuracy results when you get to subsequent firings. I don't put a lot of weight on stuff with new brass since its only new once and then its fired/resized from there on out for its life.
Do a little testing for yourself. Take your load with 5 new cases and 5 that you've fired already and shoot them side by side to see what group differences you see, if any.
Do a little testing for yourself. Take your load with 5 new cases and 5 that you've fired already and shoot them side by side to see what group differences you see, if any.
