New brass vs once fired

AL PALMER · July 25, 2018, 09:13 AM

Ok,I have new 243 nosler brass.FL resized to my dies,trimed,primer pockets uniformed,flash holes debured.Then I once fire them,clean them,deprime and fl size,then trim and chafer neck.Using the same load as the first firing,what differance could I expect and why?

D Michalak · July 25, 2018, 09:26 AM

Unless this is a trick question, I see no difference.

mikld · July 25, 2018, 09:57 AM

In "theory", the case could be fire formed to the chamber and if the case increases in size, the internal capacity will increase and change pressure (???

). In real life, nope no change...

mgulino · July 25, 2018, 01:28 PM

I don't reload for 243, but I do reload 223, 30-30 and 35 Remington. My experience shows if the reloading process is the same, then you can expect the same results when reloading with either new brass or once-fired brass.
I am just now beginning to experiment with neck-sizing once-fired brass (fired in my gun) instead of full-length sizing. Not enough neck-sized reloads fired yet, but initial results indicate slightly better groups at 100 yds.

RC20 · July 25, 2018, 01:51 PM

Bench rest shooters reload a lot, as they shoot ittty bitty tiny groups me thinks its not a factor.

Guggmeister · July 26, 2018, 10:59 AM

No difference. Until it splits somewhere.

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mete · July 26, 2018, 11:16 AM

The sizing will be for ONE gun. Once you size the THAT chamber you're set .But change guns and you're lost .

Guggmeister · July 26, 2018, 11:29 AM

Quote:

Originally Posted by mete

The sizing will be for ONE gun. Once you size the THAT chamber you're set .But change guns and you're lost .

You are confused.
If he only neck-sizes the used brass then it’s perfect for that gun.
But if he full-sizes then it’s in the spec and should work in any gun but the brass life is shorter (less reloading cycles)

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Jakeway · July 26, 2018, 07:44 PM

I suspect that theoretically, the rounds that started with new brass would be a tiny bit different shape than rounds that start with fired brass formed to your chamber, but loadings 2 through infinity should have no difference. I doubt that the difference between the very first shot and subsequent shots per case would be significantly different. (I mean, if the objective is to find a "pet load", the pet load should be the same for new brass and once-fired brass.) The most efficient and accurate load with new brass is probably the most accurate and efficient loading in used brass. But the group sizes with fire-formed brass should be smaller, or people wouldn't spend the time and effort to do that.

RC20 · July 26, 2018, 07:55 PM

Quote:

No difference. Until it splits somewhere.

If you anneal it won't do that (well done right)

If you full length side but use minimum shoulder bump back it will not split at the base either for 20 or so rounds (maybe more).

It may shoot in another gun fine or maybe not. Depends on its chamber. Shorter or longer.

JeepHammer · July 27, 2018, 12:08 PM

Good time to understand how to do what you want to do.

Once fired, about as close to chamber size as possible.
The less you bend it, the closer it will fit.

Good time for a Datum line case gauge & an accurate caliper or micrometer.
Case in gauge, measure. This is the fired case BEFORE sizing.

Slightly bend case for size, see if it fits in the chamber.
If it does, case gauge & measure again.

Know exactly how much you need to bend the brass, and don't bend it anymore than you have to.

Keep in mind, you are allowing the brass to be 'Larger' than SAAMI/Factory, so you MUST measure and mess with the brass until its bent enough to fit that specific chamber.
It takes a little more fussing around since each brass will have a different rebound ('Spring Back') rate.

About everyone that tracks brass finds effective annealing, if not optimum annealing, helps with longevity.
I find annealed brass takes neck/shoulder sizing better since the brass is both softer & stress relieved to varying extents.

Keep in mind, you can go down a rabbit hole here,
There are TONS and hundreds of dollars of neck sizer dies with fractions of an inch difference, shoulder dies with micrometer adjustments, etc.

It's possible to bump shoulder back a little extra than YOUR specific chamber, and not effect consistency all that much.
This method will make the most stubborn brass fit the chamber, but you won't have brass that's 'Spot On' each and every time, this is simply because the difference in cases, but you do get to use common dies.

If you get a case that's REALLY stubborn and won't measure out, you simply stick a feeler gauge under it to get a little more shoulder movement. This is using a shoulder die and not a full length sizing die.
This saves you buying a set of custom, 'High Tolerance' case holders for the press.

It's up to you how exacting you want to be, how much time you want to put into each case everytime you reload.

mehavey · July 27, 2018, 04:52 PM

Uuuuuuhhh... reading the OP

Quote:

I have new 243 nosler brass.FL resized to my dies,trimed,primer pockets uniformed,flash holes debured.
Then I once fire them,clean them,deprime and fl size,then trim and chafer neck.

The OP:
- FL sized the new brass.....
- FL-sized the fired brass.....

... he is effectively firing the exact same brass.

cw308 · July 27, 2018, 05:16 PM

If you set up your F/ L die to touch the shellholder and sized your new brass that way and duplicated the same process the yes it will be the same . Problem you may be oversizing your brass . Full sizing is the way to go if you ask me but one way to set your full size die is , feed a fired case back into your clean chamber most likely it won't feed then set up your F/ L die , with the ram at the top position with the fired case in the shellholder lower the die down to where you feel it making contact with the case , lower it each time an try it in your rifle untill it Chambers with very little resistance , that's zero case headspace , screw the die down very little until the bolt closes with no resistance , you could be .001 - 2 headspace . Better then oversizing every time .

I don't know if your new to reloading but there are gages to help in finding your chamber length to make accurate full sized cases . By feel using the die will get you in the ballpark .

July 25, 2018, 09:13 AM	#1
AL PALMER Junior Member Join Date: September 5, 2016 Posts: 8	New brass vs once fired Ok,I have new 243 nosler brass.FL resized to my dies,trimed,primer pockets uniformed,flash holes debured.Then I once fire them,clean them,deprime and fl size,then trim and chafer neck.Using the same load as the first firing,what differance could I expect and why?

July 25, 2018, 09:57 AM	#3
mikld Senior Member Join Date: February 7, 2009 Location: Southern Oregon! Posts: 2,891	In "theory", the case could be fire formed to the chamber and if the case increases in size, the internal capacity will increase and change pressure (??? ). In real life, nope no change... __________________ My Anchor is holding fast! I've learned how to stand on my own two knees...

July 25, 2018, 01:51 PM	#5
RC20 Senior Member Join Date: April 10, 2008 Location: Alaska Posts: 7,014	Bench rest shooters reload a lot, as they shoot ittty bitty tiny groups me thinks its not a factor. __________________ Science and Facts are True whether you believe it or not

July 26, 2018, 11:16 AM	#7
mete Senior Member Join Date: June 14, 2004 Location: NY State Posts: 6,575	The sizing will be for ONE gun. Once you size the THAT chamber you're set .But change guns and you're lost . __________________ And Watson , bring your revolver !

July 25, 2018, 09:26 AM	#2
D Michalak Member Join Date: March 11, 2018 Location: Southeast Michigan Posts: 20	Unless this is a trick question, I see no difference.

July 25, 2018, 01:28 PM	#4
mgulino Senior Member Join Date: July 2, 2017 Posts: 198	I don't reload for 243, but I do reload 223, 30-30 and 35 Remington. My experience shows if the reloading process is the same, then you can expect the same results when reloading with either new brass or once-fired brass. I am just now beginning to experiment with neck-sizing once-fired brass (fired in my gun) instead of full-length sizing. Not enough neck-sized reloads fired yet, but initial results indicate slightly better groups at 100 yds.

July 26, 2018, 10:59 AM	#6
Guggmeister Senior Member Join Date: March 10, 2013 Posts: 117	No difference. Until it splits somewhere. Sent from my iPhone using Tapatalk Pro

July 26, 2018, 07:44 PM	#9
Jakeway Member Join Date: October 12, 2017 Location: Near Nashville, TN Posts: 62	I suspect that theoretically, the rounds that started with new brass would be a tiny bit different shape than rounds that start with fired brass formed to your chamber, but loadings 2 through infinity should have no difference. I doubt that the difference between the very first shot and subsequent shots per case would be significantly different. (I mean, if the objective is to find a "pet load", the pet load should be the same for new brass and once-fired brass.) The most efficient and accurate load with new brass is probably the most accurate and efficient loading in used brass. But the group sizes with fire-formed brass should be smaller, or people wouldn't spend the time and effort to do that.

July 27, 2018, 12:08 PM	#11
JeepHammer Junior member Join Date: February 27, 2015 Posts: 1,768	Good time to understand how to do what you want to do. Once fired, about as close to chamber size as possible. The less you bend it, the closer it will fit. Good time for a Datum line case gauge & an accurate caliper or micrometer. Case in gauge, measure. This is the fired case BEFORE sizing. Slightly bend case for size, see if it fits in the chamber. If it does, case gauge & measure again. Know exactly how much you need to bend the brass, and don't bend it anymore than you have to. Keep in mind, you are allowing the brass to be 'Larger' than SAAMI/Factory, so you MUST measure and mess with the brass until its bent enough to fit that specific chamber. It takes a little more fussing around since each brass will have a different rebound ('Spring Back') rate. About everyone that tracks brass finds effective annealing, if not optimum annealing, helps with longevity. I find annealed brass takes neck/shoulder sizing better since the brass is both softer & stress relieved to varying extents. Keep in mind, you can go down a rabbit hole here, There are TONS and hundreds of dollars of neck sizer dies with fractions of an inch difference, shoulder dies with micrometer adjustments, etc. It's possible to bump shoulder back a little extra than YOUR specific chamber, and not effect consistency all that much. This method will make the most stubborn brass fit the chamber, but you won't have brass that's 'Spot On' each and every time, this is simply because the difference in cases, but you do get to use common dies. If you get a case that's REALLY stubborn and won't measure out, you simply stick a feeler gauge under it to get a little more shoulder movement. This is using a shoulder die and not a full length sizing die. This saves you buying a set of custom, 'High Tolerance' case holders for the press. It's up to you how exacting you want to be, how much time you want to put into each case everytime you reload.

July 27, 2018, 05:16 PM	#13
cw308 Senior Member Join Date: September 2, 2010 Location: Plainview , Long Island NY Posts: 3,863	If you set up your F/ L die to touch the shellholder and sized your new brass that way and duplicated the same process the yes it will be the same . Problem you may be oversizing your brass . Full sizing is the way to go if you ask me but one way to set your full size die is , feed a fired case back into your clean chamber most likely it won't feed then set up your F/ L die , with the ram at the top position with the fired case in the shellholder lower the die down to where you feel it making contact with the case , lower it each time an try it in your rifle untill it Chambers with very little resistance , that's zero case headspace , screw the die down very little until the bolt closes with no resistance , you could be .001 - 2 headspace . Better then oversizing every time . I don't know if your new to reloading but there are gages to help in finding your chamber length to make accurate full sized cases . By feel using the die will get you in the ballpark .