new brass load vs fireformed load

[rockwind1]

my application is precision rifle/long range hunting vs benchrest if that makes any difference.

my question is,

1. if i have the brass from the same lot, yet some is new and some is once fired (fireformed once in my chamber), and i am starting a new load from scratch using the new brass, once it is fireformed it has expanded and if i use the same developed load, won't there be a volume difference inside the fire formed brass and cause a velocity change?

2. if i do use the developed load in the now fireformed brass, does full length sizing/bumping the shoulder the fireformed brass get rid of any accuracy advantages of the fireform?

3. does using fireformed brass really make a measurable difference in my application?

4. is the whole point of fireformed brass mean that you should only neck size it the next time you use it so it stays consistent? it would seem that bumping the shoulder would the greatest effect on volume?


my question stems from an earlier post in which i have 120 fireformed once fired brass and 100 brand new brass. i believe they are from the same lot. i was going to develope a load with the new stuff, fire it, then since it will only have one firing like the other 120, i will combine the groups. (the original 120 was loaded at a place called copper creek so unsure of the load data)

 

[Dusty Stevens]

Dont overthink it. On a hunting rifle youll never know. Oh and FL size everytime- new or old brass. Save yourself some heartache and maybe a hunt and ditch the neck die

 

[done111]

Only bump your shoulder about 0.002" or less for bolt action rifle. There will be a slight difference between new brass and your "standard prepared" fired brass. When I bought 200 pieces of Peterson brass, I worked up a load with the virgin brass. I later reworked the load with the fired brass with very slight changes in powder and found the node was almost the same and then used that amount of powder for reloading from then on.

 

[rockwind1]

hi dusty, can i ask you a follow up question. are you saying that because of field conditions,,, like the concern of have dirt or something in the chamber and a very snug fitting round wouldn't work? or are you saying that because hunting you don't have time for a precision shot? if the later, i am out west and i have had numerous shots where i had all the time in the world to set up for a shot.

i am trying hard not to overthink stuff, which is why i am on here. if i get a better understanding of the "why", that will help me not overthink.


done111: would you say the slight difference in the load make a difference in the precision rifle world,,,or only to the bench shooter?

 

[retired]

in spite of the name there is not much precision in precision rifle( compared to bench rest, but maybe more than hunting)
the reality is that yes at this point you have 2 lots of brass, and a single load may not have the came ballistics.
simple answer is to shoot the new brass at shorter range with the same load you use in the 1x brass.
but then you have 1x and 2x brass.

best answer is to go shoot the new brass so you have one lot of 1x brass and move forward.

 

[Dusty Stevens]

hi dusty, can i ask you a follow up question. are you saying that because of field conditions,,, like the concern of have dirt or something in the chamber and a very snug fitting round wouldn't work? or are you saying that because hunting you don't have time for a precision shot? if the later, i am out west and i have had numerous shots where i had all the time in the world to set up for a shot.

i am trying hard not to overthink stuff, which is why i am on here. if i get a better understanding of the "why", that will help me not overthink.


done111: would you say the slight difference in the load make a difference in the precision rifle world,,,or only to the bench shooter?

you neck size your brass its inevitable that they will become tight. once they become tight enough and its cold outside and youre on the hunt of a lifetime what do you do if a round wont chamber? what if the bolt handle just comes off in your hand when you get those tight rounds? ive seen both situations. it sucks when youre on your only marco polo hunt you get in a lifetime and your rounds wont chamber. the cost of proper dies seems small at that point.

 

[rsbhunter]

I'm probably the least knowledgeable on this subject, but i have read that most guy's are full length sizing there cases.....That being said, it seems to me , if you fireform the new brass and then full length size all the brass then and afterwards, the brass will be identical for each firing....I would look into a Forster fl die with the neck honed to give consistant seating pressure, i would think that might be a solution... And it will make sure there are no chambering or extraction problems..rsbhunter

 

[HTSmith]

For hunting loads I recommend chambering every round from the magazine (with the firing pin removed) ahead of time. Time well spent.

 

[Dusty Stevens]

I'm probably the least knowledgeable on this subject, but i have read that most guy's are full length sizing there cases.....That being said, it seems to me , if you fireform the new brass and then full length size all the brass then and afterwards, the brass will be identical for each firing....I would look into a Forster fl die with the neck honed to give consistant seating pressure, i would think that might be a solution... And it will make sure there are no chambering or extraction problems..rsbhunter

do one even better and buy a FL bushing die where you can actually adjust your tension as the brass lot changes or the brass changes on the next firing. dont get locked down on one neck size or next year it may change.