So this will be my first time going from new brass to once fired. Just trying to get an idea of what is going to change and around how much I will have to tweak the load that was worked up on the new brass, when loading the once fired. I guess my main confusion is about velocity. A ladder test will show you what velocity and harmonics your barrel is comfortable at, to the best of my knowledge atleast. After the brass is fire formed, I'm assuming case capacity will go up, which then causes me to think velocity will go up as well. Or is it opposite? Is the change in velocity enough to push it out of the node? Obviously some rifles have huge nodes and some have small ones, but on average I guess is what I'm asking. Rifle is a fierce edge 28 nosler shooting 190 lrht in front of n565 in gunwerks brass.
Questions about going from new brass to once fired!
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DoneNOut
Well-Known Member
Might I suggest not over thinking this and go shoot the fire formed brass and report back your findings. Then you will have more answers than questions. I for one look forward to your report.
I had a feeling that reply was coming. Lol was just trying to prepare myself for what was to come! But yes. I will definitely let you know what I find. Thank you!
Savage 12BVSS
Well-Known Member
The biggest difference I've seen is accuracy tends to improve. Doubt the other factors like case capacity and chamber fit will do that much to throw you off. See how it goes.....
ShtrRdy
Well-Known Member
From my experience the once fired brass with the same load will have a little higher velocity. This difference could be enough to throw your "sweet spot" off. Just tweak the powder charge to give you the velocity you had during the first firings and the "sweet spot" will come back.
The reason the velocity is lower on the first firing is because some of the energy developed from the burning powder is used to blow out the brass to fit the chamber.
The reason the velocity is lower on the first firing is because some of the energy developed from the burning powder is used to blow out the brass to fit the chamber.
jimbires
Well-Known Member
I'll use virgin brass to work seating depth tests . then I'll use once fired to work up powder charge . I find that virgin brass usually has a slower velocity .
I like to use new brass for load work-up, and shoot about 10 more, in new cases to check repeatability. Then I will use once fired to see if it repeats the accuracy. If it doesn't, I will load up 50 new brass with that load and set aside for hunting. I will then play around with other bullets, etc with my old brass. I am not a LRH though, nor do I shoot hundreds of rounds a year. I still have rounds left over for long gone rifles that are 25 yrs old! ha.
Too late, you should have measured before and again after; and then the question, measure what?
I have one rifle with with a chamber that is field reject length + .002". When I fire a round in that chamber the case has to fill the chamber from the case head to the shoulder of the chamber before things get serious . It is not something a reloader would think about but it takes time for the case to expand when filling the chamber. After the case has formed to the chamber there is no time lost when using the once fired case unless the reloader decides to start over by full length sizing the case back to minimum length.
F. Guffey
lancetkenyon
Well-Known Member
MOST 28 Noslers I have loaded for (23 and counting now) have shown little case dimension changes between virgin and fired brass. With both Nosler and ADG brass. I have seen no major differences in velocity or accuracy between them.
7RM, .300WM, .264WM, etc. are a totally different animal. I have seen headspace change as much as .023" between virgin and fired brass.
7RM, .300WM, .264WM, etc. are a totally different animal. I have seen headspace change as much as .023" between virgin and fired brass.
I measured every dimension on the case. The only big difference I'm seeing between the new and once fired, is the headspace in the new case is about .005 shorter than the once fired. The body expanded too obviously. But not much
If on one of my rifles the head space changed .023" I would put that rifle away and then start on another one.
F. Guffey
J E Custom
Well-Known Member
That was good advice. The new cases all need to fire form to your chamber before they settle down. and normally the only change is better accuracy. After fire forming size only enough to chamber and you will be surprised how well they shoot.
J E CUSTOM
lancetkenyon
Well-Known Member
Doesn't matter if it was factory or custom, every belted magnum I have loaded for, virgin brass headspace has changed significantly. Between .014-.023". I bump shoulders back .002-.003" when resizing just like any other cartridge after that.
So you were not talking about chamber head space as in the length from the datum to the bolt face, you are talking about something I do not have. My cases do not have head space, my cases have a length from the datum to the bolt face. The difference between the two give me clearance. there was another question about head space, most confusing. I do not have an infatuation with head space. I know about the L Willis digital head space gage and the case head space gage and then there is Hornady-Sinclair renamed comparator.
I Checked SAAMI again, one of the other times I tried to get BART. B. to explain to me where SAAMI says the case has head space; nowhere in their drawings do they claim the case has head space. He called SAAMI and it did not get better. And then there was the tool seller that got better billing through google if he named his tools Head Space this and or that. I did not have a chance because reloaders do not understand how google works.
F. Guffey
After that reloaders had to assume everyone knew what the other was talking about. So I ask.
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