New Brass load development or fireform first

[CharlieNC]

Shooting 223 in fclass, which involves quite a bit of brass, I develop a load using new brass and shoot it all. Then I evaluate fine tuning the fire formed brass but never found a difference. I develop and tune based on finding a stable poi so I would not expect a small change in case capacity to cause a significant difference. And new brass fits my chamber well.

 

[dusterdave173]

I appreciate all of the input--I am just working to learn--I have found that after 4 or so loadings something was changing--necks were acting different--so I ordered an annealer and will sort of start from scratch after a couple years of learning_ I am going to start fresh--use all I have observed and learned--start slinging some Bergers down fresh barrels and just see.
Thanks for everyones input They just built a 600 yd range 11 miles from me so I am rubbing my hands together and smiling

 

[mikecr]

There is a reason that many folks observe great results with new brass, and it validates that new brass is different than fire formed. But unless you intend to shoot only new brass, there is no reason to care about that. And there is no reason to chase your tail either.

If you're going to be counting on formed brass, then waste no efforts getting it there. Make it your plan.
-You don't need 500 stable cases at a time.
-Load development should go faster/better while brass is no longer changing with each cycle, and your barrel has settled. So it will take fewer development shots, which counters the fire forming numbers.
-While fire forming, you can do pressure testing, primer testing, seating testing, and work out system bugs before engaging in powder development.
-You can choose a cartridge, chamber, custom dies that greatly reduce brass changing in general.
-You could buy & have barrels finished in pairs, so that the 2nd barrel can be used for more of it's accurate barrel life.

Some folks hold a notion that Ackley improving adds to fire forming,, reducing barrel life.
But they haven't thought it through.
ALL brass needs to be fire formed just the same (whether a little, or a lot), and AI increases brass life, reducing the changing of brass, and therefore reducing the fire forming of new brass within the life of barrels.
Ackley improving reduces change.
And directly fire forming to stable reduces the chasing of that.

 

[Fclassfool]

I shoot a .266nk Dasher I've won matches with Alpha neck turned only and shot 200x targets while fireforming Lapua BR brass to Dasher ymmv

 

[Herzo]

Perhaps I am missing something, but I don't see that fire forming applies if we are discussing standard cartridges in standard chambers. While the cartridge will expand to conform to the chamber, there should be minimal volume difference between a new cartridge as it is firing and any subsequent loading. The reason to deal with a fired case is to establish the volume of that case in your rifle and perhaps adjust your load accordingly. Subsequent full length sizing should return the case volume to something approximating the new case volume. Yes the temper of the brass will change during subsequent firings, but that is an ongoing process and not pertinent to this discussion.

In the case of a "wildcat" or an AI, fireforming is certainly of value.

 

[tmwinds]

I am trying to make this 223 shoot in 300 yard benchrest competition. If I can't do it I am going to swapping out barrel's to 6BR or 6BRA next.

You do understand that you can’t just change the barrel? The .223 bolt face will not accommodate BR brass. You will need a different bolt or bolt head if it is replaceable.

 

[Raydee]

You do understand that you can’t just change the barrel? The .223 bolt face will not accommodate BR brass. You will need a different bolt or bolt head if it is replaceable.

Yes I completely understand

 

[mikecr]

Subsequent full length sizing should return the case volume to something approximating the new case volume. Yes the temper of the brass will change during subsequent firings, but that is an ongoing process and not pertinent to this discussion.

You're mistaken.
The character of brass affects the pressure curve.
You cannot restore brass character through FL sizing. In fact, you're continually changing it with FL sizing.
At best, but still unlikely, you might consistently restore dimensions with a custom FL die (in the long run).

It is very hard to deny, without a mountain of failed tests, that fire formed brass shoots differently (regardless of sizing).

 

[Bill Norris]

You're mistaken.
The character of brass affects the pressure curve.
You cannot restore brass character through FL sizing. In fact, you're continually changing it with FL sizing.
At best, but still unlikely, you might consistently restore dimensions with a custom FL die (in the long run).

It is very hard to deny, without a mountain of failed tests, that fire formed brass shoots differently (regardless of sizing).

Have to agree.

 

[Herzo]

You're mistaken.
The character of brass affects the pressure curve.
You cannot restore brass character through FL sizing. In fact, you're continually changing it with FL sizing.
At best, but still unlikely, you might consistently restore dimensions with a custom FL die (in the long run).

It is very hard to deny, without a mountain of failed tests, that fire formed brass shoots differently (regardless of sizing).

I understand (as you quoted me) that the temper of the brass changes as a result of the firing/resizing cycle (why else would you need to anneal?). But during the firing portion, the brass will expand to conform to the chamber and relax to some smaller size which allows for extraction. An over-gassed AR demonstrates this. Your thesis therefore posits that the pressure (energy) required to expand new brass is somewhat different and therefore lost within a closed but expanding cylinder.
As to the deleterious effects of full length resizing, there is no doubt that they exist and minimal working is preferred.
A relatively easy experiment would be to load 5 rounds each of new and once fored brass with the same (as near as possible) load and compare the results with a chronograph.

 

[Pres100]

A relatively easy experiment would be to load 5 rounds each of new and once fored brass with the same (as near as possible) load and compare the results with a chronograph.

Hasn't this been testing for multiple decades (or longer)? I guess it all depends on what you're trying to get out of your loads. My experience has shown there are slight changes from virgin brass to multiple firings. I don't think it's only the spring back of the brass but the internal volumes