Virgin brass, or once fired!

[Autorotate]

Somewhere in the mix, the whole meaning of this thread got lost. I've loaded and shot for more then 40 years. In that time, with various rifles, brass, loads etc, I've run across this, " PHENOMENON ", on occasion. The load, that was fired, in the virgin brass, was a predetermined load, that the rifle liked, that was simply put together, with virgin brass, sometimes processed, sometimes not.
My question was, and is, have any other members noted that before, what if any thing do you think, is the reason.
Not that you can change it, the brass is now once fired.
It's not about seating depth, headspace, or load data. That's already been determined.
Thsts as clear as I can put it. Sorry if it came out any different!

I've seen this same thing. Sometimes when FF a wildcat I could achieve tighter precision with less effort than with the formed case. And with SAAMI/CIP chambers sometimes same thing. A few of the occasions, I discovered there was a factor(s) I wasn't managing properly when firing the second firing, ie barrel bore condition, brass headspace or neck tension, annealing, etc, and I can often tweak the various factors to get formed to shoot as good or better than virgin. But sometimes, not...theory would be all I'd have to offer, in that a virgin informed case acts as a "pressure accumulator" of sorts and alters the progressive part of the burn curve, and subsequent pressure spike/waves...but that's all that is ... conjecture. And in those barrel/powder/bullet combos, that alteration of the initial part of the burn curve widens the node your on, and makes it shoot well. Of course the opposite can happen as well. All just conjecture obviously. I'd like to really know myself.

 

[DJ Fergus]

Somewhere in the mix, the whole meaning of this thread got lost. I've loaded and shot for more then 40 years. In that time, with various rifles, brass, loads etc, I've run across this, " PHENOMENON ", on occasion. The load, that was fired, in the virgin brass, was a predetermined load, that the rifle liked, that was simply put together, with virgin brass, sometimes processed, sometimes not.
My question was, and is, have any other members noted that before, what if any thing do you think, is the reason.
Not that you can change it, the brass is now once fired.
It's not about seating depth, headspace, or load data. That's already been determined.
Thsts as clear as I can put it. Sorry if it came out any different!

My apologies for running a rabbit. Yes, I've noticed it when I bought and loaded virgin brass. but I've never noticed that I couldn't get brass from once fired factory ammo to shoot great, but I worked up a load from scratch on the fired factory ammo brass. With virgin, I worked up a load that shot good and tweaked that load on the once fired brass. At times it shot just as good and at times it wasn't hardly as good. So, I believe I should have started over completely from scratch with the once fired brass that happen not to shoot hardly as well. But it may or may not have helped matters, IDK.

 

[freddiej]

7 STW, I have shot both through most of my rifles I own. in some guns virgin shot well but not nearly as good as my home brews with once fired or multiple fired brass. What I have found is if I keep the brass weights as uniform as possible the guns in my safe shoot extremely well. this has been my experience ever since I started shooting and reloading.

 

[Mikecr]

My question was, and is, have any other members noted that before, what if any thing do you think, is the reason.

Threads sometimes go roundy-roundy.
Sorry,, and back to 'the reason'.

There was a recent thread about brass weight: https://www.longrangehunting.com/threads/velocity-vs-brass-weight-experiment.242421/page-2
These threads are connected in that both end in the same room -> ENERGY USED TO COUNTER CHAMBER CLEARANCES.

In that thread, post #28, I laid out the same answer as later summarized in #37 here:
new brass expansion capping the pressure peaks to a consistent point, like a heavily diminished return

There is another area leading to the same room: THE advantage of underbore cartridges.

 

[MagnumManiac]

I will give you my theory as to why virgin brass that has had all necessary prep shoots tighter groups over once, twice or thrice fired brass.
After running all my test loads over a pressure trace in conjunction with a chrony, there is a pattern that emerged.
Virgin brass not only produces lower pressure and velocity, but also a softer and longer start pressure. It is this fact, particularly with all belted cases, that they shoot very good groups. I believe it is this softer less violent transition into the rifling that causes the best groups. Just like a reduced load often does the same thing.
Now, this is only my theory after using the pressure trace for many years now. I'll give another example, my 25-06 is very destructive on animals I wish to eat, so I developed a reduced load hoping it would destroy less edible meat and, to my surprise this load shot into one hole that you could not distinguish there were in fact 5 shots into it...it was also totally repeatable. Now, admittedly, my 25-06 is a tack driver anyway, averaging 1/4-3/8 MoA groups depending on bullet weight, but this is still impressive with a reduced load. My 45-70 also did the same thing.

Hope this is as clear as mud.

Cheers.

 

[ButterBean]

I will give you my theory as to why virgin brass that has had all necessary prep shoots tighter groups over once, twice or thrice fired brass.
After running all my test loads over a pressure trace in conjunction with a chrony, there is a pattern that emerged.
Virgin brass not only produces lower pressure and velocity, but also a softer and longer start pressure. It is this fact, particularly with all belted cases, that they shoot very good groups. I believe it is this softer less violent transition into the rifling that causes the best groups. Just like a reduced load often does the same thing.
Now, this is only my theory after using the pressure trace for many years now. I'll give another example, my 25-06 is very destructive on animals I wish to eat, so I developed a reduced load hoping it would destroy less edible meat and, to my surprise this load shot into one hole that you could not distinguish there were in fact 5 shots into it...it was also totally repeatable. Now, admittedly, my 25-06 is a tack driver anyway, averaging 1/4-3/8 MoA groups depending on bullet weight, but this is still impressive with a reduced load. My 45-70 also did the same thing.

Hope this is as clear as mud.

Cheers.

We are talking about Virgin Brass that has had No prep, straight from the box

 

[SmallHoles]

Except when you fire it drives the case forward and your shoulder to ogive is now the seating depth not base to ogive.

I wouldn't think this ever happens, if you mean that the entire case moves forward, because the extractor holds the base in place.

If you mean that the shoulder expands to fill the chamber and this moves the neck forward too, you may have a point provided this happens before the bullet starts to move.

I'd think pressure would cause the bullet to start moving before the case deformed but want to see test data before being convinced one way or the other.

 

[MagnumManiac]

We are talking about Virgin Brass that has had No prep, straight from the box

Really, who said no prep and straight from the box?? Definitely not the OP.
I have NEVER used brass straight from the box...dinged up necks will NEVER get a bullet seated in it for my rifles.

I don't know why you think you are the thread POLICE...please stop you are not helpful.

Cheers.

 

[greenejc]

Something has been bugging me about brass, virgin brass, either processed, or out of the box, versus once fired!
First of all, Butterbean , made mention of it in his thread, MY FIRST TIME, but I want to explore other people's thoughts, and experiences , with accuracy, from virgin brass, versus once fired.
I have had two rifles, in different calibers, that would , with virgin brass, shoot better groups, hands down, then it would with any combination of resizing, or lack of. Full length, partial, neck sized, didn't matter. It shot ok, but no where's near what the virgin did.
Secondly, do you shoot the whole box, or do do take out and shoot through a batch, then start over.
Thoughts and experiences appreciated!
Be safe All!

Nearly all the virgin brass I've used has had to be run through the sizing die for neck deformities anyway, so it doesn't really matter to me. I've gotten good accuracy with both new brass and once fired brass, but have found that different brass shoots differently, both in accuracy and in how much I had to prep it, regardless of the newness of the brass. Since I have a friend who volunteers to work at the public range here, and he gets me brass for free, I've been able to test various brands of brass for accuracy, and so far the winners are Remington, Winchester and Federal. That's in all the calibers I reload, with Winchester and Remington being about the same. Point of Aim with both Remington and Winchester are within 1/2 inch at 100 yards with the same loads, while Federal is generally within 1 inch, either up or down, depending on the rifle/caliber. As to new brass, I've used Remington, Winchester, Sig, Hornaday and Federal, and Remington seems to be the most consistent and accurate. It depends on how accurate you want to be, too. I'm fine with a standard weight rifle with a little tweaking that will hit a prairie dog at 250 yards, or give me sub moa groups with good hunting loads. I have to full length resize all my brass, since I have more than one rifle in nearly every caliber I shoot, though, so that makes a difference. This means that I pretty much need to have the same over all length with each load, and set it for the rifle with the shortest throat, but it has worked fine so far in both my .308's, all my 30-06's and both my 300 winmags. I haven't gotten my new 35 Whelen back from the gunsmith yet, but we tested it with the loads for my Remmie 35 Whelen (Stock CDL with only a trigger adjustment), and it shot about 1" in a 17 mph wind with gusts up to around 22mph. Can't wait to get it finish blued and to the range to really wring out the 1 in 14 twist barrel we installed. In the first rifle, new brass, old brass and brass made from 30-06 necked up all shot 1 inch or less with either the Speer 250 grain or the Sierra 225 grain bullet, with the 225 grain Sierra being the most accurate. I think the 1 in 14 inch Shaw barrel will put the Speer bullet into around 0.75 inches, though. And yes, since some of my brass for the .35 is made from necked up once fired 30-06, it is all full length resized and trimmed.

 

[ButterBean]

Really, who said no prep and straight from the box?? Definitely not the OP.
I have NEVER used brass straight from the box...dinged up necks will NEVER get a bullet seated in it for my rifles.

I don't know why you think you are the thread POLICE...please stop you are not helpful.

Cheers.

From the OP
"Something has been bugging me about brass, virgin brass, either processed, or out of the box,"
??????

 

[wonderman4]

I have never processed new brass. Back in the 60s, I bought new brass to the point of excess, and I still have some today that I have never loaded or prepped. I have always just loaded and shot it. I never even chamfered new brass.

I went into the stash not long ago checking inventory and I found 4 boxes (80 pieces) of 7x57 brass, 5 boxes of 8x57, 4 boxes of 30-06, 2 boxes (100 pieces) of 44 Mag plus some others.

With that said, I have never found the circumstances that you (the OP) are referring to.

 

[338 dude]

I will give you my theory as to why virgin brass that has had all necessary prep shoots tighter groups over once, twice or thrice fired brass.
After running all my test loads over a pressure trace in conjunction with a chrony, there is a pattern that emerged.
Virgin brass not only produces lower pressure and velocity, but also a softer and longer start pressure. It is this fact, particularly with all belted cases, that they shoot very good groups. I believe it is this softer less violent transition into the rifling that causes the best groups. Just like a reduced load often does the same thing.
Now, this is only my theory after using the pressure trace for many years now. I'll give another example, my 25-06 is very destructive on animals I wish to eat, so I developed a reduced load hoping it would destroy less edible meat and, to my surprise this load shot into one hole that you could not distinguish there were in fact 5 shots into it...it was also totally repeatable. Now, admittedly, my 25-06 is a tack driver anyway, averaging 1/4-3/8 MoA groups depending on bullet weight, but this is still impressive with a reduced load. My 45-70 also did the same thing.

Hope this is as clear as mud.

Cheers.

Finally something that makes sense with a less violent longer starting pressure. I have always seen a pattern your hottest loads are almost always not the most accurate and reduced loads seem more accurate,so I believe this backs up your theory

 

[26Reload]

I was shooting some new 65284 lapua recently......
and fliers...ugly stuff....but i sensed something was definitely off with the new brass....when loading the boattailed nosler 142lrab bullets there was definitely too much resistance...like you could have seated a .257 in it fine.....
Resized the necks and things definitely tightened up...
I would have to think too much neck pressure from the factory brass was being a pita.....

 

[Mikecr]

I have always seen a pattern your hottest loads are almost always not the most accurate and reduced loads seem more accurate

Not to go roundy again, or to police(I mean no offense), but accuracy in this does depend on the cartridge as well.

Underbores, 6PPC, 30br, etc. rely on extreme pressure loads. Competitive for 6PPC being upwards of ~75Kpsi!
This takes them so deep into diminished pressure returns that they don't even have to measure their powder..
After all, diminished returns also means diminished variance of returns.
Of course nothing about them relates to hunting capacity cartridges, where high pressures are not viable. But it relates to this. To pressures flattening (capped).