fireformed vs virgin brass

[Koda]

Lets say you develop a load you want to use and want to produce larger quantities...
How much does virgin brass affect a recipe developed from fireformed brass?

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[RX-79G]

For a Ruger LCP, or a 1000 yard benchrest rifle?

How accurate is the fireformed load?

 

[Koda]

For a Ruger LCP, or a 1000 yard benchrest rifle?

centerfire rifle, for consistent accuracy and velocity.

 

[DizzyJ]

In my personal experience, it hasn't made much difference. Especially since I'm full length resizing.

 

[Koda]

In my personal experience, it hasn't made much difference. Especially since I'm full length resizing.

Do you do anything to prep the new brass or just load it up as is out of the box?

 

[DizzyJ]

Do you do anything to prep the new brass or just load it up as is out of the box?

Generally just run a carbide mandrel down through the mouth to ensure proper ID/neck tension.

I'd be curious to see what difference you find.

 

[RVTECH]

Do you do anything to prep the new brass or just load it up as is out of the box?

The one and only time I bought new brass I prepped it normally, FL sized & trimmed. It was not ready to load out of the bag.

 

[RX-79G]

centerfire rifle, for consistent accuracy and velocity.

I had edited my post, but the accuracy you're currently getting is part of the equation. If you getting 1" 5 shot groups at 100 yards, I doubt it matters. 1/2" and it might help.

 

[Koda]

The one and only time I bought new brass I prepped it normally, FL sized & trimmed. It was not ready to load out of the bag.

Do you only bump the shoulder back or do you size to the die?

 

[DizzyJ]

I would imagine most Virgin brass is undersized. That's been my experience so far anyway.

 

[RVTECH]

Do you only bump the shoulder back or do you size to the die?

I full length sized it, like I do everything.

 

[Koda]

I would imagine most Virgin brass is undersized. That's been my experience so far anyway.

In my limited experience this is what Im finding too, even below saami spec, and includes full length sizing dies. Which is why Im curious how much the fireforming part takes away from velocity or accuracy, as Im learning to control my shoulder bump process.

 

[DizzyJ]

In my limited experience this is what Im finding too, even below saami spec, and includes full length sizing dies. Which is why Im curious how much the fireforming part takes away from velocity or accuracy, as Im learning to control my shoulder bump process.

Try it out and let us know what you find.

I know that case will rapidly expand to fill the chamber.

 

[Koda]

I'd be curious to see what difference you find.

I will find out eventually but I think for my current beginner level of shooting it wont matter much but might as I improve my group sizes (nod to @RX-79G comment above). What Ive been thinking of is ordering some really cheap bullets to use just for fireforming but not certain if its worth it yet.

Generally just run a carbide mandrel down through the mouth to ensure proper ID/neck tension.

All I have is a Redding FL die. Ive just recently become aware of other dies that use bushings to control neck tension and not certain yet if I need to invest as Im still learning basics of sizing and working my ES and group size down.

 

[DizzyJ]

I will find out eventually but I think for my current beginner level of shooting it wont matter much but might as I improve my group sizes (nod to @RX-79G comment above). What Ive been thinking of is ordering some really cheap bullets to use just for fireforming but not certain if its worth it yet.

All I have is a Redding FL die. Ive just recently become aware of other dies that use bushings to control neck tension and not certain yet if I need to invest as Im still learning basics of sizing and working my ES and group size down.

I've generally avoided neck sizing due to the fact that unless your neck has zero thickness variation, you're just pushing the irregularities back into the inside of the mouth and making the outside round.

If a guy were to neck turn or have perfect neck thickness consistency, then I might be more convinced of its benefit. Otherwise you're using the bullet to form the inside of the case mouth.

IMHO of course.

 

[Koda]

Try it out and let us know what you find.

I know that case will rapidly expand to fill the chamber.

Ive found that minor dents form right out and doesn't seem to affect performance but I don't see how much larger brass movement from way undersized (virgin brass) geometry to chamber geometry doesn't take away from pressure.

My dilemma is I'm using expensive hunting bullets for my load development and realize the learning curve is more expensive. But I don't want to invest in cheap bullets if it doesn't matter.

It will be a few weeks before my next range session the rest of this month it full now with turkey hunting, company, and a home upgrade project. hate it when other things get in the way of target shooting.... well, maybe not turkey hunting

 

[Member 34319]

Only thing I do with brand new rifle brass is load it. The very first time I bought new rifle brass I ran it through a neck sizer, but after that I realized it is sized correctly and stopped doing that. If there are any minor dents in the neck, they come out when a bullet is seated. If you are using flat base bullets, you might want to correct the minor dents, otherwise anything with a boat tail needs no additional steps in my opinion.

 

[BigGame]

In my experience your velocity will drop using new brass with an established load. It will likely affect accuracy negatively also, but you won't know until you test it.

If you're trying to be frugal with components, prep a small sample using new cases and a range of powder increases. Maybe +0.4 grains of powder, 3 shots each, up to +1.2 or 1.6 grains. See if any of those trials returns comparable velocity and accuracy. If one does, call that your fire-forming load for new cases. Don't be surprised if it's not quite as good as the original with formed cases.

In reality, I don't think true load development for accuracy can really begin until you've fully formed the cases. But it all depends on the accuracy you're satisfied with and your willingness to expend components to get there.

 

[Xmark1]

Lets say you develop a load you want to use and want to produce larger quantities...
How much does virgin brass affect a recipe developed from fireformed brass?

There are many variables in play here.

It will always make a difference, virgin vs fireformed. However, the distance you shoot is part of the equation also. Environmenntal's during TOF affect POI.

I have found that Nosler brass is the best brass, right out of the box - much better virgin tolerances than say, Lapua.

Also, F1 - F2 - F3 - etc. makes a difference. Neck concentricity might change or stretch.

New vs old rifle chamber, degree of throat erosion, preferred trim length, projectile weight & ogive, BC.

We can split hair all day here.

 

[Koda]

In my experience your velocity will drop using new brass with an established load. It will likely affect accuracy negatively also, but you won't know until you test it.

If you're trying to be frugal with components, prep a small sample using new cases and a range of powder increases. Maybe +0.4 grains of powder, 3 shots each, up to +1.2 or 1.6 grains. See if any of those trials returns comparable velocity and accuracy. If one does, call that your fire-forming load for new cases. Don't be surprised if it's not quite as good as the original with formed cases.

In reality, I don't think true load development for accuracy can really begin until you've fully formed the cases. But it all depends on the accuracy you're satisfied with and your willingness to expend components to get there.

Im still fairly new at this but this is my guess that new brass will reduce velocity with an established load. Since my application is hunting Im using expensive premium hunting bullets so Ive been contemplating buying some cheap bullets just for fireforming. Ive also thought about working up to a "new case" load recipe but decided that if there is that much of a difference then I would just fireform them first with the cheap bullets. Being new, I just dont know first hand and as usual... in my rifle it might not be a big enough difference.