When using virgin brass, I've always shot the new batch with a medium load to fire form to the chamber of the rifle of interest. Doing some case measurements, I wonder if the initial firing is worth the effort/expense.

Do you develop test loads and/or use virgin brass as is for either/both purposes?

If it assembles into straight cartridges you can do good work with virgin brass. That said, I do like to check out the necks of new brass. I run the necks over a mandrel to round them out and see if they feel consistent. If two or three in the bag are loosey goosey I'll mark them with a Sharpie and use them for foulers on the first go round. If there is a lot of variability in the batch when they're going over the mandrel I'll size them down and expand the necks again. That's too much busywork for many here, but I find time at the loading bench to be relaxing.

If it's a new rifle to me and I'm starting with new brass I'll use it to test loads. I'll load up 5 rounds in each powder/charge weight that I'm testing and measure runout. I can almost always (with good brass) get 3-4 rounds with acceptable runout for accuracy testing. I'll also use a chrono, many times a particular powder won't get the velocities I'm looking for with the chosen bullet so I can eliminate that powder from further testing.

I’ve never done that. I chamfer the mouth of case, deburr flash holes, load them up, fire away. I’m a hunter, not a target guy. If I get an inch or less, I’m good to go hunting.

I use new brass just like 1x 2x ect

Good comments. Apparently I've over OCD on this...............

Depends upon the brand of brass for me. For Lapua I simply chamfer, load and shoot.


The above is virgin brass with simply the chamfer, load and shoot.

For other brands, I may go all out and FL resize etc.

It is a well established myth that you have to process new brass in some way before loading it. I'm a hunter but I also test my own loads and can shoot out to 400 yards on my property. I am not happy with a load unless it does better than 1 MOA for scoped rifles and handguns at 100 yards and usually do better. After having reloaded thousands of rounds:

1. If there is a problem with the mouths shaving bullets I'll chamfer new brass but that hardly every happens.

2. With the exception of 460 S&W Magnum cartridges to be loaded for a revolver I don't resize new brass, deburr primer pockets, etc. And guess what? New brass loaded that way shoots every bit as well as once fired brass and at times better.

3. If a case mouth is a little out of round and I'm loading boat tailed bullets I seat the bullets without doing anything to the case mouth. If a lot out of round, I use a screw driver to get a more reasonable shape and then seat the bullet.

4. As for fire forming new brass. Never. That said, when fired brass is resized and used again, the POI might be a bit different.

It is prudent to neck size the brass having uniform neck tension and straight neck walls. Running the brass over an expander ball is often all that is needed.

Also, a HEAVY chamfer acts as a bullet guide helping the bullet to get started straighter without deforming the base of the bullet.

New brass fire forming loads have less capacity than a fire formed cases, often you have to make an adjustment.

Lapua and Norma brass can be spectacular in quality.

I generally run new brass through my FL sizer to make the necks more uniform, trim (for square as much as length), debur / chamfer the case mouth, and generally debur the flash hole from the inside. I don't usually uniform the primer pockets unless a prior run of the same brass has shown marked inconsistency but I have the tools and I do occasionally use them. I also like to tumble the brass at least briefly to remove residual sizing / forming lube.

Tom

For some loads that would be otherwise heavily compressed I’ll fire new cases with a practice load to gain some more volume.

On occasion I’ll also run the expander ball down through the neck to true them up. If I have a lot that I notice has significantly different case neck tension, I’ll partially size them to get consistent tension.

I don't understand the logic of saving 10-15 minutes running a 100 brass through a sizing die vs the benefit of consistent seating depth with consistent neck tension.

For shooting known loads through new brass I found that the expansion will eat up the equivalent of about 1g of powder. In other words, if your loads require 60g of a propellant then you have to load new brass in known loads with 61g.

To test starter loads in a new barrel you can at least ball park figures for velocity using virgin brass.

When using a new batch of brass with a known load or barrel I always fireformed using COW, then manicured the brass and loaded as usual providing the brass was of equal weight to the old. If not, you have to work up your load again.

I go thru the multi-stage fireforming process in my 280, 280 AI & 300 WSM. In my 308’s, using Lapua brass, I neck size only. That’s all & thus far they have been comically accurate right out of the box.

^^^^^^ This is why I've always shot the brass in my chamber first. I've never tested it before but would think the difference in volume might change the accuracy of the load itself.

I’ve never seen a difference between good vigins in a properly cut chamber, and brass that's been fired.

Unless its a max or over max load I load new brass like I load fired brass. I resize all news brass and do some stuff to the primer pocket and chamfer the case mouth. I know the sizing did probably does not touch the shoulder and I don't really care but sizing takes the dents out of the case mouth.

Same as above load and shoot. As lightman said only those max compressed type loads won't be compatible with new brass. I prep all new brass the same except the flash holes on Lapua and RWS brass. Some like PP really need primer pocket work to ease head aches in primer seating. This is OCD but once and done so I won't wander if it was needed later.

Yesterday I finished cutting the primer pockets to correct depth for a batch of "red bag" Winchester brand 308 Winchester brass. For its first loading I had simply trued up the necks and assembled the cartridges. I could tell right then I'd be cutting them before the next loading. I was using S&B primers which have always seated nicely for me, but this time there were many cases that took a heavy hand on the priming tool to get things seated flush. Doing the prep for the second loading I cut them to spec with a Sinclair tool, and they really did need cutting.

Joe Average reloader who doesn't have "all those fancy gadgets" would likely be up the creek if his brick of primers happened to be Rem 9 1/2's which run tall in my experience.

I used to think I needed to fire-form virgin brass to the chamber before doing any serious load development. These days, I just run the expander ball in the necks to iron out any dents, then chamfer, load and shoot. I use virgin and / or previously fired brass for load work, hunting and everything else and don't give it any more thought.