Rick
The PPU brass was reloaded from purchased ammo, so i know it was fired in my rifle only, 3 times.
With the Lee Enfield in particular, the first firing is the key. With factory ammo, you either accept that as is because that factory ammo has most value because you like it's performance as is. Or you pull the bullets and charges, and load them in fireformed cases with your seating die set to the original O.A.L. cartridge length. Either pre-formed other cases, or use a method to fire form the PPU brass first.
I bought a whack of one lot of 1960's Greek HXP surplus ammo 30 years ago because the DCRA guys at the time were praising it, and it was dirt cheap. I used it to select the most accurate Long Branch from a lot of new ones that Districorp apparently found over in Belgium. The one I kept was extremely accurate with that ball, but I also wanted to get as much life as possible out of that brass.
So I knew what the rifle would group ten rounds of that ball at my local 300 yard range. I pulled down ten of the rounds, applied a false shoulder, reloaded with the original powder and bullet, and then fired that for comparison. The grouping wasn't quite as good - but not very far off. And I was happy because I had rounds good enough for at the very least practice, and primo fire formed brass to use with my commercial 174gr bullets and worked up loads.
So if you prize the brass, it's a pain in the ass, but you can pull the ammunition down, apply a false shoulder (or do the O-ring thing), and probably still get as good or almost as good target accuracy out of the factory charge/bullet.
I don't know how readily available PPU empty cases are these days. I bought a whack of them a few years ago when they popped up for sale. And the HXP, mostly, is still going strong. The last time I saw it come up for sale they were asking and getting $1/round.
The first time it was FL sized, the second and 3rd NS. The Winchester was purchased once fired (i am taking sellers honest about this, it was purchased with imperial brass, not used yet) so second time its FL and NS 3rd time.
So as you probably know, you're already starting out behind the curve. Particularly with the apparently once fired Winchester, which for all you know was originally fired in a rifle long overdue for a new bolt head.
I was just asking about the lines inside the brass to see if its some sort of indicator that the brass is failing, i purchased a lot of winchester and imperail (once fired) and can check inside the cases.
If I wanted to ensure I got the best out of that used brass I would first see if it would even chamber at all in my rifle in it's current condition. If it does, then that probably tells you at least it wasn't fired in a rifle with a much larger chamber than yours has. If it won't, you'll have to size it back to where it will chamber. That should give you something similar to a crush fit after applying a false shoulder; good enough, because most of the damage has already been done on the initial firing on another rifle with an even larger chamber.
If it does chamber as is, then I would apply a false shoulder so that the brass would only chamber with a crush fit - limiting any further significant case stretch other than that of the original firing.
Finally, I would anneal the case necks for consistent neck tension as well as to get rid of any case neck hardening that could lead to cracked case necks.
For checking inside the necks, I use the probe/pick from the RCBS dial indicator comparator tool to feel; not taking a look inside. If you ask your dentist nice, they will give you their dental picks or explorers or what they call them that they're about to throw out, those are nice and rigid to check for developing case head separations. Maybe like you do I should look as well (but my senior citizen eyesight sucks), but I haven't had a case head failure when I discard any case that fails the probe scratch test. If I saw those rings in your pics, I'd probably junk those cases. And maybe section them to see what was inside.
The RCBS dial indicator measurement tool may well be over the top for people who have less exacting standards to reach the point of fun with their rifles. But (as a relevant example), it can not only be used to detect the beginnings of case head separation, but give comparative readings for different brass from different manufacturers from the neck all the way to the web, at pretty much the exact same spot on all pieces of brass measured.
That happens to be a piece of new PPU .303 British brass from a lot I was applying a false shoulder to prior to first firing. You can see what looks like a little bulge before the actual factory shoulder that results from running (in this case an NOI neck expander die - great product and very inexpensive) a larger caliber neck expander die in the mouth, and then using a case mouth resizing die to size the false shoulder back to where the case will finally chamber again with a crush fit. As it was just sitting there, I just popped it into the tool for a picture.
While I was at it, I also put some 1968 HXP cases on the probe as well... They measure within a thou or two at the same point along the length of the case. (the dial indicator measurement changes a bit as you rotate the case 360 degrees around the probe, of course). These aren't also micrometer type accuracy measurements, but (this is a guess) accurate to about +/- .0015" - good enough for comparison purposes of wall thickness of different pieces of brass at the same point in the brass.
Might be way too anal and too much useless information for many people and what they're shooting and how they're shooting them. I find it useful. Not for every caliber, every rifle, and every kind of reloading, but it is regularly a useful tool to have on the bench.
The same techniques for case life/best fit also work for very experienced old rifles, like my Grandpop's old 1895 Winchester. I don't know what the bore measured when it was manufactured back in August of 1898 in 30 U.S. Now it has dimensions where bullets (jacketed or cast) intended for .303 British are far more accurate. Different issues, but same in that you don't want to unnecessarily size down/expand the case any more than necessary.
