.300 Winchester Magnum brass differences & prep of same. Questions throughout .

Amanda4461

Loves Dobermans!
Full Member
Minuteman
Nov 11, 2009
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400
Asheboro, North Carolina
Hope those of you that shoot the .300 Winmag can either help me out, or cry in sympathy.
So, I sit down in my ez chair, lean back and grab a bag or box containing 50 new brass. TV is off. Wife is reading her smut book. Dobermans are snoring. Life was great till I looked at my flavor of the month brass. Winchester? Comes in a heavy bag like the Dobe’s food. Re-sealable for some reason. Case mouths are all lopsided and/or dented, so I cannot chamfer them till I run them over the expander button. No problem, I’ll just uniform the flash hole. Well, if I can find it. Winchester might have a centerpunch that is lined up on a center, but the machine that punched these holes is all over the map. I use a Hornady flash hole uniformer. It has a stepped plug that fits into the case mouth, in any of the superior cases, the stepped plug centers the uniformer button in the flash hole. Not with Winchester brass it doesn’t. What normally takes me 15 minutes for 50 virgin brass, takes 35 to 40 minutes with Oliver’s finest. I guess the uniformer won’t center into the flash hole since every damn case neck looks like my uncles chicken, after he rung its neck. Shit. Winchester goes on the shitlist. Fits at the top, below which sits PPU with 10-15% lopsided case necks. Federal, might be good to go, as long as I buy it from Midsouth or Bruno’s. Midway packs it so sloppily, it will look like shiny Winchester brass, with the case necks that are warped. Hornady? Comes in boxes in 5.56mm, great stuff for case prep, even if it does expire too early. If I ever find it in .300 Winmag, I hope it comes in boxes. Nosler I cannot find, but if I remember correctly, it is nice brass shipped in boxes. Lapua? Never have I seen any other than .375 caliber. No thanks to that one. IF Lapua actually makes their fabulous brass in.300 Winmag, maybe somebody can tell me where to locate a couple hundred virgin examples? I think it may be a Unicorn.
I normally find myself running a hundred virgin brass over an expander button, with the sizer die backed off, so that the neck doesn’t get touched. I read of Mandrels, but don’t know if it is the same philosophy, or an entirely different tool? If a tool, is it better than the sizer button? If so, best place to get one?
Normally, once the necks are uniformly round, I uniform the flash holes, then seat the primers by hand. I weigh each load of powder, double-check on a different electronic scale, then seat the bullet a few thousandths off the lands. In my newest rifle, this gives me a loaded cartridge overall length of 3.517” from bullet tip to base of cartridge. By collimator, I have 3.750” coal. The manuals state 3.340” as max coal? My rifle uses AICS mags, allowing greater length, up to 3.80” or near that length. Hope I am doing the right thing here. I am used to loading 5.56mm to max length allowed by the magazine. Bolt gun is a new thing. I have the equipment for neck sizing or full length. Coming from using Small Base full length dies, I’ll have to maybe try the neck sizing route.
I would like to get the greatest amount of loads per case possible. Any suggestions on the best case for doing so, as well as the best resizing method to use? Rifle is used for steel or paper. This is retirement relaxation only. No competition, as I use pistols for that. All suggestions greatly appreciated. Thanks!
 
That’s a lot to read!!

I use Nosler Brass
Lee Collet Die
Redding body die

200 ELDX/CCI 250/Nosler Brass/H4350

.030” off lands
.002 off shoulder
 
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Plus one on the wall of text. Here is the load I developed my mod 5:

220 smk
H1000 (76.2g - work up to something like this!!)
Fed 215M primer
Federal #14 case (mil)

Prep:
Brass sized .002chamber-shoulder clearance (Redding Ultramag press)
Primer pockets uniformed w/Sinclair uniform tool
Cases trimmed if necessary
Chamfer applied

Seating:
Bullet jump: .030” on a Forster coax using Redding BR seating die

Performance last random 5 round group:
Mean MV: 3035 fps
SD: 8.9 avg
ES: 21
 
Dear Diary,
.........

Great your thinking out loud but we have small attention spans here. Sum up concisely what your question is and alot will chime in. A To Long Dont Read style summary would help.
 
I use the WW for my 300wm and have been for roughly 3 years. When Nosler became the unicorn you speak of, WW was all I could find so I went with it.

Although it definitely takes much more work to prep the brass, it’s half the price and easy to find. I found it easiest to use a mandrel to straighten out the necks and usually end up losing half a dozen or so per bag, but after the first prep, my brass has been reloaded over 5 times before I chuck it. With the proper prep and tuning, I’ve been successful at holding a 5-6 SD.
 
Check out ADG brass. This is some of the nicest brass I have used. A little pricey, but I don't do anything but open the box, check fitment in an L.E. Wilson case gauge, and start seating primers. It's a little thicker and heavier than most commercial brass, so if you're using a maxed out recipe with commercial brass, you'll need to back it down and work back up.
 
feel thenops pain. i have some old remington brass i am still working through. always heard bad things about the winchester and stayed away. have hornady, nosler and normas. working in normas now. dont seem as 'thick' as the rem's but time will tell how they hold up. like OP i would be all over lapua if it existed.
 
feel thenops pain. i have some old remington brass i am still working through. always heard bad things about the winchester and stayed away. have hornady, nosler and normas. working in normas now. dont seem as 'thick' as the rem's but time will tell how they hold up. like OP i would be all over lapua if it existed.
If you get the chance, check out that ADG stuff. IMHO, it's the American-made version of Lapua. Probably a little cheaper too. I bought some from a place called creedmoor sports and was blown away at how nice it was. Got more on the way.
 
If you get the chance, check out that ADG stuff. IMHO, it's the American-made version of Lapua. Probably a little cheaper too. I bought some from a place called creedmoor sports and was blown away at how nice it was. Got more on the way.
I’ll give that a try. Creedmoor actually sells it at a lower price than Scheels, but both are out of stock , of course. I grew up in Kentucky, but never new that someone made rifle brass there. Guess I was too busy making gasoline and jet fuel.
 
Apparently, Lapua made 300 Win Mag brass. Or maybe they had someone else make it and the marked 'Lapua' on it.

ADG is your best bet these days. Nosler and Norma are pretty nice too. As you found out Winchester brass sucks these days.

To extend case life on a 300 WM case the biggest thing you need to do is don't push the shoulder back any farther than you need to. The 300 WM case is based on the .375 H&H case which was designed to headspace off the belt at the bottom. What you need to do as a reloader is headspace off the shoulder.

If you're using a Neck Bushing die that will help in reducing neck sizing.
 
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Here's your unicorn. I actually sold this here a while back. But there is still some out in the wild.
From what I learned, it was made by Norma for Lapua. I never shot it or used it so don't know how it is, but for Lapua to put their name on it, had to be decent quality. Bruno's had some Norma a week or so ago, but they are all out now. So need to keep checking for that.

I'll have to think, I have always wanted to try some of the .Mil 300 WM brass, but haven't seen what they use for sale anywhere.

I am still using some old Norma brass that I had, it keeps working for what I use it for.

I have used some older Winchester brass, but I always bought it once fired from other people and usually for a good price.

Like others have said, heard good things about ADG, Nosler, Norma.
 

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Adg or gunwerks ive had terrible luck with norma lately in a 7mm rem. The gunwerks holds better pressure and is really tough stuff best brass ive tried so far im pretty sure adg makes it but not 100 percent sure
 
I have about 100 pieces of Lapua 300 Win Mag. Bought it from New Zealand several years ago - $150/100 pieces. It is good stuff, very uniform, but fairly light and high pressure blows out the primer pockets. I have a tool to improve that but it has limits. I have a few hundred pieces of WW mil brass. It is the best in my rifle. I tried some of the Federal mil brass, didn't care for it, too soft for me. FWIW, I now anneal every firing.

Full length expanders work because the die squeezes the neck down and the expander expands the neck when you withdraw it through the reduced neck. Standard full length dies reduce the neck quite a lot then expand it quite a lot so there is quite a bit of force to pull the case over the expander. If the force is enough, the neck may be pulled away from the case base making the case longer. Not just longer but the length is less uniform. Some people have reported that the force also distorts the neck so that it is no longer exactly concentric around the long axis. The concept is that the expander plus spring back will make the neck just right. I always thought there was too much neck tension.

When you use a mandrel, there are two operations (1) squeeze the neck with a button and bump the shoulder then (2) where you force the case over the mandrel. The concept is that the button makes the neck just a little smaller than it needs to be and the mandrel expands it just a little and pushes the doughnut to the outside - less working the neck brass, both circumference and along the case long axis. Since the doughnut is forced out, the neck inside is smoother and seating force is more uniform than just using the button. I find that "mandreling" works better if I use graphite powder to lube the neck. Others use other stuff, same idea.

I have mandrels from 21st century and Sinclair - both good, both work.

if you buy a mandrel and you want more neck tension, you can chuck it up and reduce it with sandpaper. Oddly, when I got carried away I haven't found a way to make it bigger. Something to keep in mind.