.300 Win.Mag. Brass question.

[mikenbarb]

I am reloading 300 Win.Mag. and wondering if its better to resize FL or just necks. I am shooting out of a Remington 700 BDL. So far the ones I have neck sized are working fine but im wondering about as they get shot more if the cases buldge and need to be resized. Also, I have some used cases that I got from a person and noticed some weird looking almost like tiny indented snail track above the belting on the bottom(almost looks craked but its not). Is this from the factory from their manufacturing process(flux line?) or is this something that is bad and they are garbage? Please answer only if you know for sure and not just guessing. Thanks, Mike
Forgot to add that the manufacturer in question is Winchester(W-W Super type)and all other brands are fine.

[Kobra]

Don't know about the last part, but I think most will recommend just neck sizing unless by some chance you are feeding a semi auto, namely a BAR.

[Sevens]

Benelli makes a barrel in .300 WM for their new R1 rifle. I think Winchester's new autoloader (Super X rifle?) is available in .300 WM as well.

I'd bet all of those rifles would be pretty hard on .300 WM brass.

[The Lovemaster]

You should be able to get by with neck sizing for several loads or more if they're always fired in the same gun (nice gun, BTW, I have a couple). Regarding the lines on the cases, I would straighten out a paper clip, then bend it into a small "L" and run it inside the case to the bottom. If you can feel the crack on the inside, then the case is NFG.

[Clark]

For the fine points of accuracy, look at Google groups advanced search in old rec.gun posts by Bart Bobbit about competing with the 300WM and what was learned.

For less fine points, look at me.
I have tried cutting the belt relief in the chamber .005" deeper than the reamer would, so i can get the shoulder to resist the firing pin force on the first use of the brass. I have tried FL sizing. I have tried neck sizing. I have tried partial FL sizing. No matter what I do, I still always get 1.5 moa from 300 WM.

[mikenbarb]

Just to give an update. I tossed out the few cases that were in question and came across 200 NIB Lapua cases for $70.00(Yes, 70 bucks!) My old friend thats a gunsmith is closing shop and retiring and he is letting me rummage thru his back room for whatever I want. After blowing dust off of alot of boxed I have come up with some realy cool items. Another item that i got is a few NOS boxes of original Failsafe bullets and half a shoe box of various dies. I am going thru all the stuff and will eventually post a WTB add for the items I wont need or the things he wants to sell. Have a good weekend and thanks for the help, I very much appreciate it, Mike

[R.Childs]

Check the inside of the casing where you see the markings with the jim clip. If you feel a groove then you have excess stretching.

I would continue to necksize till the bolt is stiff to pull up or push down. At this point, the shoulder will need to be bumped or setback. You can get a redding body die cheap for this procedure if you don't already have one. You need to get some case gages such as Sinclaire or Stony Point, which I think now are Hornady since they bought Stony Point out. Set your bump die to bump the shoulder back .001" to .002". This will be sufficient to free up the bolt while setting your shoulder back a minimum to prolong your case life. Even if you full length size, you can still set your die to just bump that shoulder. If you set your die per the instructions then you will set the shoulder back several thousandths and then upon the next firing the brass will stretch that amount. Do that a couple of times can lead to casehead separation.

Be sure to check those casings for a groove though. Casehead separation can ruin your day, not to mention your rifle.

[Shoney]

For some good pictures of what R.Childs is talking about:

Go to Steve’s Pages, you will find some good pictures, especially the cutaway showing the paperclip tool in use.
http://stevespages.com/page8.htm
Near bottom of main page go to Table 3, click
On Table 3 go down to Case information and click Diagnosing Problems

[HOGGHEAD]

I will not addres the problem with the brass other than to say this, if I have any question at all then I throw them away.

As far as sizing is concerned. What do you use the rifle for?? If it is a hunting rifle that is used in the mountains. Then I would recommend FL sizing strictly for flawless functioning reasons.

If you are a paper puncher then Neck sizing is fine to prolong the life of your brass.

Some reloaders believe that neck sized reloads are more accurate than FL sized reloads. My only comment is that properly done FL sizing can yield very accurate ammunition. That is the best way I can make a comment and stay out of any arguments.

Neck sizing can also yield very accurate loads. But neck sizing can yield problems while in the field.

Accuracy is great. But hunting accuracy with flawless functioning is truly more important. Tom.

[mikenbarb]

I am using the ammo for dual purpose. I reload the same bullets I punch paper and hunt with. I tossed the cases in question because im new at this and not ready to start guessing at things im not familiar with yet. I hooked up with a local reloader thats going to let me look over his shoulder and get advice and answer questions.(I got lots) Hopefully this will help cure me with the obsession I have for the "perfect" round.(my wife is getting jealous) lol

[Sportdog]

My thinking is in line with Hoghead. For hunting loads and hunting load development I was always told that I should full length size my brass. Neck sizing is for the paper punchers and those who want maximum life from their brass. Also if you plan on using your ammo in more than one gun you need to full length re-size. To be sure of proper chambering in mutiple rifles of the same caliber you wll almost need a small base sizing die as I found out when trying to use some mild reloads in a new 30-06 that were full length sized. About half of the cartridges, even though they were full length sized, would not chamber in my new rifle. Since the rounds that would not chamber were in the same box as the ones that would it kind of surprised me as I'm 99.99% sure that they were all reloaded from the same rifle, they are the same brand of brass, and they were all run through the same set of dies. My first thought was maybe the case OAL was too long due to necks that needed trimming but I found no difference in the brass neck length or the OAL of the loaded cartridge. I really don't know why they won't chamber unless the shoulder set back was for whatever reason was not achieved. Anyone else have any thoughts or experiences such as this? Just my thoughts and confusion!

[sc928porsche]

Neck sizing gives better accuracy and helps keep case life up. Do keep in mind that those cases, once fired in your rifle, fit YOUR rifle, and not necessarily others. If you come across used brass, be sure to FL size them untill they have been fired in your rifle for that very same reason.

Enjoy the fun and sense of accomplishment from producing you own "fodder".

[Hoss52]

My 300 win Mag has a tight chamber, so it requires full length resizing. Even so, I cycle every round that is going on a hunt, just to be sure.