300 win mag


September 21, 2008, 06:37 PM
just started to load 300 win mag and i didnt know that those cases are different to load. I guess with any belted mag case,when the case expands just above the belt that its too tight to chamber in the gun the cases are no longer useable, just learned that . I thought i got a good deal on 200 used cases but all i got was scrap brass. i even tried small base dies an still would not chamber in the gun. anyone else have any ideas?:cuss:

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September 21, 2008, 06:45 PM
Are you sure?
See what is tight, where?

Color a sized case with a black Magic-Marker and try to chamber it.

Then there is this, if it turns out you really do have a problem and not a mis-adjusted sizing die.



September 21, 2008, 06:51 PM
When you setup the dies, did you raise the press up to the highest position and then screw the sizing die down to it all the way as far and you could screw it in, then lower the press AND tighten it another 1/4 turn? I had this problem when I loaded .223, but I haven't started loading for my .300 yet.

September 21, 2008, 07:30 PM
yep set dies up, got all the case i could in the die still would not chamber case, check out the web site an the collet die should be the right answer..thanks for your help i am going to give it a try...

September 21, 2008, 07:32 PM
Many times, once fired cases need to be trimmed. If the case is too long, it might not chamber correctly. One other thing to check.

September 21, 2008, 07:38 PM
tried trimming 12 thousnds under still same problem:cuss:

September 22, 2008, 04:47 AM
OK stupid question from me...

Are you full resizing or neck sizing?

Also have you tried annealing the cases?
I have had sticky cases in my .300 but after full resizing the problem went away. Am using Redding dies...

September 22, 2008, 06:47 PM
yeah if your are not full length resizing that could be a big problem....because the used brass could have been fired in a loose chambered gun...which would be kinda rare since the only .300-win mag has been in bolt guns.

September 22, 2008, 09:29 PM
Hey Afy,

How many uses do you get out of your 300 brass? Just curious.

September 22, 2008, 11:11 PM
OK I have a Savage 110 and a Thompson Encore both in 300 win and both are pretty different. With my Thompson I get a lot of case stretch and end up trimming the brass down and can't reload the brass say more than 3 times due to case stretch at the band. My savage is a tight little thing and I dont get any trouble from the brass. I have 2 different sets of Dies for these two guns and I have invested in Norma brass. The Rem brass just doesnt hold up and the Win brass I have bought seems to last just a bit longer. I load them with 180 Sierra Boat Tail Custom with IMR 4350 powder just below max load. My guns seem to like that load.
Savage Model 110 Tact HB on a CHOATE ultimate sniper stock. I have installed a King Armory 1830 brake

Thompson Encore HB with the Encore recoil package and a King Armory 1830 Brake.

I have found that starting fresh with the brass makes the difference and I never mix the brass from the two guns. I would go down to sportsman or Bass pro and pick up a bag of win brass and start with brand new brass to get an idea what os going on with your gun. Or order NORMA or some other high end brass off the net. Anyway good luck.

September 22, 2008, 11:19 PM
Hey There ;
Is your head space right ? It sounds as if the head space may be why you can not chamber. If you sized full length and still can not chamber, your head space is too long.

September 23, 2008, 05:28 AM
Lgbloader I currently have a small batch of 20 which has been fired six times, and loaded 7.
I did full resize and anneal at #5.
Am shooting the 300 these days as I pulled the scope for my .260

September 23, 2008, 09:21 AM
I did a bit of a torture test on .300 WM brass not too long ago. I had 20 pieces of Hornady (Frontier) brass. I was very diligent about trimming and only neck sized them. My load was a moderate one running a 168gn bullet at just below 3000fps. Same load every time. I got 27 firings out of them. Well 26. On the 27th run, I split the neck on 13 of the 20. I believe if the cases are well maintained and not run "super hot" they will last a lot longer than many think. Just my experience, but I was curious.

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