Having problems w/ 300 Win Mag
08-05-2003, 11:27 AM
#1
Thread Starter
Join Date: Jul 2003
Location: Tulsa, Oklahoma
Posts: 1,051
Having problems w/ 300 Win Mag
Myself and a buddy chipped in together and bought a Hornady progressive press and have been loading for awhile now. The only problem we' ve run into is with the 300 Win Mag loads. We can only get them to go into the rifle properly if we use Hornady brass.
With any other brass we use, they won' t allow the bolt to close. We' ve measured overall length, case length, shoulder, case diameter from mouth to belt, wall thickness, everything!!! But we cannot find the problem. We' ve tried Winchester, Federal, and Remington brass. Dimensional wise, they are the same as the Hornady when we' re done trimming and sizing.
I might note, the loads with the hornady brass are tack drivers.
We' ve loaded .270, 30-06, and .45 acp rounds with no problems.
Any ideas?
With any other brass we use, they won' t allow the bolt to close. We' ve measured overall length, case length, shoulder, case diameter from mouth to belt, wall thickness, everything!!! But we cannot find the problem. We' ve tried Winchester, Federal, and Remington brass. Dimensional wise, they are the same as the Hornady when we' re done trimming and sizing.
I might note, the loads with the hornady brass are tack drivers.
We' ve loaded .270, 30-06, and .45 acp rounds with no problems.
Any ideas?
08-05-2003, 12:24 PM
#3
Nontypical Buck
Join Date: Feb 2003
Location: Western Nebraska
Posts: 3,393
RE: Having problems w/ 300 Win Mag
Several questions: Are you buying virgin brass and loading it or are you shooting the factory rounds in your .300 WM first?
Your gun: is it a factory made gun or custom chambered by a smith?
Are you full length resizing?
Whose dies are you using?
The .300 Win Mag headspaces on the belt like most belted cartridges.....these cases can also contact the chamber first on the shoulder just behind the neck and bullet. I had this happen with a .257 Weatherby....I thought my die was bad and I returned it to RCBS and they checked it and said it was good.
Have you taken a full length sized (empty) case that normally wouldnt fit the chamber and cut the case in half totally eliminating the foreward shoulder and neck to see if it does chamber under that condition?...If it does then there' s reason to believe your chamber is short.
Your gun: is it a factory made gun or custom chambered by a smith?
Are you full length resizing?
Whose dies are you using?
The .300 Win Mag headspaces on the belt like most belted cartridges.....these cases can also contact the chamber first on the shoulder just behind the neck and bullet. I had this happen with a .257 Weatherby....I thought my die was bad and I returned it to RCBS and they checked it and said it was good.
Have you taken a full length sized (empty) case that normally wouldnt fit the chamber and cut the case in half totally eliminating the foreward shoulder and neck to see if it does chamber under that condition?...If it does then there' s reason to believe your chamber is short.
08-05-2003, 06:07 PM
#5
Thread Starter
Join Date: Jul 2003
Location: Tulsa, Oklahoma
Posts: 1,051
RE: Having problems w/ 300 Win Mag
Now that' s not fair. You' re not supposed to ask me more questions than I asked you!!! 
We size down to the belt, but stop short of the belt by .0001" . Yes we use a full stroke down to the plate. The dies are Hornady. Yes, we shoot the factory ammo, then reload the brass, both with Hornady and the others. It does it in two different rifles. One is a Browning M1000 Eclipse, the other is a Browning White Gold Medallion. My buddy forgot to lube a case one time and got it stuck, then ruined the die trying to get it out, Hornady sent a new die, but the problem still exists. We kept the brass from our rifles seperate, but I don' t see what that has to do with anything if we' re full length resizing. We haven' t measured the diameter behind the belt. And no obstructions on the bolt faces. We both keep them clean. And, I' m sure we' re not setting the bullet too far out as empty, resized, cases won' t work either. I don' t have a shoulder angle measuring tool, but when we eyeball the case that won' t work, with the cases that will, there' s no visible difference that we can tell such as lengthening the shoulder.
Did I answer everything? Now you see why we' re kind of frustrated. [:@]
I noticed that the Federal brass seems a little more stout (maybe thicker or different grade of brass) than all the others.
Thanks for the help guys.
We size down to the belt, but stop short of the belt by .0001" . Yes we use a full stroke down to the plate. The dies are Hornady. Yes, we shoot the factory ammo, then reload the brass, both with Hornady and the others. It does it in two different rifles. One is a Browning M1000 Eclipse, the other is a Browning White Gold Medallion. My buddy forgot to lube a case one time and got it stuck, then ruined the die trying to get it out, Hornady sent a new die, but the problem still exists. We kept the brass from our rifles seperate, but I don' t see what that has to do with anything if we' re full length resizing. We haven' t measured the diameter behind the belt. And no obstructions on the bolt faces. We both keep them clean. And, I' m sure we' re not setting the bullet too far out as empty, resized, cases won' t work either. I don' t have a shoulder angle measuring tool, but when we eyeball the case that won' t work, with the cases that will, there' s no visible difference that we can tell such as lengthening the shoulder.
Did I answer everything? Now you see why we' re kind of frustrated. [:@]
I noticed that the Federal brass seems a little more stout (maybe thicker or different grade of brass) than all the others.
Thanks for the help guys.
08-06-2003, 06:43 AM
#7
Join Date: Feb 2003
Location: Rocky Mountains, Colorado
Posts: 1,964
RE: Having problems w/ 300 Win Mag
Danny45,
Consider picking up an RCBS precision mic chamber for the 300 Win Mag. It will tell you if your individual cartridge is in compliance versus SAAMI spec and if not then how many thousandths you are off by (in either direction). It will take into account the cartridge' s shoulder and belt as well. Be sure to mic the ones that work as well as the ones that don' t and note the difference in thousandths. At first blush, it sounds like it may be the die or the adjustment of the die.
Just on a hunch, before spending $$ or asking for refunds/exchanges, consider mounting the full length resize die in your old " one at a time" press, adjust it firmly and see if the problem persists. As stated above, borrowing someone else' s 300 win die and cross checking is a good move.
Best Regards
EKM
Consider picking up an RCBS precision mic chamber for the 300 Win Mag. It will tell you if your individual cartridge is in compliance versus SAAMI spec and if not then how many thousandths you are off by (in either direction). It will take into account the cartridge' s shoulder and belt as well. Be sure to mic the ones that work as well as the ones that don' t and note the difference in thousandths. At first blush, it sounds like it may be the die or the adjustment of the die.
Just on a hunch, before spending $$ or asking for refunds/exchanges, consider mounting the full length resize die in your old " one at a time" press, adjust it firmly and see if the problem persists. As stated above, borrowing someone else' s 300 win die and cross checking is a good move.
Best Regards
EKM
08-06-2003, 01:18 PM
#9
Nontypical Buck
Join Date: Feb 2003
Location: Western Nebraska
Posts: 3,393
RE: Having problems w/ 300 Win Mag
If the ammo originally fit into the gun and was fired, it means that the gun is probably fine and the brass is fine. Even if you don' t full length resize the brass should fit back into the gun!!! The bolt might close snugly....but it should close.
As you know, resizing (as well as firing) lengthens the brass...causes it to grow. I now believe your die is too long in the foreward end of the chamber allowing the brass to lengthen and then not fit back in the chamber.....However why one brand of brass doesn' t respond that way.....and my explanation don' t explain that.
As others have suggested....borrow another .300 Win Mag from someone and try it....I think you have a bad die!!
As you know, resizing (as well as firing) lengthens the brass...causes it to grow. I now believe your die is too long in the foreward end of the chamber allowing the brass to lengthen and then not fit back in the chamber.....However why one brand of brass doesn' t respond that way.....and my explanation don' t explain that.
As others have suggested....borrow another .300 Win Mag from someone and try it....I think you have a bad die!!