I sold my 7mm mag and bought a .300 win mag savage with the drop floorplate. I measured the length of the magazine compartment for the gun and and have a total length of 3.47 in. I am curious what overall length you are loading you guys are loading your .300 win mag ammo to. Details that would be helpful would be overall length and what bullet and weight. I will have my tool to measure chamber length to the lands in a couple days and would like to pick up some bullets based on what will fit into my magazine and hopefully be able to be seated into the lands.
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.300 win mag oal question
- Thread starter wpwarren
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baldhunter
Well-Known Member
It's really going to depend on your rifle.Every rifle is different.I have a Rem 700 that has a long throat and the mag box is around 3.6".My CZ 550 has a long throat and a mag box about 3.5".They both shoot best with ammo loaded @ 3.45-3.5".The books usually show 3.340",but my rifles never shot good at that length.Remember,pressure can build once you get real close or into the lands,so watch out for that.I like to stay at least .020-.030 off the lands to keep that from happening.I also prefer to use a Hornady bullet comparator to measure my cartridge length instead of measuring off the bullet tips which often vary.It measures off the ogive of the bullet.That is the part of the bullet that comes in contact with the lands first.I find my ammo has a very consistent length using the comparator and that is important when measuring bullet distance from the lands and setting up your seating dies for a specific seating depth.
Thanks for the response. I have a bullet comparator that I will use. I know it will vary, I was just trying to get an idea of what others were finding for a measurement that works. I will just buy some cheap bullets, measure the overall cartridge length to the ogive and then look up the data for various bullets from ogive to bullet tip. However, more peoples input is welcome.
kcebcj
Well-Known Member
If the rifle is for hunting start your load development with the longest length you can yet still fit the magazine. Purchase the bullet for what it will be used for (hunting target). All reloading books show the loads for the 300 WM using the COAL of 3.340 so most all bullets will work at that length.
Just remember when moving the bullet deeper into the case or moving it towards the lands there will be a pressure change. Any time you put the bullet tight against the lands there will be a spike in pressure of about 7,000psi so be aware of that. Start you load workup low when getting in close to the lands and have the tools to know exactly where the bullet is in reference to the lands.
With your mag at 3.470 I would start my load development somewhere around 3.400-3.450 (a judgment thing)and work back from there. Good luck.
On my Savage 111F in .300 WM, I keep it at 3.44" (base to tip of bullet) for proper feeding. My last load for this rifle was for .208gr A-Max using 73gr H4831SC.
Good luck!
Thanks for the response. Do you know how far off of the lands you are?
I understand the pressure issues, but they are important to consider. Your overall length suggestions seem like a safe way to ensure that the rounds feed through the magazine.
I was thinking about trying to do something like that. Do you have any pictures?
.020" off the lands for the .208 A-Max.
.02 off the lands and loaded to 3.44 sounds workable. I guess I should buy some heavier bullets and see how close to the lands I can get before I mess with extending the magazine.
Do those shoot well from your rifle with that jump?
