Whats the difference between the 300 Mag & a Weatherby 300 ?
The difference in carthage size.

Thank You

Which 300mag? 300RUM, 300win mag, 300HH mag, 300norma mag, 30-378weatherby mag, 300WSM, on and on.

Is this a reloading question? ARe you asking about loads for each?

I suggest going to the following. webpages. they have several of the 300mags andyou can compare various loads, and thier velocitys.

http://data.hodgdon.com/cartridge_load.asp
www.alliantpowder.com

I'll assume the .300 Mag you're talking about is the .300 Winchester Magnum since that's what most people think of when you say "300 Mag".

Here's what I can tell you. They're both based on the same parent case, but the .300 Weatherby is longer and therefore has a little more case capacity. The larger case holds more powder which translates into a little more velocity, maybe 100-150 fps for the same bullet weight vs. the Winchester mag. In a .300 Wby you could probably get 3200+ fps with a 180 gr. bullet. In the .300 Win. mag you'd probably max out at 3100 fps with the same bullet. That's too little differenceto matter muchin my opinion.

The .300 Win mag. was designed to be shorter so it would work in standard length rifle actions. The .300 Weatherby is longer and requires a true magnum length action as a result. Shorter actions are generally lighter and stiffer and are prefered by many for those reasons.

Rifles designed to shoot the .300 Wby have a considerable amount of freebore. Freebore is the portion of the rifle bore right in front of the chamber that is not rifled. All rifles have freebore, it's just that Weatherbys have more in order to reduce pressures. Why is this important to reloaders? Well, some reloaders, myself included,like to seat their bullets out longer than standard factory lengths so that they are almost in contact with the rifling in the bore when they are chambered. This is done to enhance accuracy. With the .300 Win. Mag thisis an option.With the .300 Wby it's not because of the excess freebore(unless you've got a rifle with a custom chamber).

I've owned both and personally I like the .300 Win. mag better.

I agree with Solitary Man. The .300 Weatherby gives a little more power and lot more recoil. I'm completely satisfied with my .300 Win Mag. I just dropped a pig in his tracks at 125 yards last Friday. You can read my story at http://VandenbergWildlife.com.

The .300 Wby. Mag. has more power, and shoots flatter than the .300 Win. Mag. With Norma MRP one can push a 180 gr. bullet 3297 f/s, and a 200 gr. bullet 3150 f/s. I own Weatherby's and the free bore has never been a problem with me. I or my friends have never owned a Weatherby we could not get to shoot under an inch an 100 yards. Between any two I will always choose the one with more preformance. Good luck.

Want to bet you can't get those speeds. I have bet alot on this and never lost.

What ever you are willing to lose.

When my friends and I first got into Weatherby's, we could not reach Weatherby's published ballistics usingpowders available to us. RL-22 gave us the best velocities, but did not reach Weatherby's velocities. We even went as far as purchasing Weatherby Factory Ammo, and took them apart to see if we could identify the power, but we could not. I did some researh and found out Weatherby used Norma components to build their factory rounds. I contacted Norma in Sweden, and asked them forloading data; they sent methe "Norma Loading Data 1995" whichon page (#25) that showed"Norma Weatherby Magnum" loading data. This data was just shy ofWeatherby's ballistics (our velocities were slightly greater than Norma's data using Norma MRP, and matched Weatherby's ballistics). I went to a "Rocky Mountian Elk Foundation" "Elk Camp" in Reno Nevada, and asked the Weatherby folks at their exibition booth if they used Norma MRP, and they looked at me and nodded yes. Now my problem was finding Norma Powders,and justover a year later Graf andSonsreceived their first shippment from Sweden.

If you still want to bet me, fine, but you are going to lose.

Find someone who owns a .300 Wby. Mag. with a standard chamber. Purchase a pound of Norma MRP (contact Black Hills Ammo 605-348-5150 speak to Tery for Norma MRP, or Lock Stock & Barrel 1-800-228-7925 and speak to Robert), Hornady 180 gr. Innerlock bullets, load, andyou will reach 3297 f/s.

Good luck.

I didn't, and I thought you told me you never chonod this before in another thread?

I don't think I have ever built a load with out using a chronograph. When my friend first taught me how to load, he had a chronograph. Irealized how importanta chronograph was, and I purchased one quickly. Good luck.

My appologies, sounds like it would be fun to have a friendly bet.