Various grades were offered. Standard, Custom, etc..
The frequency is 300/30 = 10 Hz The time period is 30/300 = 0.10 seconds
300 / 25, or 12/1.
300 BC
$300
PN 20 is equal to ANSI 150 & ANSI 300 equals PN 50.
There was no 300 Winchester Magnum cartridge in 1939. A 1939 Model 70 would be marked "300 Mag"...and it will be chambered for the 300 H&H Magnum cartridge. There was no other 30 Magnum cartridge in 1939 in the Model 70. The 300 Winchester magnum cartridge was introduced in 1963,...the last year the Pre'64 Model 70 was made. Your 1939 Model 70 may have had a later barrel swapped in to it. 300 Winchester and 300 Win Mag are the same cartridge.
The 300 Winchester Magnum was not introduced until 1963. So yes most likely it is the H&H. I would do a chamber cast to make sure though. Both the .300 Win Magnum and the .300 H&H Magnum were standard calibers for the Model 70 in that era, with the .300 Win Magnum the more rare of the two. If your rifle is only stamped ".300 Magnum" it is more likely the .300 Win Magnum. You will want to have the chamber cast and the caliber verified before attempting to fire the rifle. I am lucky enough to own a pre 64 model 70 win,in the 300h&h.It is stamped 300 H&h Maginum.If your gun is stamped 300 Magnum , it is probally a 300 win mag.
100-300
The 300 Win Mag wasn't introduced until 1963. It could have had a new barrel put on it. Take it to a gunsmith.
100-600
50-550 usd
100-300 USD
NOTHING............Its a Remington
100-300 USD
300-500
100-300 dollars
100-300 USD or so