300 H&H Magnum

[lastcowboy39]

Hello
I have a 1951 Remington custom in 300 H&H magnum , I would like to know if anyone has taken that case and necked it to a 7mm or if its possable to do ?
I have a 7mm allen magnum a 6mm/06 and a few others but have been toying with the thought if it can be done or not using a 300 H&H casing so any info would be great .

 

[56hawk]

Weatherby did it back in the 1940's to make the 7mm Weatherby Magnum and Remington made the 7mm Remington Magnum in the 1960's. Both are based on the 300 H&H.

 

[Nullcone]

If you kept the 2.85" case length, blew the taper out and the shoulder forward you'd have something indistinguishable from the 7mm STW.

Both the 7mm Rem & Wby mags have a shorter case.

 

[Edarnold]

The .300 H&H Belted Magnum came out in 1925, the first smaller caliber wildcat I can find based on the case was the .280 Dubiel Magnum of 1930, which was just the .300 case necked down to .288. The choice of .280 caliber was probably based on the availability of spitzer bullets in 160gr. and 180gr. weight for the earlier .280 Ross cartridge.
Later, Dubiel also brought out a true 7mm magnum ( .276 Dubiel ), which used the .300 H&H case but shortened to about 2.5" length.

In Europe, the 7x73 Vom Hofe Super Express came out in 1933, similar in case shape to the .300 H&H but dimensionally larger at the base.

So, yes, people have been necking the .300 case down to about 7mm for the last 80 years.