400 Whelen advice

[John J]

I picked up this rifle the other day. Remington model 1903, SN says it was made 1942. Should be way above the range of the bad heat treating situation. I have 400 Whelen basic brass on the way. The gunsmith that built the rifle cannot recall the job. I have been researching all I can. Based off what I have found so far I need to find out my chamber spec. Rifle appears to be barely used but has sat for a while according to the gun shop. According to my findings I need to fire form a case and try to accurately measure the shoulder for a diameter of .458. I do want the proper Griffin and Howe/ Petrov spec and will correct if need be. With the lack of dies and chamber spec, I have read 41 cal pistol die (neck size till case chambers) and 41 cal bullet should get me the info I need. Right now I can get Hornady 300 gr .411 diameter (405 Win bullet) jacketed or .40 cal (.400) cast, can't remember the weight, 180 gr? Any info, advice or a reputable smith familiar with this cartridge is appreciated, John

 

[sestoppelman]

ANY Remington '03 or A3 is safe and not affected by the early heat treat issues which only involved early Springfields and Rock Island actions.
Thats a pretty neat looking rifle though, though cant help you much on that caliber. Making a chamber cast might be a good idea though.

 

[John J]

ANY Remington '03 or A3 is safe and not affected by the early heat treat issues which only involved early Springfields and Rock Island actions.
Thats a pretty neat looking rifle though, though cant help you much on that caliber. Making a chamber cast might be a good idea though.

Good to know thank you. The GS wasn't receptive to a chamber cast when I brought it up.

 

[sestoppelman]

Could have someone else do it. Be nice to know if its an improved chamber for the sharper shoulder for better headspace control.