[john humphries]

The 4 groove barrels were made from the original 1903 until 1942-43 and the two were mixed during those years. I have a 1903 Remington (Modified) made in 1943 for the Marine Corps with a 2 groove Sedgely Barrel marked USMC and a 1903 A-3 Remington with a 4 groove Barrel also made in 1943. Strangely Both are dated 9-43 on the barrel. Remember that both would be used as replacement barrels until stocks ran out.The 2 groove Sedgley is the more accurate of the two and that may be that the 1903 is more accurate than the 1903 A-3.:usa:

 

[john humphries]

The barrels sound like most I have seen, The barrel on my 1903 A-3 is very rough under the hand guard as if it was turned and left unfinished as a way to speed up production. The 1903 however is as nice as any I have seen in the finish dept. and that is the way most Sedgely barrels are that I have seen. The color is / was determined by solution strength and temprature. Also alloy of metal affected the color.

 

[john humphries]

My 1903

 

[john humphries]

A technical reason is that at the time they were using these there was several reasons. First was ease of building them and reduced tooling costs. The second reason was ease of cleaning for the troops as any one who has cleaned Marlins micro-groove barrels will know and most important they were more accurate with the ammo produced during the war.

 

[john humphries]

the 4 groove barrels were harder to make quickly at the time than the 2 groove because tooling had to be built and 4 groove rifling bottons took more time than 2 groove rifling bottons to cut.