One might argue that a good sight picture can be obtained with the 1903 Springfield front sight protector in place, however, it is an argument with little merit. There are two problems with the sight picture when using the 1903 protector.
1. In most cases, depending on the sight blade height, the top of the blade is not centered within the upper portion of the protector which makes the sight picture confusing with the 1903 rear sight, and unreliable with the 1903A3 peep sight.
2. Since the protector is not fixed to the front sight it moves side to side which makes it near impossible to acquire a repeatable sight picture. And, some model were not entirely symmetrical which caused them to cant when attached to the sight base.
In a previous statement the writer argues "Every battle rifle I own or have used which was built from WWI to the present day has front sight protectors. Most are permanently affixed, some can be removed easily, some with great difficulty, some with a few minor tools. All are designed to see the sight through them whether they are permanent or not."
Most of the rifles mentioned have fixed sight protectors which are ears, and do not surround the sight blade. The SwedishMauser has a removable front sight protector, however it is more firmly attached than the '03 sight protector, and it is larger in diameter so that it doesn't interfere with the sight picture.
Another issue with the '03 sight protector is that some models were oval in the area surrounding the sight blade, especially model built by some WWII contractors.
Here's a comparison of sight protectors:
- 1903 Springfield 3/8" inner diameter
- USMC 1903 Springfield 4/8" inner diameter
- Swedish Mauser slightly larger than 5/8" inner diameter