actually ALL (100%) of the commercial 30.06 ammo I have tried in my Garands of over the years (I would guess about 10+ types of foreign and domestic ammo) seemed to shoot and function fine with normal ejection and nothing violent or strange. In fact, there is some commercial stuff that is absolutely SUPER.

In this category is Remigton Green Box and the South African stuff (Igman)d 150 grain soft point) Federal GMM etc.

Since you started to shoot the M1icon just like HUNDREDS OF THOUSANDS of other owners who had never heard of this ammo/pressure issue and proceeded to shoot MILLIONS of rounds of the "wrong" ammo, don't worry about it too much. I think the better option is buy ONE box of anything you like. If the stuff doesn't sling out brass 40 feet and/or doesn't seem to lead to violent op-rod movement, shoot the rest and buy more if you like.

an additional caveat MIGHT be that you should likely stick to lighter bullet weights (150 grains).