9mm casing flash hole size

[facedown]

I picked up a bunch of range brass the other day, mostly 9mm. I decapped some and noticed that some of the cases have a noticably larger flash hole than normal. They, the odd ones, all have the same oversized hole. They are marked FC NT 9mm Luger.

I'm guessing that with a small charge of fast burning powder, it won't make a difference. But I would think that with a large charge of slow burning powder it might.

Any info or advice?

 

[stans]

Most likely it is brass from non-toxic ammo by Federal. I know Winchester's WinClean ammo has a larger flash hole, but they say it is safe to reload with no changes in powder charge.

 

[facedown]

"I know Winchester's WinClean ammo has a larger flash hole, but they say it is safe to reload with no changes in powder charge."

Thanks stans!