Exactly what I was referring to. Those dimensional charts give the min & max specifications that factory ammunition manufacturers need to follow in order for their ammo to fit safely in every "factory" firearm made in any particular caliber. Those same dimensions also give reloaders a baseline to go by. However, just because one type of ammo is longer or shorter than another doesn't mean they are out of spec from SAMMI. It only means the manufacturer choose to seat the bullet where they put it based on best over all performance and bullet profile however still within spec.

But you already knew this!

Please don't take this the wrong way kerrdog,

To me, when anyone ask this type of question my first thought is they need to read a reloading manual and visit the SAMMI site. No the site doesn't take you by the hand and specifically talk about why different manufacturer ammo are different lengths nor do they have a FAQ link and maybe they should. But by the same token, one should be able to figure it out without too much difficulty. If you know the specs, take a micrometer, and measure the ammo, one should be able to draw their own conclusion rather easily. If not....well you know where I'm going with this. I realize this was just a innocent question but it was the type of question that leaves me wondering if a reloading manual was ever read. Every reloader should read at least one. kerrdog, if you have read one or two manuals than please foregive me for sounding like an a$$ and I meant no disrespect. I just felt you should have known this from the get go. I apologize.