OK, I bought 500 of these bullets a few years ago from Wideners and just "discovered" them in my stash.
Speer 100 grain soft point flat base with cannelure #SE75557
I can't find any info on this bullet. Anybody have any experience with these?

Can't see why not....cup and core 6mm bullet from what I can find

No, they are completely wrong for your purpose. In fact they contain evil lead substances within them. You may want to send them to me and I will see to it that they are properly disposed of, free of charge..

Haha...I knew someone would say that.

Those are exactly the bullet I would prefer if I were using a 243 for deer..

Treat them like any other 6mm 100 grainer and start with a medium load, like starting out with any bullet. I never follow this advice, however, going to a near max load first. Works for me.

I had a buddy now departed whom used just that bullet in his 6mm Remington very satisfactorily on Mule deer.

Thanks for all the replies. I'm glad I got 500.