Just that in your experience how big a steel shot do you have to use to equal the performance of lead 7 1/2 shot..mb

Steel size 6, 6.5, or 7 depending on the alloy. I've seen fairly significant differences in pellet weight between manufacturers and even lot numbers. I've had better results with #6 steel on birds like quail as they tended to be further out and going away but #7 steel worked fine on woodcock, rails, and snipe.
For targets I use #6 in place of 7 1/2 if allowed, #7 for everything else.

Thanks woods, in the past I've used the federal 1 oz of steel 7's load just haven't shot enough of them to have a definite experienced opinion about it.mb

Edit to add it's use will be for doves in non tox areas

I think the old rule of thumb was, that you dropped 2 sizes in shot size going from lead to steel. So in other words, lead #8 would equal steel #6 (which goes along with what woodmaster81 said)

That rule of thumb was for lead shot sizes #6 and larger. As the lead shot size gets smaller, the weight differences become less. For lead #8, size seven steel may be lighter or heavier depending on the actual alloy. This is particularly true when comparing high antimony lead shot to a heavier alloy steel shot.

In BB steel, I have seen as much as a 5 pellet discrepancy in a weighed payload between different bags of shot whether different manufacturers or same but different lot. That inconsistency is one of the reasons I stopped loading steel.

Good to know. I know when I was shooting lead at ducks, I liked #5 shot. After the switch to steel, I dropped to #3 and eventually down to #2 steel. I was working at a sporting goods store as a part time job, I remember Federal came in and held a small class on steel shot for us. Their take on it was that speed kills, and I think that still holds true as you see more and more companies loading faster shells.