I just got in a set of Talley LW lows for a T3 300WM. I just miked the factory rings a .473 and the LW lows miked .507. I didn't realize they would be taller since they are "Low" and I'm glad I went with the lows instead of the med. I thought the factory rings were a touch high with the VXIII 4.5-14x40, oh well, they seemed to fit fine.
I went with Burris DDs and med rings on my t3 338fed and they are a good bit higher than the factory tikka rings, but still feel fine as well. I wish the factory rings were better. They would probably hold fine, but they just look cheap to me. The 300WM has alittle buck to it, so I definitely wanted descent rings. The Talleys look like they will work well. These are only my 2nd set of Talleys, the first were steel rings and bases on a Sako 75.
Have a good one,
loder