Update on load development, backed off one grain of powder and 10" increased to 553 and 20 was 316 in 20". Backed off one more grain just to see if the increase in 10" was a fluke and shot the best 10" count we have seen so far 617 in 10" and 308 in 20". They were shot out of my modified BPS with 21" barrel and Comp n Choke XXXFull at a laser ranged 40 yards.
My buddies SP10 prefers 2 more grains of powder and is pretty consistent with mid 500 in 10" and 350+ in 20". His H+R single shot has an issue with piercing primers with our loads but it also does with Apex loadings.
Unsure what the cost is as I have not broke price down yet but I am buying TSS for about 40 bucks a pound and we have a shot trap also. I load for several people from 410, 16, 20, 12 and 10 gauges.
We were pretty content with the Apex loads for the 10's but they have increased to over 70 bucks and really didn't show a big increase over their 12ga 3.5" 2.5oz loading. We decided that if we were going to pack a 10 that we would have to see an increase in performance so we finally found all the components we needed and started loading them.
Ridge Rooster