GBA,
8-10" was an estimate as I saw thru bino's at 100 yards, later found 15" of nock end brock off as he slipped sidehilling on a slab of rock (had blood on broke end but may have just ran down arrow shaft or sprayed as you have said), never found front end don't believe it came out in the 5 miles we trailed (maybe didn't come out at all as the blades lock once deployed). This leaves 14" plus tip, I do not believe all of this penetrated from what I saw and how the deer reacted. I do not claim to be an archery expert and can only go by personal experiences in the field, as well as the advice of peers and local experts. Sorting thru every experts recommendations, such as yours, is tough. I did use a heavier arrow along with a grim reaper when I killed my bull elk , blew thru ribs entry and exit complete pass thru, broke one blade off on entry rib. You maybe right, 23 more grains of weight would have resulted in a recovered animal along with better shot placement without a doubt. Montec on the arrow, closer shot, fraction of inch I moved as my brain went through the shot from level to pin to pull thru on the extreme sidehill shot (getting level was extremely difficult and didn't feel natural on a slope that was difficult to stand on) no doubt would have had a different result. Yeah, I f'd up, I'm not proud but I felt I should pass on my experience to hopefully help other hunters learn from a real world no BS experience, knowing I'd get ridiculed.
I was not bagging on mechanicals just saying I will be using fixed from now on unless it's a very long follow up shot on a hit animal or I have to shoot someone's dog before it climbs up a tree to eat me.
If you've seen Randy Ulmers NV buck from this year you've seen theres no blood on the entire right side of his body, photoshop-nah, lack of penetration probably, poor shot placement-possible but not probable, did he use his new ulmer edge-one would hope so, was the shot over 70 yards like most all his kills,elk included-probably, or maybe it simply was not a heavy enough arrow-due to his lack of knowledge.
Spear