Sierra Heavy TMK 6MM Testing

Just for reference, a 77gr. I had cut open a few months ago for some government work.
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That is an awesome job, I cant even slice a tomato that fine.
 
Appreciate the report Carl.

I had pretty much dismissed the 115-ish grain offering due to the only 6mm I have twisted faster than 1 in 8 is a 6 ARC.

Looks like they will work in a 1 in 8 at my elevation, if not optimized. I may get in line for a box. I can't see the added mass being a bad thing for a killing bullet.
 
I added these bullets to my spreadsheet, backed out a g7 BC from Form's trued numbers, and ranked by g7 form factor i7.
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I tend to look more at form factor than outright BC when I'm choosing a bullet, since it's a measure of "BC per bullet weight" (you'll see it tracks the BC/gr ranking) and should give you the bullet with the best overall trajectory, factoring in recoil, MV, and wind.

These new prototypes are definitely on the upper end of performance in this regard, which is nice to see from Sierra since some of their bullets are absolute duds.

If you rank by i1, they look even more competitive:
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But, I try to focus more on g7/i7 since it's a better drag model for the modern bullets we use.
 
My common thoughts was a lighter than lead plastic tip would aid in stability from a lil slower twist, but my understanding may be backwards. The longer the bullet, and further rearward the center of gravity(due to plastic tip), the faster twist it needs, so sources have said.
 
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