I bought some 123 SSTs for the 6.5 Grendel. Was that bullet optimized for the Grendel velocities or is it tough enough to use in the 260 and Creedmore for hogs and deer?

That one I think was made for the Grendel. It does expand well at Grendel velocities and often exits

Too much velocity for that bullet in my opinion. Bad medicine on coyotes though. I’d load it and consider it a varmint only round.

I don't mind a bullet ripping to pieces as is goes through an animal but it has to have enough weight and sectional density to make it through to the off side hide. In this instance I am pretty sure you are good to go for loading in a 260 but I would pick a heavier 140gr if I was going to shoot something over about 150lbs.

In my 260 I normally hunt with 120 gr Nosler BTs, and sometimes the 100 gr Nosler BT. In a 20” barrel, the 140’s are a bit slow for my taste. I had plans to use the 100 gr BTs in the 6.5 Grendel, but I’d like to get a couple hundred more. Wish me luck on that. The grandson’s Grendel is set to shoot Hornady factory 123 SSTs, and right now my Grendel is set for 95 gr V-Max reloads, and I intend to try a CNS shot on a pig with that bullet. I did acquire a couple hundred Hornady 123 gr SSTs for Grendel use and wondered how they’d do on pigs using the 260. I figured they were softer for use in the Grendel, but didn’t know that for sure. It isn’t really that I need to use them in the 260. I just wondered.