Mammut smart alpine indenting a carabiner

I've been using a mammut smart alpine as my primary belay and rappel device for years and I noticed recently that the carabiner I use to belay with it got indented on top right where one of the metal parts of the smart sit. I don't know how or why that happened, but I'm wondering if anyone else has had that happen. Is it because of the shape of the carabiner I'm using maybe?

Edit: photos uploaded

?

aikibujin wrote: Similar to the scratch produced by a Mega Jul?

 It's hard to tell from that picture, but I think that's a different kind of issue. Mine is more like a 1-2 mm indentation rather than a scratch. 

My mammut smart wears my hms biner in the same spot/pattern, but not so dramatic an indent. I imagine it will eventually get there, but not overnight.

yep. grigri does it too. actually worse because the grigri makes burrs on the inside rope bearing surface of the biner. fortunately, when using the grigri the rope doesn't touch that biner, buuuuuuuut...

i prefer to use less specialized devices that don't leave me with a carabiner on my rack that I have to remember to inspect for burrs in an emergency faff where I need "just one more locker, dammit!" I still use a grigri where warranted, but gave up on the alpine smart. First off its freaking huge, maybe not weighty but quite bulky, it needs a nonstandard weirdo anti-crossload carabiner, which entails a funny shape or a big plastic crossbar, and only works with some rope sizes. i went out recently with a bunch of folks who used smarts (you know who you are!), but, surprise, they were too low-friction to catch falls on the narrow half ropes and we had to pass around a single belay device which can entail a lot of additional faff when you forget to take it up the pitch with you because its never not on your rack except for this one time and your partner is using it. Also, on newer ropes even of the appropriate diameter, I often found the rope would much more easily slip, sometimes quite quickly, due to the long smooth rope channel when holding body weight. And if it jumps the channel it can move 4" to the side which could make you lose control of the brake strand if your grip's not tight enough, which kind of negates the advantage of the brake-assist.

anyway so that's my alpine smart rant. I'll be here all week folks

My Jul 2 is doing the same thing to an aluminium dmm biner. If you are worried, I would suggest swapping the aluminum biner for a steel belay biner to reduce the risk of burs in the metal. 

Mine isn't doing that, but then again, the Smart is so clunky that I never use it.  

Jay J wrote: Mine isn't doing that, but then again, the Smart is so clunky that I never use it.  

I use mine all the time and I love it. I'm not sure if it happened suddenly or if it's been happening gradually and I just now noticed. 

any dedicated belay/rappel carabiner is going to suffer wear/damage in normal use.  I've solved the issue by switching to a steel locking carabiner for belay/rappel.  no visible wear or damage after ten+ years.

My original Smart does this too. I don't use it often but when I do it is always with the same 'biner and I replace it whenever I start to get nervous about the notch.