T-Pull for Kronos with no need to drill any holes. Friction fits between the two halves of the slide. Note you will need to remove the priming indicator and de-priming switch to fit it in. You also have to remove the two bottom covers because it replaces that spot and fits into there.

I've used this with a NFStrike 14kg Longshot spring with no breaking as long as it's printed with a good infill of at least 75%. Lower might work, but it could also break so I would not recommend.

Make sure to use supports.