First of all let me be very clear, I am not a Sig kinda girl. CZ is my poison and I drink the Koolaid with a vengeance. Each and every CZ I own has worked flawlessly right out of the box, never a single issue with “breaking in” the gun. Take it out to the range, load the mags with ammo, shoot, reload, repeat and go home. Each and every CZ without fail. This is the first time I bought a Sig, I bought a 9mm P320 X5 and decided right off the bat that I was going to shoot IDPA Carry Optics with it and Carry Optics only as I have a CZ P-09 for SSP. I have a CZ Shadow 2 for Production IPSC and have another OR CZ Shadow 2 coming for Production Optics, but sadly they are too heavy for IDPA, alas otherwise I’d just be shooting Shadow 2s. I was initially going to get a CZ P-10C Optic Ready but I like the bigger full size pistols and was talked into buying the X5 instead. I’m not a huge fan of striker fired pistols either, but I figured o.k. I’ll break from the norm and buy a Sig and a striker fired pistol. So, I got the Sig. When it arrived, it got stripped down, I cleaned the shipping grease off the guts, cleaned and lubed the barrel and lightly regreased everything that needed lubing. Took off the rear sight plate in preparation for the optic and reassembled the gun. Spent the last couple days dry firing and getting used to the very different slide assembly from a CZ, with the Sig slide riding on the outside and being careful to keep my shorter than average thumbs away from the slide release, I have a hard time reaching the slide release at the best of times and usually have to do it by removing my non dominant hand off the grip. Today the Romeo Optic arrived and I put it on the Sig this afternoon. Everything seemed to be working fine with dry firing, etc. Took it to the range and started working on zeroing the optic, right away decided the front sight needs to go and it’s coming off today, but I noticed that each time I emptied the mag, the slide does not lock open after the last round. I’m shooting 124gr Campro Bullets with 4.0gr Vihtavuori N320 for a power factor of 131, velocity of 1056 approx. My initial thought was that the recoil spring needs to be heavier, but I’m not sure. The gun was never fired without the Optic in place because my registration certificate for the gun didn’t arrive until today as well. So I’m not sure if the Optic is throwing off the gun’s Chi. Or it just needs to be fed a pile more ammo and broken in. I’m also going to try some of my heavier 147gn match ammo. Anyways, the trigger is really nice and I love shooting the Optic, so either way I’m going to make it work. Just wondering if anyone else has any recommendations for the problem. Will be disassembling and greasing up the mags too as someone had suggested on another thread.