Hi All
Just installed a new optics cut SIG slide on my P320 X Compact. Haven't fired it yet, but noticed that the slide will not go all the way forward if I ease it closed. I can push it closed. However, if I rack the slide or use the slide release, it is fine. This slide did not come with a recoil spring or barrel. Any thoughts?

The barrel may be a tight fit due to tolerance differences. I have seen something similar with Classic line SIG pistols, and usually just firing the gun will wear it in enough to eliminate the hesitation.

Never "ease" a slide forward. Let the slide go and the spring do its job. Not designed to be eased forward. This will cause a malfunction.

^^^ Yup. This is something that needs to be drilled into every gun owner's head. When the gun is in real operation, the slide moves back and forth with violent forces. Easing the slide in resulting in it not going into full battery, or gently racking the slide back resulting in round not properly ejected, is not a measure of anything meaningful regarding the gun's proper operations.

As an aside, there is a theory on ‘no shoot-break-ins’ of sorts. Just as you would imagine, new gun, empty, magazine out, some lube, then rack the slide a BUNCH. Of course we like to shoot, buts it’s a little something one can do before we get to the range. I think it was more popular when ammo was in short supply.

Eventually nothing can take the place of shooting then testing real ammo.