While waiting on my new slide stop spring (I was out of town all week till yesterday), I checked the M380 with Remington 94gr FMJ (round nose) and it seemed to work fine..... no issues with the slide stop hitting the second round in the magazine. I tried the 100gr FM ammo I had just bought and the second round was actually moving the slide stop up very slightly. Moving the slide back far enough to where I could lock it open, then moving the slide stop lever, I could feel resistance at the lower end of the movement range.
With a magazine removed and slide held open to the point where the slide stop could engage, when I moved the slide stop up and down, it felt spongy soft, like it had insufficient tension on it and would not totally seat in the down/unlocked position.
Got home yesterday and the new spring was waiting so I was eager to install it and see what differences would result. Its a bit of a booger to get the old one out, but fortunatly I had gotten a set of piks and precision tweezers that were a tremendous help. Removed the old spring but also noticed the position in the groove looked suspect. On the spring, the end that slides into the hole to secure it in place has a flat notched spot on it. The hole also has a squared edge at the bottom. When I first started, I tried installing in the same position it came out, but could not get it to go in. Backed off, looked at it closer with my jewelers magnifying glass with light and could see where the flat spot on the spring had to be positioned to line up with the squared edge of the hole. Basically the straight end that seats in the slide stop will be pointing at around the 4 oclock position. I placed some tape on the gun in that area to prevent a scratch when I needed to roll in into the groove. Needed at least one more hand
but finally got the spring slipped into position. It definitely had more tension on it. Put the slide stop back on and it would snap back in unlocked position as I had hoped (like my M9 & Mustang). Placed the slide back on and tried again with slide locked open, put a loaded mag with Remington fmj and pulled the slide back and slide stop snapped back in unlocked position with a noticeable "snap"..... Yowza !!
Headed to range later today to see how it does.