I took my new Rock Island Tac II full size 10mm to the range today. First the good. I also took my SIG p220 10mm ( 2nd range trip with it) and I shot a bit better with the RI than the SIG. Now the bad. Function with the SIG was 100% but I had problems with the RI. The slide locked back after the third round every time and once after the fourth round. This is starting with a full 8 rounds in the mags. I used 5 mags, the one factory (Metalform?), 2 Metalforms and 2 MecGars. It did this with all 5 mags. Is this something that will work itself out or is an easy fix? I also had one misfeed. Ammo was my hand load of 180gr FMJ FP over a relatively light load of Longshot at 8.7gr and an AOL of 1.250". At first I didn't think I would like the grips because they seemed very abrasive but I didn't even notice them while shooting. If I can get the one issue fixed I think I will be happy with the Rock Island. I have a flat bottom firing pin stop and new springs to install. I wanted to shoot it stock the first time to see how it functioned.
It may be the issue I had with my ms with the side of the mag pressing against the slide stop especially if you use your support hand underneath the base of the mag. You can remove the slide put the slide stop back in and put in a loaded mag and see if it effects the slide stop.
Any chance you can have a shooting buddy or a range buddy shoot it and see if it does the same thing?
I'm having the same exact problem with my RIA 10mm (4.25). The slide was locking back after the 3rd round with 3 different mags. The only thing I could think of was maybe the slide stop was moving up on its own or I was moving it with my offhand thumb under recoil. It's weird that it only happens after 3rd round though. I replaced the slide stop with a lower profile Nighthawk custom slide stop. It dropped right in. I haven't had a chance to shoot yet but I will report back when I do.
Wow, I have the Tac II and it's only problem was it did not like just one of my third party mags. All other mags worked just fine.
Quote from: shadowsk on June 12 2015 12:16:11 AM MDT
I'm having the same exact problem with my RIA 10mm (4.25). The slide was locking back after the 3rd round with 3 different mags. The only thing I could think of was maybe the slide stop was moving up on its own or I was moving it with my offhand thumb under recoil. It's weird that it only happens after 3rd round though. I replaced the slide stop with a lower profile Nighthawk custom slide stop. It dropped right in. I haven't had a chance to shoot yet but I will report back when I do.
Let us know if that fixed it for you. I took the slide off mine and watched as I inserted a magazine. It seems the mags are just barely making contact with the slide stop. It may be enough that it doesn't take much to raise it up from there.
Be sure you are not bumping the slide stop under recoil to have it engage. With your slide off and the slide stop installed you can watch its movement with a magazine in place and also look at the ammunition profile to see if the ammo is part of the problem...
Early on in the development stage of the S&W 3rd gen guns it was found that they too experienced slide lock open. When the reviewed the operation with slow motion playback the found the slide stop was bouncing upward under recoil and engaging.
The fixed this by making the slide notch slightly different.
UPDATE: I went out again today with the RI. The only things I had done to it since the first range session were to install a flat bottom firing pin stop and some very minimal dremel work on the slide stop. With the factory and metalform mags things
were worse. The slide would lock back 2 or 3 times per mag. I had also bought some Wilson mags, 47nx, so I tried them. Function with the Wilson mags was 100%! Not a single malfunction using these mags. I guess I will have to buy a bunch more
of them. I am surprised at how well I am shooting this gun. I am doing much better with it than my new SIG P220 10mm.
Mags make a huge difference in a 1911.
I purchased one of the Tripp 10 round mags for my RIA and it fed everything I loaded it with. Pretty pleased with the mag.