Just finished installing the tac bolt release from NEIT, and an extended mag release from DLASK on both my 858s...
The Tac Bolt Release went in smooth on the first rifle and functioned flawlessly. I love how I can lock the action open without a mag now.
The second rifle was not so easy... Im not sure if its the rifle or maybe the bolt release itself, but it was helish. The 'pin' was too big to fit in the hole. I sanded, sanded, sanded, sanded, finally gave up and started filing, then sanded, sanded filed etc... Finally got it in there. Then it was sticking on rifle pin that holds it in, so back to filing and sanding...
Anyways, it took a bit of effort, but its in there now and it also functions perfectly.
Overall I am super satisfied with the tac bolt release. It is sweet.