I just purchased and installed the gun boot mount on my Ace. It fits perfectly. I have a Kolpin Gun Boot 6. I much prefer the Kolpin 6 over the Kolpin 4. It has a clamshell opening and that makes getting your firearm out much easier. I fooled around trying to install mounts on the front cover of the Ace. They cut down on my view of the trail, especially with a tactical shotgun mounted. The gun boot mount has solved the issue of carrying any long gun. I am sure anyone would be perfectly happy with this accessory.