NicgidSling Ruckscke, Sling Brusttaschen Schulter Bauchtasche Crossbody Taschen fr Mnner Frauen Outdoor Reisen

Q: Could this bag fit brass gun cleaning rods 12 inches in length?

In length is ok...Ok...! but. I don't know the size for your brass gun..

Q: Is this bag big enough for a 70-200 camera lens?

It should fit, I use mine for my 10 inch tablet + bluetooth speaker.

Q: Is the strap reversible?

No. The strap is not reversible.

Q: Can it fit a standard size plastic water bottle?

It will only fit a standard size water bottle 16.9 oz up to about two thirds of the bottle's height. And that is only if something in the bag is not protruding into the water bottle pocket. It also just off to the side and is very noticeable. If you are walking leisurely it doesn't bug you as much, but if you are a fast paced walker or expect to use the bag as intended as a quick bag, it doesn't work so much. For the most part I've had to put the water bottle in the main pocket if I want to bring one. Hope this helps.