The kit provided guns are overscale, and inaccurate in shape and style.
I replaced mine with brass 32mm length guns from RB Models (Poland) but since then resin versions have come onto the market. Vanguard sell six pounder gun sets which you may wish to consider, and I believe Chuck (Syren) also supply resin barrels.
While you're at it you may wish to consider the swivels. The Amati supplied versions are awful, I again used brass versions 15mm from RB models which are spot on for scale. These do involve making your own crutches.
The Amati gun carriages just about pass muster, but the trucks looked very thin and I also replaced those.
If you click on the gallery pictures across the top of the page to enlarge it, you won't have the scroll function.
You need to click on the build title at the top left of the photo; this brings up all the photo's in the set, enlarge the first one and the scroll arrows will appear.