Sanity took another dip today......
One side of the gun is done:
And we come to the first glitch!! Looking at the build diagram and the areas circled in red:
Firstly there are two parts labelled 30 on the sprue diagram!!!

Secondly the positioning instructions for part 30 are, frankly, diabolically awful!!
Also the part labelled 36 is actually part number 136.
Anyone with this in their stash might want to make a note of this.
Next issue is the amount of flash on the minute parts.
There are quite a few of these that are going to need very careful cleaning
Lastly for step 5 two parts are short shot - the parts are laid on the diagram and its obvious where - incredibly annoying as it made getting this sub assembly to line up a nightmare.
Hopefully its right. So - close of play today we have half the gun complete, breech in progress (the moulding left the joins with rounded edges so I've had to resort to filler!! And the sliding block had a massive sink spot - also filled. The mantlet is also complete together with the frames in steps 4 & 5.
