This is a problem that has been around since the first DH book, it has been repeated in every 40K RPG. It's minor but consistent.

Under the entries for Semi-Auto Burst and Full-Auto Burst (pg178 + pg181) "The number of extra hits scored in this manner cannot exceed the weapon’s full/semi automatic rate of fire". That means the maximum total number of hits are the rate of fire + 1. However all weapons are set up with semi/full-auto rate of fires that are fractions of their full clip size. This seems like a mistake. It also makes it easy for players to miscalculate the ammo expended with each action.

For example:

Autogun, Basic, 100m S/3/10, 1d10+3 I, pen 0, clip 30, reload Full

This weapon can only be fire twice on full auto, expending 11 rounds per turn, a total of 22, leaving 8 rounds in the clip. The clip size of 30 looks like it expects the player should be able to fire 3 times. Players would often just strike off the RoF number of rounds (in this case 10) when they should expend 11.

Another, thing that I would like to see clarified in the book is what happens if you want to fire full auto or semi-auto when you do not have enough bullets. We all generally just say it's not allowed, but it would be nice to see this written down somewhere.

I think it would be easier to just change the language to:
"The number of hits scored in this manner cannot exceed the weapon’s full/semi automatic rate of fire".

I think you might be wrong about an autogun firing 11 rounds on full auto. In DH1, Rate of Fire is defined as "the number listed describes the shots fired", so you would be able to fire 3 full full-auto bursts.

However, the wording of the rule does seem to indicate the extra hits cannot exceed the rate of fire, giving a maximum of 11 hits (let's assume this was possible) in the case of the autogun. That seems to be the oversight.

As for firing full-auto without a full X bullets, in my game I've always ruled that if the clip has more rounds than the semi-auto value but less than the full-auto value you can fire full-auto as though the full-auto number was however many bullets you have to lower the max number of hits. I have no idea whether this has been addressed officially anywhere.

The autogun only fires 10 bullets per Full-Auto Burst, so in this case the burst value is a multiple of the magazine size. However, this is not true in all cases: for instance, the heavy stubber can only fire 8-round bursts but has a magazine size of 75... What??? It should just hold 80 rounds!

I guess if you have fewer bullets in the clip than the RoF of the weapon then the number of maximum hits simply drop to the number of remaining rounds.

The autogun only fires 10 bullets per Full-Auto Burst, so in this case the burst value is a multiple of the magazine size. However, this is not true in all cases: for instance, the heavy stubber can only fire 8-round bursts but has a magazine size of 75... What??? It should just hold 80 rounds!

This was pointed out in the OW beta, and corrected for the version of the chimera but not the main weapons table IIRC.

Which should serve as a warning for how closely our suggestions will be read.

I guess if you have fewer bullets in the clip than the RoF of the weapon then the number of maximum hits simply drop to the number of remaining rounds.

Now that the modifiers give you an advantage for firing single shot over semi-auto and semi-auto over full-auto, this kind of makes sense. However, it falls apart when when firing suppressing fire...

We all have different house rules for it, that's why I was saying it would be good to get a rule into the book.

Heh, we have always played with that if you do not have enough bullets left in your gun to do said auto or semi, than you can not do it. Either start reloading or do some single shots.