It was just this short in Payday, Since I have a picture overlay I use for reference sheet.
I mean, you can go ahead and try out this new style, but the way it looks in-game is really important. Most blockland models are wildly disproportionate to the player model, usually being way too big or having exhaggerated features. This is the standard 'style' of blocko models. If you don't follow the style correctly, you might end up having the model be too small for the player. The easiest fix for this (imo) is to take the entire darn slide and scale it vertically 1.5x bigger than it already is, as well as 'shorten/compact' the front part of the gun. Trust me, if you want to nail the style on point, you can't just follow the book and make it proportional to the reference drawing. You HAVE to make stocks shorter, slides larger, etc.
Otherwise, if you're following your own style, go for it. The guns still look great even without the tweak!