So, the bayonet you guys have modelled is the so called AKM Type II Bayonet.
It's IRL length should be 274 mm, with the blade being 150 mm long. The one you have ingame is quite a bit longer, as you can see on the pic provided, when compared to a real AKM bayonet, seen here. (http://farm7.static.flickr.com/6177/6198168090_66803e4d1c_b.jpg). The pommel of the bayonet should end at the gas block.
Also, it should be able to be mounted on a SVD, see (http://www.dragunov.net/faq.html#bayonet). The SVD you modelled has a bayonet mounting lug compatible with AK series bayonets. One day, if you get the bayonets working together with zombies, it would be a good addition.