I’ts quite hard to see the details on your pistol but I can tell you that 32,000 tris is way too much for that model, that’s the tri count I would expect to see on the average assault rifle.
you should try reducing the tri count as much as possible before thinking about making LOD’s for it, also how many UV’s does it have because you should be able to just use one for each separate mesh which would usually be one for the main body of the gun and another for the mag(maybe an additional one for the sight/scope if its changeable).