Now, I don't know if this is something that everyone knows or not, because I did some searching and I didn't come up with anything actually related to animating weapons while they are held (Nor did I see animated weapons with working animations when held tbh), so here we go.
While making a new MDC weapon today I somehow (For unknown reason) figured out a way to animate weapons while they are held (Or not) without lua and/or whatever other ways there are (Seeing as SpriteAnimMode = 1 on held weapons doesn't work and all) - The trick is to use attachments to do the animation (Without them interfering with the weapon's default animation (Weapon000, Weapon001, etc.).
I was going to make a detailed tutorial on how to do this, but then I realized it is simpler for whoever needs this to just look at the thing and figure it out in 30 seconds then for me to spend an hour writing a goddamn tutorial.
I am attaching a weapon that has 3 different animations running so you can check the extremely simple method and use it for your own guns/tools/nades/other held devices.
Here are some gifs of how it works (The thing is supersized for 'ease of view', why? I don't know, I just felt like making it huge.)
Turning left/right does not displace animation.
Notes:
Frame rates even out (It takes about the same time for a 3 frame animation and a 10 frame animation to complete a cycle) - You can see it in the gifs.
And uhhh.... If the weapon is destroyed there might be animations flying around until they settle... >_______>'
Here is the .rte
Attachment:
PS. This probably works on magazines too (If mags can have attachables that is), but I didn't check, so feel free.