I was dismayed to find that there were no big, beefy, non-automatic guns in the game. The anti-materiel rifle just isn't beefy enough for me and I don't like how quickly the minigun eats ammo. My solution was to make a single-shot, non-explosive version of the grenade machine gun, since it looks like a cannon anyway.

I have the functionality down and I don't think it'll be terribly unbalancing, though I will need to learn a little more to get the ammo availability right. Right now I'm trying to get the look and feel down.

I want it to be semi-automatic but the animation doesn't seem to support that. If I uncheck automatic the animation plays very quickly but it doesn't actually fire. If I have to make it automatic I'd prefer to get the firing rate down to something like one shot per second (with an 8-round magazine). However the animation seems to play the same no matter how it fires, animating recoil for a much faster rate of fire. Anyone know how to either get it to work as a semi-automatic or somehow get a delay in the animation so it looks right? Right now it'll fire immediately if I click the fire button but if I hold it it'll pump ineptly for a full second before firing the first shot.

Secondly, I want it to look and sound like the world is ending. Anyone know a weapon with a nice big muzzle flash I could use, and any recommendations for firing sounds? I tried using one of the biggest weapons in the game as the firing sound but it had a slight delay on it so no dice. Worse to worst I'll learn how to import my own sounds I guess.

I can post a link to a copy of my .esp if anyone wants to take a look. Sorry if these questions are either contemptibly obvious or totally impossible.

Change the attack animation. You've untoggled auto but it's still using an auto attack anim (AttackSpin or AttackLoop).
You may want to look in the BSAs to see what attack anims are available for that weapon grip.

Thanks for the help, Toaster. It seems that the weapon doesn't have any "single shot" animations but it does have an "AttackLeft" animation which looks like a whole lot of nothing special. My gun doesn't animate the recoil dampener dealie when it fires but it looks just fine if you assume it's a static barrel.