I believe that the game has been out long enough for us all to acknowledge the presence of an upward trend in the number of people running around with auto-shotguns holding frag ammo, and I would like the community's thoughts on this. I'm not the type of fellow to complain about balancing issues, but I've noticed that the effectiveness of this arrangement seems to verge on the absurd.

Am I completely wide of the mark on this, or is this something that should be addressed?

If I am not mistaken DICE already toned down the damage of the Frag ammunition in the USAS-12. Personally I like auto shotguns, but with the regular buckshot.

I think it's pretty absurd. I was playing last night and there was someone on the other team who only used the Frag rounds. It gets pretty irritating after a while.

I only use the pump action shotgun on principle, with no frag ammo.

They're fine. High delay after firing. Slow flying projectile. High deviation. Extreme Bulletdrop. No onehit-kills.
 
They are effective on tight CQB maps with lots of static and entrenched combat, and even there they are easily outgunned. TTK is rather high, especially since the last nerf. If two dudes stand facing each other, both holding down the trigger, usually the dude with the frag ammo dies. Add sidestrafing hipfire to the mix (as CQB is done), Frag Ammo just ain't competitve. It's great for static fights. For killing campers and softening-up entrenched opposition. In a dynamic firefight, which is pretty much all the time on B2K maps, frag ammo shotguns just don't do so well, regardless if it's a fullauto shotgun or not.
 
For in your face CQB, Buckshot and Flechette are still the way to go. In BF3's low TTK world, you got be a great hipfire shot to compete with buckshot and flechette shotguns.

I think I tried frag ammo once with my M1014 to test and it was pretty crap so I switched back to buckshot. Pre patch though it was bullshit 1 hit kill from range, glad they nerfed it. The USAS is used a lot, but you lose your ammo pretty quickly.

After reading the comments, I suppose I must reverse my opinion. Frag ammo is just another thing for me to get used to; improvise, adapt, and all that.