Response and suggestions for the shotgun changes.
This got to be much longer than I originally intended, apologies. But to the Fun pimps and anyone balance-minded, I recommend reading it in full.
I understand why the shotguns were nerfed; early game, an auto-shotgun completely overshadowed the alternatives that could be purchased from the trader.
But I feel that the nerfs to the shotgun ammo types, indirectly lowering shotgun damage, were at once insufficient but yet heavy handed and did not solve the underlying problems.
However, I've been editing xml files all day post-nerf and I have a solution that I think solves a lot of issues with the shotgun weapon tree in general.
First and foremost, return the shotgun shells--both slug and shotshell--to their pre-169 values. Despite your having applied a 20% damage reduction, it shakes out to greater than that in practice, and the slugs that once felt decidedly more powerful than handgun rounds now feel anemic. A similar issue plagues the shotshells as well. However, I do agree that peak power being reached by the shotguns was too great, and I'm going to address that in the following.
I agree with the blunderbuss nerf; it's just a pipe-gun, and it has innate perforation. Even so, I'd recommend you raise the damage to 10 or 11, up from 9.6 and down from 12. I also recommend you increase the reload time from 3.9 to 6.5. Getting more intimate with the well-done reload animation aids with the old-fashioned feel of the gun, and harms the too-high overall dps.
I recommend the double-barrel be kept at 100% pre-169 base damage, and the ROF lowered to 500 to fix audio/visual issues--in practice, 1000 rpm is just blisteringly fast and unnecessary. I also think the reload should be 2 instead of 2.3 seconds long. However, I think that it is far too accurate, and should be given 1.5 more degrees of spread, horizontal and vertical, to try and make it less predictable and reliable. Also, I'd recommend 1 degree more vertical recoil, to decrease effective weapon handling. This is the early-game shotgun, and depending on RNG could be the player's mainstay for a very long time. A 20% damage hit harms this weapon by far the most.
Secondly, the pump shotgun. In its current iteration, I feel it's in a kind of limbo where it's not very interesting, though I agree with the damage penalties. To ameliorate this I recommend lowering the damage by 20% (still using pre-169 damage values, so essentially just bringing it in line with the current 169 iteration), and making the reload 2.85 seconds long instead of 2.3 (which also matches better with the sound byte used for the reload and changes the overall pace of the weapon). However, in exchange for these negatives, I recommend a positive; I suggest you add a flat 2, preferably 3, to the max and falloff ranges, bringing the shotshell to 8,13 from 5,10 and the slug to 12,21 from 9,18. These changes not only alter the pace of the weapon, but make it feel more impactful and like a viable alternative to the double barrel that you'd prefer at short-medium range instead of simply on account of capacity. Finally, I think you could increase the horizontal recoil by 1 degree, to make the shooter have to account for its still-fast rate of fire and slightly hamper the medium range performance.
Finally, the auto-shotgun. This is a tough nut to crack--currently, it has very little that differentiates it from the alternative shotguns, or indeed from other automatic weapons in the game right now. Despite its aggressive styling, it feels tame at best, and performance dissapoints, despite being very powerful early-game. Worse yet, the 169 changes did nothing to help this gun; if anything, it's even more muddled when compared to the pump shotgun it's supposed to replace.
I propose you turn this gun into a proper automatic. Please read to the end of this, because it sounds crazy, but a rate of fire of ~115 rpm, up from 70, makes it feel MUCH more responsive and snappy, which I was frankly surprised by. Despite being so fast, it has no issues with animation jostling or sound-clipping. It feels like a scarier, cooler gun, which matches the aesthetic. Already this sets it apart from the pump shotgun, which currently feels at best like the same gun but without a drum mag.
This is the ONLY buff I recommend for the gun. Now, for the costs. For starters, I recommend bringing the damage down by 35% (still of pre-169 values). This obviously harms the gun's late-game performance, but not as much as you may think. In exchange, however, it makes it feel more anemic early game and the other two shotguns significantly more appealing, especially when ammo-conservation feels tightest. On the flip side, it feels too jumpy with the new ROF in terms of recoil; A shotgun with a drum this big and a barrel this short wouldn't kick like such a mule, and it's annoying to readjust. SO, I recommend you reduce the vertical recoil to between 1.5 and 3, down from 4.2, but increase the horizontial recoil to +/-6 degrees deviation, up a very noticable 3.5 degrees per side or 7 degrees total. This makes the gun harder to hold on target, and impossible to account for by merely pulling the mouse down, while not being so uncontrollable that it still can't take advantage of being a shotgun. With these changes the gun feels more ramshackle and like it gives up some oomph and precision for its rate of fire.
I understand the aversion to giving the gun full-auto from the start, but I at least recommend you give it an innate, two-round burst. This makes it feel unique, cool, and offsets what feels like a ponderously large magazine. However, for this gun more than the other automatics, ammo count matters so I recommend removing random magazine deviation and also fixing the mag at 15 shots. That way, it's easy to keep track of your shot count both with and without the drum mag mod.
Speaking of the drum mag upgrade, the reload speed is too fast. I recommend it's changed to 2.85 seconds, same as the pump shotgun. It doesn't feel unnaturally slow, but it does look and feel more ponderous when using the inevitable drum mag mod which I feel is a good change.
Overall, I appreciate that TFP is looking into changing the shotguns and I don't think their concerns are misplaced. For ease of apprehension of the changes I've made in the above wall of text, I've attached an xml with the guns changed and my changes commented. I hope the above recommendations are given due consideration, and thank you for your time. I recommend using an xml viewer such as notepad++ to make the comments more noticeable and the text easier to parse.