It was in response to the question of whether Guardsmen should have Toughness as a cheap advance. Someone asserted, in favour of the idea, that melee basically sucks compared to pistols. That seemed unlikely to me, so I crunched the numbers. In the process, I wrote what basically functions as a "how to rock as a Gaurdsman" guide. So I thought I'd share it here.
Beware: it's a long read.
"I'm having trouble seeing how top-end pistols are at all competitive with melee weapons. Generally, from rank 1 to rank 8, melee weapons do better against high armor targets, and guns against low armor targets. Melee characters can balance this out by early game by carrying around a auto-shotty with a pistol grip and/or recoil gloves, which their high WS and Manouver makes somewhat easier to use. Once they get rolling with the right midgame weapons and talents, there's no need for this (but it's still fun).
Likewise, Gaurdsmen are the only class that actually have both multiple cheap combat stats and are able to access every combat stat as either a cheap or average cost upgrade (Clerics and Sororitas each have one cheap combat stat and the rest average). Especially delicious is the cheap Strength, the basis of both melee devestation and being able to actually carry a heavy weapon. No one else gets it as a cheap upgrade, which is probably why some of you actually think that melee sucks.
What this means is that there's no excuse for a Guardsman not to hit every one of the awesome talents like Hard Target and True Grit that unlock at 40 points in a combat stat.
Also, while Guardsmen don't have as many options for investigation skills and talents, they are there. And while a melee psyker is busy spending 1250 xp to push his agility up to 40, you can be taking the five investigative talents your savings in the same stat lets you afford. If you want more selection, take Feral Warrior (tracking and stalking skills), Chaliced Commisartiate Officer (investigation), and later Bloodsworn (both in one). Or talk your GM into letting you take Legate Investigator or Tyrantine Shadow Agent for the social skills.
On to pistols vs melee:
The only pistols I see keeping up at all are the Inferno Pistol and the Mauler Boltgun. There are some nice SP and Las Pistols which can fire on semi or full auto, but they don't scale up against armor terribly well. Some of them can use Manstoppers, though, which helps a lot. The best candidate is the impressive Orthlak Mark IV, which with Manstoppers is a poor man's boltpistol.
The Inferno has a single shot, 2d10+4 E, Pen. 12. It's impressive and will cut through anything. You'll need to reload a lot. It's a half action each gun with Rapid Reload, which will eat up every fourth turn. Of these guns, only this one can effectively Jam. The Mauler can be reasonably bought as a custom weapon which counts as Best in its true owner's hands (special rule), while the Orthlak can be easily bought outright at Best Quality.
The Mauler does 1d10+5 X, Pen 4,and fires on semi-auto at a rate of 3. You'll need to reload every third turn if you fire on semi-auto. On some interpretations of the latest erratta, it also has tearing.
The Orthlak does 1d10+4 I, Pen 3 (with Manstoppers), and fires an impressive six-shot burst on full auto. Again, reload is every other turn at a half-action with Rapid Reload.
It's safe to assume a character specializing in pistols will have a nice 30-40 BS starting stat, especially if they are from Gunmetal City. This will be easily trained fully by endgame, up to 60. I'm not sure if Short Range bonuses apply. The rules clearly state that PRB does not, and in melee one is at PBR. I'll assume that Short Range does OR the weapons have Targeters. Either of these brings us up to 70. The Orthlaks fires at Full Auto, granting +20 more; the Maulers at semi-auto, granting 10; and the Infernos are best fired as a dual shot, which allows the use of a red dot, adding 10. It is safe to assume this character will have Mighty Shot, adding 2 damage to each shot.
The Inferno will thus be a combined attack with both weapons for 4d10+12 E damage (avg. 17 each 34 total) with a 90% hit rate. The armor will be applied against both attacks- who cares with a Pen. of 12. Toughness will be applied only once against the whole attack, making this nice for taking down enemies with Unnatural Toughness. The only downside is that one dodge spoils the whole thing.
The Mauler will be a semi-auto burst at 80 WS. Every two degrees of success adds one more hit from each gun. So, on roll of 61-80, you get two hits; on a 41-60 you get four; and on a roll below 40 you get six. Each hit is 1d10+7 (avg. 13). So, odds are 20% of a miss, 20% of 2d10+14, 20% of 4d10+28, and 40% of 6d10+42. Hey, I never said pistols sucked! You'll also be broke, but they'll be dead. Dodging is possible, although they'll need three degress of success to negate all the hits.
Finally, the humble Orthlak fires a fully-automatic burst at 90 WS and gains another hit for each degree of success up to six hits per gun. So, 10% miss, 10% two hits, 10% four hits, 10% six hits, 10% eight hits, 10% ten hits, and 40% twelve hits. Let's just calculate out the full twelve hit value:
12d10+72. Yow! However, with a Pen. of three, in practice this is much, much less. On the other hand, if you didn't get a Righteous Fury in all that then the Emperor probably hates you because you think bad thoughts. Also, it would take six degrees of success to dodge all this fire. Still, to demonstrate the armor issue, each of these hits averages 11 damage. With Pen 3., you'd have to hit with the entire burst for someone in Carapace and decent toughness to be phased. The problem is, at endgame, you're looking at enemies who have 5+TB and high armor. 8-10 TB alone isn't unusual, meaning that the average hit from this otherwise impressive weapon will do 1 damage. Scatter weapons, incidentally, suffer from the same problem.
Okay, so all these are pretty good. Lots of damage, and the biggest downside is that you lose out on every 3-4 turns for reloading. So what does melee bring?
Well, there are some options, but I'm going to have to go with two Power Fists.
Like our gunslinger there, we can safely assume that our bruiser has 30-40 in his key stats, WS and Str. Again, we'll be optimistic. Likewise, both of these are cheap-o for a Guardsman to raise, so we're looking at 60 base WS and 60 base Str. Likewise, anyone walking around with two Power Fists probably has power armor to match. So let's make that 80 str. Again, our Bruiser probably has Crushing Blow, so each attack gets +10. Because two-weapon melee talents aren't as good as their ranged equivalent, he'll take a -10 WS hit on the off-hand unless he uses Dual Strike. This is only really a good option against high toughness enemies, however. Sadly, there's no real chance of being able to afford a Best Quality Power Fist. There is a good chance, however, that a given attack will benefit from either High Ground or Hatred, although I'll assume neither.
So, since Power Fists do 2d10+(SBx2) damage with a Pen. of 8, we're looking at 2d10+18 each hit (avg. 29). Lightning Attack allows three attacks with the main hand and one with the off. Each main hand hit has an independent 60% chance of hitting, and the off-hand has an independent 50% chance. Under normal circumstances, only one of these four attacks can be dodged or parried. I don't feel like doing the math, but the total damage if all connect is 8d10+72 damage. Armor isn't much of a problem in this case. Also, there is no full turn reloading every few turns.
If the hit rate becomes a problem, there are a few options. One is to move to Frenzy and Furious Assault. This gives +10 to WS, Str, WP, and Toughness with -20 to BS and Int. You also have to attack the nearest enemy if possible and are immune to prettymuch everything. You have to use All-Out Attack, which gives +20 WS, and can use with with Furious Assault to make two All-Out Attacks. This yields two attacks with a 90% chance to hit each at 2d10+20 (avg. 31), for a total of 4d10+40. This fits nicely in between the 40-60% range on the damage of my pick for best bolter.
Another option is to move over to a sword, which allows the use of the Blademaster talent, which allows one reroll on a missed swing per round, as well as access to Best Quality weapons. There are some options here, but my favourite is a best-quality Eviscerator, a Chain weapon which deals 1d10+10 damage with Pen 5 and Tearing, and a slight chance of backfiring on a truely terrible miss. With SB and Crushing Blow, that's 1d10+20 for an average of 25.5 damage per hit. A Lightning Attack with one of these is three 70% chance hits with one reroll. If all three connect, the total is 3d10+60 damage. Likewise, this can be used with Frenzy instead for fewer, but harder and more reliable hits.
It's really the penetration and average damage that make the difference. Only Melta and Plasma weapons can really keep up with melee in terms of Pen, excepting some rather nice Heavy weapons and a few Basic weapons. And in average damage, needed desperately against high-toughness enemies, the contest is almost purely between the relative easy of using melee weapons and the raw power of heavy weapons. Pistols can get in this game, but they really shine best against less resilient enemies (of which there are some scary examples, Nurglings come to mind).
Most of this scales down nicely to early game. Autopistols are certainly impressive (heck, some people might be able to afford the Orthlak as a starting weapon), but won't exactly be scoring six degrees of success yet.
As for melee, A Best-Quality Mono-Punch Dagger (1d5+2, Pen 4, +10 WS) costs 90 thrones, making it a great starting weapon. A Best-Quality Mono-Bastard Sword (1d10+2, Pen. 3, +10 WS) isn't much pricier at 170 thrones. Moving up a little, a Best Quality Mono-Greatsword (2d10+1, Pen 4, +10 WS, two-hands to use) costs 740 thrones. Or you could get a normal quality Eviscerator. Once ranged characters are moving on to Bolters, melee characters graduate to Power and Lathe Weapons (or Force Weapons if they're Psykers- these break all of this and eat a bowl full of pistols for breakfast in the morning). The stats for Power Weapons are straitforward. A Lathe Greatsword has 2d10+3 damage, Pen. 5. Give it 40 str and Crushing Blow, and we're looking at 20 average damage per hit that thinks that Carapace Armor is funny.
By this point, a Guardsman can easily have Frenzy and Furious Assault. Enjoy. "