Why use a SMG instead of a machine pistol?

[ClayDowling]

Originally Posted by Icelander

Doesn't it bother you if the game system doesn't reflect what you know from real-life experience are noticable differences?

Not in the least. I don't let that stop players from making wizards in settings where that's appropriate, even though I've never met a real wizard.

In practice I accomplish a balancing of problems like this via narrative choices, or imposing non-numeric penalties after the fact. If the PCs want to use a .44 magnum with hunting loads, I let them. Then I give them a sore wrist for the rest of the day. There's nothing in the rules about it, but I've never known anybody who owned a .44 magnum who didn't regret the purchase the first time they tried to use a hunting load.

We aren't playing this like a wargame. GURPS is a framework for us to tell stories and let us be heroes for a few hours on a Saturday. So inconsistencies don't really bother us unless they're screw up the story. Which they haven't so far.

[Kromm]

Originally Posted by copeab

I don't think this is a good comparison, at least for PC weapons. A PC that would want an automatic Mauser with shoulder stock isn't going to pick a Greasegun or Sten instead. He'll go for a Thompson or Suomi.

This touches on why we don't stress Cost and LC more than we do, though: They're probably the most important real-world stats, and often the reason why weapons are adopted. However, PCs essentially run roughshod over them, begging, borrowing, and stealing to use their favorite guns no matter how costly, rare, or controlled.

I'm fine with that, personally. The only downside is that 90% of these "Why isn't X as good as Y?" debates come about because people ignore legal and logistical issues, and immediately segue into combat stats. That's more in the category of "damned if we do, damned if we dont," though! :)

[copeab]

Originally Posted by Ulzgoroth

Having been reading The Ogre Book recently, this reminds me strongly of the playtest problem described therein...

I remember that, at least the general intent: you have to test the stupid ideas, too.

[gilbertocarlos]

Originally Posted by HANS

Here are the reasons why machine pistols are inferior to SMGs:

1. Ergonomics. All machine pistols have stocks that are too short, too low, and otherwise less perfect than a full stock on a SMG. All machine pistols are difficult to hold with the off-hand because they are too short. They often also have problematic centres of gravity, which means that muzzle rise is worse than expected. Machine pistols are terrible to hold unless you have super short arms and a crooked neck.

2. Rate of Fire. Despite what gamers think, high RoF is a bad thing in ANY automatic weapon other than a minigun. High RoF means lower reliability, less endurance, less controllability. Designers try to avoid this if at all possible. Machine pistols invariably have high RoF, because the operating mass (the slide) is too light. This can't be solved except by complex mechanical means (burst limiters or rate reducers), which increases complexity and cost.

3. Magazine capacity. Machine pistols generally have limited magazine capacity, because their whole reason for existance is their small size. Also, big magazines further reduce ergonomics (making their pistol grips too bulky) or are simply not possible from a design standpoint.

4. Effective range. Their short barrels cut down on muzzle energy, which together with their short sightlines has unfavourable impact on Dmg, Acc, and Range.

5. Machine pistols cannot be build as cheaply as some of the more simpler SMGs, because they are more complex.


All of these means machine pistols are inferior to SMGs in every conceivable way, except their size and weight (Bulk). They only exist because sometimes, that's the most important consideration (eg, if you're a bodyguard or bank robber). Another reason has nothing at all to do with performance, but availability, something that is not covered by GURPS stats except, to a minor degree, LC. The old Mauser machine pistols (and their many variations) only exist because at the time of their design, there was an international ban on importing military arms to China, and (machine) pistols were not counted among those. A third reason for machine pistols is sheer technical interest. Some were designed simply because the designers could.


Unfortunately, GURPS cannot replicate all of these minor nuances. It is, as stated above, a granularity issue.

Cheers

HANS

I'm not talking about RL, I'm talking about GURPS, in GURPS, there Machine Pistols(and ultra light SMGs) don't have problems.

1) Ergonomics: Not covered in GURPS(this problem arrives also with bullpup rifles).
2) Rate of Fire: GURPS don't have any disadvantage from higher RoF, and at any time you can choose to shot less than full RoF.
3)Magazine Capacity: If you ignore size, and put a larger magazine, according to GURPS, you get a -1 bulk, a weapon as good as a smg, but lighter.
4)Effective Range: GURPS gives the same Acc(exception MP5, M1921(both very expensive) and PDWs) and range to SMG and pistols, about damage(using 9mm for example) is 2d+2 vs 3d-1, that's less than 6% difference.
5)Price:That's the only connection I can find between GURPS and what you said.

Even though GURPS cannot modelate this because of granularity, shouldn't be a higher recoil for very light machine pistols? even the glock 18(weight of 2.6 fully loaded, 2.1 with a 17 round magazine) have recoil 2.

As well, can anyone tell me how recoil is calculated?

[Icelander]

Originally Posted by HANS

Meh. We cannot replicate tons of things in the game, by far not confined to gun stats. It's lunacy to expect that of a game, and it simply cannot work with such a confined set of parameters as the few stats we have for guns.

For that small part of this ton of things that authors, playtesters and players deem important, rather than irrelevant and boring, we have the choice of adding various and completely optional rules that nod toward it. In GURPS Tactical Shooting a lot of things that were previously not accounted for in the rules, even if they were known by people who shoot guns, acquired an optional rule more closely in line with reality, at least enough to avoid the most striking perverse incentives.

Granted, we have a decade or so until GURPS 5e, but it's worth thinking about which stats to retain and which, if any, to add in order for the rules to be able to represent reality as best as possible while also remaining elegantly simply to use. For those leaning toward the 'accurate simulation' horn of that dilemma, of course, there are optional rules.

As far as it is possible within the system as it stands, no reason not to contemplate these optional rules right now.

Originally Posted by HANS

As I've already said, the control issues can be modelled by simply worsening Rcl by +1.

Can't do that, it would never do. Then you'd have a case where a weapon firing the same cartridges magically became less controllable with the addition of a stock, merely because it now has an option of fully-automatic fire.

The Rcl in semi-automatic fire can't be greater than the Rcl of a similar pistol, because that makes no sense. A 4.5 lbs. weapon with a stock won't be harder to control than a 2.1 lbs. one without it if they are firing projectiles of the same size and velocity.

You'd need to establish a RoF beyond which the Rcl was worsened by +1. You could say 4+, but that would mean that there was no advantage to a fully-automatic setting beyond a trained operator simply using Fast-Firing and a normal semi-automatic pistol. Of course, that's not necessarily a bad thing and it seems to reflect reality. If we wanted to make it better to have a purpose-designed 'machine pistol' when using a pistol as a suppression weapon (however misguided that usage might be), even if just marginally better, we might set the RoF at which the Rcl increase kicks in at 6+ or even 9+. I'm not convinced that that's warranted, but then again, I've never used a pistol with a higher rate of fire than semi-automatic.

Originally Posted by HANS

Meh. Strength of the user has little to do with the control of automatic weapons. Most of it is technique (Guns skill).

Cheers

HANS

Within typical human levels, I'm sure that skill is the most important factor. GURPS, however, has to work with ST 6 Grey Aliens and ST 25 Proud Warrior Race Guys as well as humans. And it's a fact that the less energy and momentum is involved in recoil compared to your own size and strength, the less skill you need to control it.

I'm not a skilled shooter, but being 6'1" and some twenty stone, I find that I don't much notice the recoil of a 12-gauge shotgun and follow-up shots with a semi are easy. For a 100 lbs. girl, years of practise might be required to acquire sufficient skill to overcome the simply fact of physics that she's throw far more off-balance by the recoil.

I absolutely think that with enough skill and the right Perks, a comparatively slight shooter could learn to manage even a hard-kicking gun with ease. I just think that it's naturally easier for those of us who are less slight to do so.

In GURPS terms, the difference between a slight shooter with ST 8, skill 15 and Style Perks to allow her to use the weapon at a much higher effective ST and one who just has ST 14 and skill 10.

[Anthony]

Originally Posted by Icelander

Can't do that, it would never do. Then you'd have a case where a weapon firing the same cartridges magically became less controllable with the addition of a stock, merely because it now has an option of fully-automatic fire.

Easily fixable by increasing the Rcl of all pistols. Rcl 2 pistols should be .22LR and .25ACP, not 9mm.

[Kromm]

Originally Posted by Polydamas

GURPS rules need to be written for people who have no practical knowledge of the domain in question though. The Hans-Christian Vortischen of the world know what is realistic; the rules need to be clear for people who have never touched a working firearm. Its a shame that GURPS doesn't cover many features of smaller, lighter weapons but it does give them several disadvantages.

But this is all academic. In real life and in games, people rarely have free choice of small automatic weapons. Professionals use what they are issued, and civilians and criminals use what is available. If your character doesn't like what the black-market arms dealer has available, the dealer can't just mail order in what he does want!

There's also the reality that no playable game can have infinitely fine grain size. You can mathematically prove that a game intended to simulate the world with less complexity than all the world's moving parts is restricted in its ability to carry out the simulation, and you can't prove but can easily observe that the psychological fatigue caused by a game with even a small fraction of such complexity would be unplayable. Thus, some things necessarily slip between the gridlines on the mesh. In the case of man-portable weapons, there's the added issue that you can measure recoil velocities and calculate moments of inertia until the cows come home, and shoot millions of rounds into gel, to prove that A is superior to B . . . but shooters will stick to their myths anyway. Thus, even a perfect, infinitely complex reality simulator would run afoul of opinion.

For these situations, you have GM fiat, as ClayDowling said. That's the fudge factor. We back this up with all the research notes in weapon descriptions: Hans doesn't list production runs, years of adoption, and the qualitative opinions of historical users to show off. He has to dig around to find it. That information is there so that GMs can make intelligent calls as to what's available and preferred.

[Bruno]

Originally Posted by gilbertocarlos

4)Effective Range: GURPS gives the same Acc(exception MP5, M1921(both very expensive) and PDWs) and range to SMG and pistols, about damage(using 9mm for example) is 2d+2 vs 3d-1, that's less than 6% difference.

You can't just hand wave away a benefit for one after claiming there's no benefit to it :D 6% is statistically significant.

[HANS]

Originally Posted by gilbertocarlos

1) Ergonomics: Not covered in GURPS(this problem arrives also with bullpup rifles).

This is one aspect of Rcl.

Originally Posted by gilbertocarlos

2) Rate of Fire: GURPS don't have any disadvantage from higher RoF, and at any time you can choose to shot less than full RoF.

No. You are restricted by minimum RoF (p. B408). High RoF also has the very real effect that the faster you shot, the faster you stand there with an empty gun. Finally, note that the Rapid Fire table (p. B373) is not linear. Past RoF 16, you get much less return for ever more bullets spent. Most machine pistols have RoF 15+.

Originally Posted by gilbertocarlos

3)Magazine Capacity: If you ignore size, and put a larger magazine, according to GURPS, you get a -1 bulk, a weapon as good as a smg, but lighter.

It's not "as good." It's just roughly the same size and weighs less. Which is actually realistic, by the way.

Originally Posted by gilbertocarlos

4)Effective Range: GURPS gives the same Acc(exception MP5, M1921(both very expensive) and PDWs) and range to SMG and pistols, about damage(using 9mm for example) is 2d+2 vs 3d-1, that's less than 6% difference.

Regarding Acc, yes. That's because there's only Acc 2 or Acc 3 to chose from. Granularity. Range, no. A machine pistol in 9x19mm has Range 160/1,800, a SMG 170/1,900. Not much, but realistic. Dmg, no. The difference is small but realistic.

Originally Posted by gilbertocarlos

Even though GURPS cannot modelate this because of granularity, shouldn't be a higher recoil for very light machine pistols?

I've already said, twice, that a usuable solution would be to worsen Rcl by +1.

Cheers

HANS

[Ulzgoroth]

Perhaps if the ergonomics of stocked shooting of pistols are bad, we might give them a -1 to Sighted Shooting?

Originally Posted by copeab

I remember that, at least the general intent: you have to test the stupid ideas, too.

And in particular the ones that fly in the face of wisdom drawn from the real-world analogue. (In that article the illustrative example was uphill bayonet charging into prepared positions in a US civil war game.)