On the recoil and sway of machineguns

[Carl Hamilton]

They seem a bit off, I believe the RPK recoil was increased in a somewhat recent patch. But on the insurgency wiki, it says it already had a higher recoil than that of the AKM. To me this makes very little sense, the RPK has a heavier barrel, and is overall heavier than the AKM, so why would it have a higher felt recoil?

The recoil is the biggest difference between RPK and the M249, right after the ammo count that is. However it seems that the M249 is just plain better recoil wise.

I suggest the recoil sees some changes for the sake of sensibility, the M249 is heavier overall and fires a less powerful round, so it having less recoil seems fair enough, however, the RPK should have less vertical recoil, being around 1 kilo heavier than the AKM while firing the same round should obviously result in significantly less muzzle climb.

While standing the RPK should have less sway than the M249, due to it being lighter, as it is easier to hold it up without being tired for a long period of time.

Currently the RPK is very hard to shoot in full auto accurately at range even when prone and with bipods deployed, while the M249 is fairly accurate even when standing.

I guess my biggest problem is still the RPK having more recoil than the AKM seemingly, unless the insurgency wiki is wrong.

Either way, i think that weight should affect sway negatively, and recoil positively, both guns would be better at one thing, as of right now i think that one gun is better at both and with no reason behind it.

Sorry for the long post.

[BurntCornFlakes]

Yes, but balance.

[Carl Hamilton]

The RPK will have an advantage in one area, the M249 will have an advantage in another area, what is unbalanced?

[🐺~Wolfie~🐺]

The RPK has a way too much recoil and thus this should be fixed. 5 Kg and Heavy barrel should compensate most of the recoil.

EDIT: There is no need to balance. The M249 is already a killing machine with it 200 rounds, high ROF and Low Recoil. The RPK has surely a fast reload, that's true, but if you take notice it has: 75 rounds, low ROF and High recoil which makes really no sense, actually, the one that should have more control overall is the RPK than the M249

[Lucas F.]

yeah, black rose is right, the m249 is terribly unbalanced (iit shouldn't be used as a rifle with 200 rounds).
a good way of balancing the m249 is by making it "clunkier" (more sway when without the bipod deployed, even slower reload and longer time to ADS and raise the weapon), and reducing from 200 to 100rnd capacity.

[Dr.Wholian?]

Originally posted by Lucas F. ® +ĐƗ1ØØØ:

yeah, black rose is right, the m249 is terribly unbalanced (iit shouldn't be used as a rifle with 200 rounds).
a good way of balancing the m249 is by making it "clunkier" (more sway when without the bipod deployed, even slower reload and longer time to ADS and raise the weapon), and reducing from 200 to 100rnd capacity.

Exactly. Increased recoil is exactly the WRONG way to balance LMG's. It only serves to diminish efficacy at the true purpose of LMG's (suppresively-accurate volume of fire over all ranges) while entirely failing to stop problematic CQB run and gun behavior.

In order to stop LMG run-and-gun, what is absolutely required is:

1) slower ADS time based on the weight of a weapon
2) larger free-aim area based on weight of a weapon
3) standing/unsupported sway increased based on weight of weapon
4) weapon collision system needs to actually be utilized instead of shelved with microdick values

The M249 200rd box is a complete joke. It should be replaced with 100rd sacks.

Ultimately, the RPK should be replaced with the RPD, which has a 100rd drum and heavier weight, making it closer to a "7.62 SAW" in terms of recoil.

Originally posted by Carl Hamilton:

The RPK will have an advantage in one area, the M249 will have an advantage in another area, what is unbalanced?

The advantages are totally out of scale. IRL, recoil values are thus:

M249 - 1.5 ft-lbs
RPD - 2.3 ft-lbs
RPK - 3.5 ft-lbs
M16A4 - also 3.5 ft-lbs
AKM - 7 ft-lbs

Even with these realistic values, though the RPD has lower recoil than an M16A4 or AKM, it is still distinct from the M249, because of the 7.62x39mm cartridge. Its recoil is not quite as low, but it has higher damage in extremity shots and against concrete/mudwall barriers.

[Carl Hamilton]

Since I do not understand the imperial system, it would be nice if you could walk us through the calculations for energy, or convert it to normal units.
Also I am curious, does the calculation take into account that the AKM and RPK has muzzle brakes.

Other than that, the RPK shouldn't be the RPD, it's a rarer gun, and the M249 seems fine for 200 bullets, but maybe the reload time should be more realistic too. https://youtu.be/g8sa8QFNEGI?t=285

[Dr.Wholian?]

Excuse me, the RPD is hardly "rare".

http://images.fineartamerica.com/images-medium-large/a-captured-fedayeen-weapons-cache-stocktrek-images.jpg

http://ipsnews.net/pictures/taliban_weapons.jpg

From someone first hand experience:

https://strikehold.wordpress.com/2009/04/26/trunk-monkies-and-rpds-in-iraq/

"One of the guns I saw in plentiful supply and that became an early favourite with Security companies was the RPD. They were also cheap...

...When I first went to Iraq in 2004 there were hundreds of RPD LMGs being used by the Iraq army, Iraqi police, most Contractor companies were using them and of course we were on the receiving end of the bloody things being used by the Militia and all the other disgruntled factions."

If we are talking about commonality, then the PKM is undoubtedly the most common machinegun used by insurgents - much more so than either the RPK or PKM. Where the ♥♥♥♥ is it in Insurgency? It's nowhere. Meanwhile in Insurgency, there are MP-40's and M1A1's everywhere, despite being impossible to find in Insurgent use IRL. Where commonality is concerned, this game is FUBAR and needs a lot of work.

The role of a 7.62x39mm machinegun in Insurgency is not to represent the most common insurgent machinegun IRL, because it's just NOT. The PKM is much more commonly used than either the RPK or RPD, and due to its heavier 7.62x51mm cartridge, its recoil and power is absolutely nothing like the M249.

Thus, the role of a 7.62x39mm machinegun in insurgency is really to provide an insurgent machinegun with similar capabilities to the M249 SAW. The RPD obviously achieves this much better than the RPK due to its weight, controllability and ammo capacity, so it's a better choice.

And no, there is nothing balanced about 200rd box. Do we upgrade the M16 or M4 to 60rd mags just because 5.56mm is "lighter" than 7.62? No. Doing so would not be balanced. So why is it supposed to do this with the M249 when ANY other machinegun in the game will be limited to 100 rounds max? The 100rd sack is much more common for the sort of on-the-move operations represented in Insurgency and allows a much better balance, particularly if LMG recoil is to have ANY hope of NOT killing immersion with horrible exaggerations.

Info on recoil formulas can be found here:

https://en.wikipedia.org/wiki/Free_recoil

I use this calculator:

http://www.handloads.com/calc/recoil.asp

For weight I use the average between an empty and fully loaded gun, and make my own adjustments for differences in powder, stock differences, and muzzle device.

The RPK (unlike the RPK-74) does not have a muzzle device, and the slant brake on the AKM makes a very tiny difference. The only milpec AK device which really does make a difference is the AK-74 brake design, and even that will not make a 7.62x39mm shoot like a 5.56mm AR. For that you would need an aftermarket compensator like the ones frequently sold on .308 and 6.8 AR carbines these days.

Honestly the actual units don't really matter, since the in-game values don't use either imperial or metric units. What DOES matter is the proportions: a weapon which has twice the recoil of another IRL should have twice the recoil in-game. If you get the proportions right, then everything will feel properly to-scale with the correct tactical differences.

This custom graph spells out the big picture pretty clearly:
http://i1288.photobucket.com/albums/b500/Gnalvl/insvsrl_zpsf1d4fefd.png

[Lucas F.]

@dr.wholian
I agree completely with your points. and i hope you end updating your realism mod, it just makes the game better overall.

[SwagHauler]

Originally posted by Dr.Wholian?:

Originally posted by Lucas F. ® +ĐƗ1ØØØ:

yeah, black rose is right, the m249 is terribly unbalanced (iit shouldn't be used as a rifle with 200 rounds).
a good way of balancing the m249 is by making it "clunkier" (more sway when without the bipod deployed, even slower reload and longer time to ADS and raise the weapon), and reducing from 200 to 100rnd capacity.

Exactly. Increased recoil is exactly the WRONG way to balance LMG's. It only serves to diminish efficacy at the true purpose of LMG's (suppresively-accurate volume of fire over all ranges) while entirely failing to stop problematic CQB run and gun behavior.

In order to stop LMG run-and-gun, what is absolutely required is:

1) slower ADS time based on the weight of a weapon
2) larger free-aim area based on weight of a weapon
3) standing/unsupported sway increased based on weight of weapon
4) weapon collision system needs to actually be utilized instead of shelved with microdick values

The M249 200rd box is a complete joke. It should be replaced with 100rd sacks.

Ultimately, the RPK should be replaced with the RPD, which has a 100rd drum and heavier weight, making it closer to a "7.62 SAW" in terms of recoil.

Originally posted by Carl Hamilton:

The RPK will have an advantage in one area, the M249 will have an advantage in another area, what is unbalanced?

The advantages are totally out of scale. IRL, recoil values are thus:

M249 - 1.5 ft-lbs
RPD - 2.3 ft-lbs
RPK - 3.5 ft-lbs
M16A4 - also 3.5 ft-lbs
AKM - 7 ft-lbs

Even with these realistic values, though the RPD has lower recoil than an M16A4 or AKM, it is still distinct from the M249, because of the 7.62x39mm cartridge. Its recoil is not quite as low, but it has higher damage in extremity shots and against concrete/mudwall barriers.

+100 Good Doctor!

[Carl Hamilton]

I agree they aren't balanced, i think Dr. Wholions suggestion on weight, recoil and sway, mirrors mine quite well.

[< blank >]

Originally posted by HiD | BurntCornFlakes:

Yes, but balance.

You mean like the map balance? ...wait... Nevermind.

[Carl Hamilton]

@Dr. Wholian, I just read tests done with the AKM AK74 and M16, it says the AKM has 7.19 joule of energy which is 5.30 ft-lbs. AK74 has 3.39 joule and the M16 6.44 joule.
I felt like 7 ft-lbs was a bit much.

[Dr.Wholian?]

You're referring to the Wikipedia example numbers, which I've seen before and pretty blatantly contain mistakes/typos.

Take a look at the Remington 700 in .223. The weight of the rifle is almost the same as the M16A2, it's allegedly shooting the same weight bullet with almost the same powder charge and the same velocity, yet the recoil numbers listed are signicantly lower (5J / 3.7 ft-lbs vs. 6.44J / 4.75 ft-lbs).

This could be partially explained by the fact that the standard issue M16A2 round is 62gr and not 55gr, despite the fact that Wikipedia has listed 55gr for the M16A2 calculations. However, the velocity listed is also high for a 62gr bullet, at 3250 (normally M855 clocks around 3100 fps). If the 62gr weight was accidentally calculated with the 55gr velocity, it would give you abnormally high numbers

In any case, it's clearly got errors and any other source you consult will list lower recoil amounts for 5.56mm cartridges, and higher amounts for 7.62x39. Look at the graph on the following page:

http://www.shooterscalculator.com/recoil-calculator.php

Try punching in the following numbers and see what you get:

AKMS -
bullet weight: 123gr
powder charge 24gr
velocity: 2350 fps
rifle weight: 7.3 lbs
full magazine weight: 1.8 lbs (averages to 8.2 lbs weight)

M16A4 -
bullet weight: 62gr
powder charge 26gr
velocity: 3100 fps
rifle weight: 7.18 lbs
full magazine weight: 1.14 lbs (averages to 7.75g lbs weight)

4.25 ft-lbs for the M16A4 vs. 6.47 on the AKM (an increase of 1.52)

You can also try these numbers here:

http://www.handloads.com/calc/recoil.asp

3.59 for the M16A4 vs. 5.73 for the AKM (an increase of 1.6)

Additionally, this is not taking into account that the M16A2 has a straightline stock, while the AKM stock is angled and works like a fulcrum to increase recoil. What's worse, AKMS stock is both angled AND a simple wire design which offers even worse ergonomics and as Swag Hauler has described, can actually bend ever so slightly during shooting, causing more severe muzzle deviations than with even the standard wood stock.

Consequently, if you ever shoot these weapons yourself or talk to someone who has, the consensus is that .223/5.56 has "almost no noticeable recoil", while 7.62x39mm has a kick to it which does require a little more effort in keeping rapid fire shots on target. If you can find a video on youtube of someone shooting both weapons back to back and look at their muzzle rise, you will generally see that the .223/5.56's muzzle jumps about 1cm or less with every shot, while a 7.62x39mm AK jumps 2 or 3 cm per shot.

Both are considered "intermediate" cartridges, because a 7.62x51mm, 7.62x54mm, or .30-06 will kick twice as hard as an 7.62x39 and produce twice as much muzzle rise. However, 5.56mm and the AR design is a very different approach from 7.62x39mm and the AK design, with substantially different handling. This is why is takes an average weight of around 12 lbs in the RPK to get comparable controllability to the M16 (try punching this into the calculators if you don't believe me).

[Carl Hamilton]

If someone actually did a free recoil test, and arrived at a result, I would consider this more reliable.

Theoretical calculations are never as good as experiments. The wikipedia page doesn't contain errors, it accurately quotes it's own source.

You calculation doesn't take into consideration the effect of the muzzle brake.
People who I talk to who has fired the gun variate in their account, but personal anecdotes isn't good evidence anyway.

[Dr.Wholian?]

Here is a direct comparison of an AK with out a brake and AK with aftermarket brake vs. an AR w/ standard flash hider:

http://youtu.be/0aKC3dYx02M?t=51s

Just in case there is any more doubt about the huge gap in handling between an AK w/ out a brake vs. an AR:

https://www.youtube.com/watch?v=R2t1MtQruNo
https://www.youtube.com/watch?v=D6tMyIASC5g
https://youtu.be/T4yhyn57aro

Of course, all muzzle brakes are not created equal, and here are two comparisons of the the common slant brake compared to other aftermarket designs:

http://www.thetruthaboutguns.com/2012/12/chris-dumm/ak-muzzle-device-test-part-1-recoil-reduction/

http://www.youtube.com/watch?v=1LbORX_ayHI

While the aftermarket brake in the very first video appeared very effective, in practice the milspec slant and 74-style brakes are not enough to match an AR:

http://youtu.be/JYLRe4sfaHs?t=33s
http://www.youtube.com/watch?v=G4OmlORv6qs
http://youtu.be/W9e9BSnDzxI?t=15s

In the last one, the shooter had to run double-taps to get the AR to rise the same amount as the AK-103.

So you see, the innate recoil of 7.62x39 and the AK's non-straightline configuration are so disadvantageous that adding a military-issue brake only brings it about halfway to recoiling like an AR.