Feature #4841

Realistic jam rates per gun

Added by th3flyboy about 7 years ago. Updated about 3 years ago.

Status:Assigned Start date:09/24/2009
Priority:Normal Due date:
Assignee:q1184 % Done:


Target version:Arma 3
Component: Affected Version:
Close Reason:


It would be preferable to have jam rates on guns based on real world specs rather than just a predefined jam rate for all guns as it is now. This would give a very good reason to use an AK or HK416 over an M4 or M16. Currently, all guns jam the same rate.

Related issues

related to A.C.E. for OA - Feature #15343: System of overheating for all the weapons. New 11/22/2010


Updated by rocko about 7 years ago

  • Assignee set to q1184

Updated by Scubaman3D almost 8 years ago

I don't know if we have enough data to recreate real life jame rates.

I will say that it is was rare to see a gun jam in ACE1.

Updated by Sickboy almost 7 years ago

  • Target version set to 1.0.0

Updated by rocko almost 7 years ago

  • Target version changed from 1.0.0 to 395

Updated by mr.g-c almost 7 years ago

Scubaman3D wrote:

I will say that it is was rare to see a gun jam in ACE1.

Maybe a bit too rare i think, especially for the Jam-master M4.... :-) I remember we had a huge Topic about that issue/suggestion in the older ACE1-Forum (the Vbullentin one), with a lot of first-hand soldiers experience from the field with typical issued US-Weapons.

Updated by rocko over 6 years ago

  • Category set to Complex
  • Status changed from New to Assigned
  • Priority changed from Normal to Low

Updated by CarlGustaffa over 6 years ago

Jam-master M4 :)

If you read those "what gun" threads at BI forums, you'll notice that "exploits" are still being used. One popular one is the infamous C-Mag.

Suggestion: Make weapons using C-Mag extremely prone to jamming, unless used in a proper weapon like the automatic rifle version of the XM8, which should be better built to dissipate heat. I have no idea how the C-Mag "work" in ACE given pros and cons though, it's not my favorite weapon family. I guess I could live with M4 being more prone to jams if newer guns like XM8 and (hopefully) upcoming HK416 are less prone to it.

The best solution would be if it was possible (via triggers i.e.) to set a jam factor. In areas/weather with nasty conditions, jamming would be more frequent than in nice conditions. Crawling in rain vs standing in sunshine if you like :)

Updated by rocko over 6 years ago

  • Target version changed from 395 to Planned (Needs Contributors)

Updated by rocko over 6 years ago

  • Target version changed from Planned (Needs Contributors) to 395

Updated by rocko over 6 years ago

  • Target version changed from 395 to 1.5 (OA)

Updated by Xeno about 6 years ago

  • Target version changed from 1.5 (OA) to 1.6

Updated by rocko about 6 years ago

  • Priority changed from Low to Normal

Updated by q1184 almost 7 years ago

Ok, ok, I'll see what i can do, geez.

Updated by Sickboy almost 6 years ago


Updated by q1184 almost 6 years ago

What would be the relative coefficients of jamming probability for different rifles if we take, say, AKM as a basis (coefficient = 1)?
For example:
AK: 1
AR15: 5
HK416/17/SCAR: 1
M249: 3
I don't have much time to invest in google-research, so help appreciated :)

I also plan to make drum mags more prone to jamming and possibly make rain increase the jamming probability.

Updated by rocko almost 6 years ago

I would use these values as base. Sounds good to me.

Updated by Sickboy almost 6 years ago

Status? Or move up?

Updated by q1184 almost 6 years ago

  • Target version changed from 1.6 to 1.7

More important things on the table right now.

Updated by rye almost 6 years ago


At the very bottom - page 17 - there is information about the percentage of weapons malfunctioning.

"One source noted that the first dust test new M4s had 9,836 jams in 60,000 rounds – almost one jam every 6 rounds. The Army kept working on the test until they figured out a “generous lubrication” approach that used far more than the manufacturer recommended, but lowered jams to 1 in 88 rounds." - http://www.defenseindustrydaily.com/the-usas-m4-carbine-controversy-03289/

But on talking to an ex-RAR soldier he said he didn't get one jam after 2,000 rounds at least.

"Nah, i didnt get one jam, i would have put maybe 2000 rounds into my rifle."

"Depends on the soldier, styer only jams if you dont clean it,m4's hardly jam, cos the steyr is so shit, plastic etc, we are taught to clean vigirously, then when we get the m4, we use the same cleaning techniques, which isnt really required on a non-bullpup metal rifle, therefore it's better for it"

http://members.tripod.com/istiyak_khan/weapons/weapons2.html - Some rates of pistols.
http://www.flashpoint1985.com/cgi-bin/ikonboard311/ikonboard.cgi?s=463f623e118ce526c4f8c8083ff212ee;act=ST;f=69;t=69721;&#top Random old Arma discussion, might be useful.
http://www.abovetopsecret.com/forum/thread186204/pg1 - Why weapons jam.

If you ever wanted to do an animation, this tells you what to do in-case of a jam:

Updated by rye almost 6 years ago


Jam rates of M4, HK416, SCAR and XM8 in this video. Out of 60,000 rounds, "extreme dust test" - most probably the best to simulate Takistan.

XM8 - 127 stoppages.
SCAR - 226 stoppages.
HK416 - 223 stoppages.
M4 - 882 stoppages.

This is out of 60,000 rounds.

The post above this one had malfunctions for weapons and explosives (duds etc) which could be useful to implement as well, especially for the old crappy Takistani grenades. :P

Updated by rye almost 6 years ago

And agreed with post #7 by CarlGustaffa.

The environment should really effect jam rates - so should the magazine and weapon type. And it should link in with temperature of the barrel and how many magazines you go through in a certain period of time - Feature #15343: System of overheating for all the weapons.

Also if you could have a piece of code or training weapon or training magazine of some kind to simulate jams every 10-20 rounds this would be awesome for training missions.

Hope this helps guys.

Updated by rocko almost 6 years ago

  • Target version changed from 1.7 to 1.8

Updated by rye almost 6 years ago

A test in 2003 by US Army soldiers in Afghanistan found the C-Mag unreliable in simulated combat conditions, with frequent failures to feed among the issues.


While loading the magazine there were numerous jams, speed loaders broke, magazines would not accept the full capacity of ammunition.

This is why Magpul have invented 60 and 100 round magazines that look like the stanag design only longer instead of a drum design. Less likely to jam. They are called high-capacity magazines.
& NATO to make:

Updated by Iron_Wardog almost 6 years ago

Those shortcomings led armatac to develop their new 150 round mag (http://www.armatac.com/products.html). Last i heard the marines were looking to use this with the IAR, with encouraging initial results.

Updated by rocko over 5 years ago

  • Category changed from Complex to Integration

Updated by rocko over 5 years ago

  • Target version changed from 1.8 to Planned (Needs Contributors)

Updated by Fisgas over 5 years ago

Now that you guys aren't as busy, maybe you should revisit this feature. I think it would be excellent for immersion and realism.

Updated by rocko about 5 years ago

  • Target version changed from Planned (Needs Contributors) to Arma 3

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