4Game

Misfires & Jams, an in-depth analysis

Jamming

Spoiler alert, weapon jamming depends on your weapon's durability.
I couldn't find ANY data about jamming, so I made a formula for calculating your jam chance.

The game only runs a jam check applies if your weapon has one or more of the following attributes.

Your gun has ammo in the magazine
Your weapon does not have a bolt catch
Your weapon does not have a magazine inserted

If those checks succeed, the game generates a random number and checks it against a few variables.
You can use the formula below to calculate your chance of jamming per shot.

30 – 0.295 * Weapon's current durability = Chance in percentage to jam per shot

For example:

A weapon with 100.0 durability will have a 0.5% chance to jam per shot

A weapon with 50.0 durability will have a 15.25% chance to jam per shot

A weapon with 1.0 durability will have a 29.705% chance to jam per shot

Misfires

Misfiring entirely depends on your ammo.
I couldn't find ANY data about misfiring, so I compiled a list of the chances for every(?) ammo type.

Ammo type	Misfire chance
.45 ACP AP	0.03%
.45 ACP HYDRA SHOK	0.03%
.45 ACP LASERMATCH FMJ	0.03%
.45 ACP	0.03%
.45 RIP	0.03%
12.7×108 BZT	0.01%
12.7×108	0.01%
12.7×55 PS12	0.01%
12.7×55 PS12A	0.01%
12.7×55 PS12B	0.01%
12×70 BUCKSHOT 525	0.01%
12×70 BUCKSHOT 65	0.01%
12×70 BUCKSHOT 85	0.01%
12×70 BUCKSHOT	0.01%
12×70 DUAL SABOT SLUG	0.01%
12×70 FLECHETTE	0.01%
12×70 RIP	0.01%
12×70 SLUG 50 BMG	0.01%
12×70 SLUG AP 20	0.01%
12×70 SLUG FTx CUSTOM LITE	0.01%
12×70 SLUG GRIZZLY 40	0.01%
12×70 SLUG HP COPPER	0.01%
12×70 SLUG POLEVA 3	0.01%
12×70 SLUG POLEVA 6U	0.01%
12×70 SLUG SUPERFORMANCE	0.01%
12×70 SLUG	0.01%
20×70 BUCKSHOT 5.6	0.01%
20×70 BUCKSHOT 6.2	0.01%
20×70 BUCKSHOT 7.3	0.01%
20×70 BUCKSHOT	0.01%
20×70 SLUG DEVASTATOR	0.01%
20×70 SLUG POLEVA 3	0.01%
20×70 SLUG POLEVA 6U	0.01%
20×70 SLUG STAR	0.01%
23×75 BARRICADE	0.01%
23×75 SHRAPNEL 10	0.01%
23×75 SHRAPNEL 25	0.01%
23×75 STAR	0.01%
.366 AP	0.01%
.366 TKM EKO	0.01%
.366 TKM FMJ	0.01%
.366 TKM GEKSA	0.01%
40×46 M381	0.01%
40×46 M386	0.01%
40×46 M406	0.01%
40×46 M433	0.01%
40×46 M441	0.01%
40×46 M576	0.01%
40×46 M716	0.01%
4.6×30 ACTION SX	0.01%
4.6×30 AP SX	0.01%
4.6×30 FMJ SX	0.01%
4.6×30 SUBSONIC SX	0.01%
5.45×39 7N39	0.01%
5.45×39 BP	0.01%
5.45×39 BS	0.01%
5.45×39 BT	0.01%
5.45×39 FMJ	0.03%
5.45×39 HP	0.02%
5.45×39 PP	0.01%
5.45×39 PRS	0.01%
5.45×39 PS	0.01%
5.45×39 SP	0.02%
5.45×39 T	0.01%
5.45×39 US	0.01%
5.56×45 55 FMJ	0.01%
5.56×45 55 HP	0.01%
5.56×45 M855	0.01%
5.56×45 M855A1	0.01%
5.56×45 M856	0.01%
5.56×45 M856A1	0.01%
5.56×45 M995	0.01%
5.56×45 MK 255 MOD 0	0.01%
5.56×45 WARMAGE	0.01%
5.7×28 L191	0.01%
5.7×28 R37F	0.01%
5.7×28 R37x	0.01%
5.7×28 SB193	0.01%
5.7×28 SS190	0.01%
5.7×28 SS197SR	0.01%
5.7×28 SS198LF	0.01%
7.62x25TT AKBS	0.03%
7.62x25TT FMJ43	0.05%
7.62x25TT LRN	0.03%
7.62x25TT LRNPC	0.02%
7.62x25TT P GL	0.02%
7.62x25TT PST GZH	0.02%
7.62x25TT T GZH	0.01%
.300 BLACKOUT AP	0.01%
.300 BLACKOUT	0.01%
7.62×39 BP	0.01%
7.62×39 HP	0.01%
7.62×39 PS	0.01%
7.62×39 T45M	0.01%
7.62×39 US	0.01%
7.62×51 BPZ FMJ	0.01%
7.62×51 M61	0.01%
7.62×51 M62	0.01%
7.62×51 M80	0.01%
7.62×51 M993	0.01%
7.62×51 TPZ SP	0.01%
7.62×51 ULTRA NOSLER	0.01%
7.62x54R 7BT1	0.01%
7.62x54R 7N37	0.01%
7.62x54R T46M	0.01%
7.62x54R 7N1	0.01%
7.62x54R LPS GZH	0.01%
7.62x54R SNB	0.01%
86×70 LAPUA AP	0.01%
86×70 LAPUA MAGNUM UPZ	0.01%
86×70 LAPUA MAGNUM	0.01%
86×70 LAPUA TAC x	0.01%
9x18PM BZT GZH	0.02%
9x18PM P GZH	0.02%
9x18PM PBM	0.01%
9x18PM PMM	0.01%
9x18PM PPE GZH	0.01%
9x18PM PPT GZH	0.01%
9x18PM PRS GS	0.01%
9x18PM PS GS PPO	0.01%
9x18PM PSO GZH	0.01%
9x18PM PST GZH	0.02%
9x18PM PSV	0.01%
9x18PM RG028 GZH	0.01%
9x18PM SP7 GZH	0.01%
9x18PM SP8 GZH	0.01%
9×19 7N31	0.03%
9×19 AP 63	0.03%
9×19 GREEN TRACER	0.03%
9×19 LUGER CCI	0.03%
9×19 PSO GZH	0.03%
9×19 PST GZH	0.03%
9×19 QUAKEMAKER	0.03%
9×19 RIP	0.03%
9×21 SP10	0.01%
9×21 SP11	0.01%
9×21 SP12	0.01%
9×21 SP13	0.01%
9×39 BP	0.01%
9×39 SP5	0.01%
9×39 SP6	0.01%
9×39 SPP	0.01%