JM61 (20 mm)

Description

The 20 mm JM61 is a Japanese naval cannon. It is a version of the 20 mm JM61A1 rotary aircraft cannon equipped on Japanese jet fighters.

Vehicles equipped with this weapon

• PG 02

General info

The JM61 has the second-highest rate of fire of any naval weapon, at a whopping 3,000 rounds per minute (RPM). As such, the JM61 can shred through any boat with ease and even dissect larger ships. There is also a modification available to lower the rate of fire to 450 RPM, but the decrease in effectiveness is not worth the extra time of continuous fire.

Available ammunition

The JM61 has a choice of 3 belts: HEI, API-T, and APDS.

• 20 mm HEI belts: HEF-I · API-T · HEF-I · HEF-I · API-T · HEF-I
• API-T: API-T · HEF-I · API-T · API-T · HEF-I · API-T
• 20 mm APDS belts: APDS · APDS · APDS · APDS

Penetration statistics
Belt	Penetration @ 0° Angle of Attack (mm)
	10 m	100 m	500 m	1,000 m	1,500 m	2,000 m
HEI	53	50	41	34	29	25
API-T	53	50	41	34	29	25
APDS	80	74	50	31	19	12

Shell details
Ammunition	Velocity (m/s)	Projectile Mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Explosive Mass (TNT equivalent) (g)	Ricochet
						0%	50%	100%
API-T	1,030	0.15	N/A	N/A	N/A	47°	60°	65°
HEF-I	1,030	0.1	0	0.1	10	79°	80°	81°
APDS	1,128	0.1	N/A	N/A	N/A	75°	78°	80°

Comparison with analogues

• AK-230 - 30 mm CIWS cannon found on the Pr. 206, has a third the rate of fire, but each turret has 2 barrels, meaning that the Pr. 206 effectively fires 4,000 RPM
• 30 mm/54 AK-630 - 30 mm CIWS cannon mounted on the MPK Pr.12412, has an even higher rate of fire than the JM61 at 5,000 RPM, but no access to any armour-piercing rounds

Usage in battles

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Pros and cons

Pros:

• Very high rate of fire
• API-T and APDS belts can cut through most ships it meets

Cons:

• Overheats quickly, continuous fire is not recommended

History

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Media

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See also

• M61 (20 mm)
• M61A1 (20 mm)
• JM61A1 (20 mm)

External links

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• topic on the official game forum;
• other literature.

Japan naval cannons
20 mm	JM61 · Type 98
25 mm	25 mm/60 Type 96
37 mm	Type 4 · Type 11 pattern 1922
40 mm	40 mm/62 Vickers
57 mm	Type 97
75 mm	Type 88 AA
76 mm	3-inch/40 Type 41 · 8 cm/40 3rd Year Type · 8 cm/60 Type 98
100 mm	100/65 mm Type 98 mod A
120 mm	120 mm/45 3rd Year Type · 120 mm/45 10th year type
127 mm	5 inch/40 Type 89 · 127 mm/50 3rd Year Type
140 mm	140 mm/50 3rd Year Type
152 mm	6-inch/45 Type 41 · 15 cm/50 Type 41
155 mm	155 mm/60 3rd Year Type
200 mm	20 cm 3rd year type No.1
203 mm	20 cm/45 Type 41 · 20 cm/50 3rd year type No.2
356 mm	36 cm/45 Type 41
410 mm	410 mm/45 Type 3
	Foreign:
20 mm	20 mm/70 Oerlikon Mk.II (USA/Britain)
40 mm	Bofors L/60 Mark 1 (USA) · Bofors L/60 Mark 2 (USA) · Bofors L/60 Mark 3 (USA)
47 mm	3 pdr QF Hotchkiss (Britain)
76 mm	3-inch Mark 10 (USA) · 3 inch Mk.33 (USA) · 3-inch Mk.34 (USA)
120 mm	4,7-inch/40 Armstrong (Britain)
127 mm	5 inch/38 Mk.12 (USA)
305 mm	12-inch/45 Vickers (Britain) · 12-inch/50 Vickers (Britain)