Gun Characteristics.
Designation 8 cm/60 (3.0") Type 98 (Model 1938)
Ship Class Used On Agano class Planned for the Ibuki class
Date Of Design 1938
Date In Service 1942
Gun Weight 1.30 tons (1.32 mt)
Gun Length oa 188 in. (4.777 m)
Bore Length 179.78 in (4.567 m)
Rifling Length 159 in. (4.037 m)
Grooves (24) 0.040 in deep x 0.241 in (1.02 mm x 6.12 mm)
Lands 0.152 in (3.85 mm)
Twist Uniform RH 1 in 28
Chamber Volume 213.6 in3 (3.5 dm3)
Rate Of Fire (see Note 2) 25 rounds per minute
Notes:1) The semi-automatic rammer was cocked by the recoil forces when the gun fired.2) Once the ready rounds were used up, the firing rate was limited by the shell hoists. These could supply each twin mounting with about 25 rounds per minute, which was about half the theoretical ROF.
.Ammunition.
Type Fixed
Complete Round Weight Type 98 Common HE - 26.5 lbs. (12 kg)
Projectile Types and Weights Type 98 Common HE - 13.2 lbs. (5.99 kg)
Bursting Charge Type 98 Common HE - 0.68 lbs. (0.31 kg)
Projectile Length 12.8 in (32.51 cm) Complete round: 30.04 in (76.9 cm)
Propellant Charge 4.21 lbs. (1.91 kg) C2, C3 and DC
Muzzle Velocity 2,953 to 3,018 fps (900 to 920 mps)
Working Pressure 17.8 to 18.4 tons/in2 (2,800 to 2,900 kg/cm2)
Approximate Barrel Life 600 rounds
Ammunition supply per gun 250 rounds
Note: The sources below differ as to the weight of the propellant charge for these guns. I have chosen to use the weight given in "Naval Weapons of World War Two."
.Range.
Elevation With 13.2 lbs. (5.99 kg) HE Shell
Range @ 45 degrees 14,870 yards (13,600 m)
AA Ceiling @ 90 degrees 29,850 feet (9,100 m)
.Mount / Turret Data.
Designation Twin Mounts Agano (2): Type A
Weight 12.3 tons (12.5 mt)
Elevation -10 / +90 degrees
Elevation Rate 16 degrees per second
Train about -150 / +150 degrees
Train Rate 16 - 18 degrees per second
Gun recoil N/A
Loading Angle Any
Notes:1) Two bucket hoists on the Agano class delivered ammunition to a working chamber on the upper deck abreast the mountings. Supply was 25 rounds per hoist. Shells were passed from the working chamber to the guns by hand.2) The automatic fuze setting apparatus was attached to the breech end of the gun. This was actuated by hand just before the shell was rammed.

Gun Characteristics.
Designation 10 cm/65 (3.9") Type 98 (Model 1938)
Ship Class Used On Akitsuki, Oyodo, Taiho and B-64 classes
Date Of Design 1938
Date In Service 1942
Gun Weight 6,731 lbs. (3,053 kg)
Gun Length oa 265.0 in (6.730 m)
Bore Length 255.9 in (6.500 m)
Rifling Length 221.7 in (5.631 m)
Grooves (32) 0.49 in deep x 0.219 in (1.25 mm x 5.565 mm)
Lands 0.167 in (4.252 mm)
Twist Uniform RH 1 in 28
Chamber Volume 641 in3 (10.5 dm3)
Rate Of Fire 15 - 21 rounds per minute
.Ammunition.
Type Fixed
Weight of Complete Round HE - 61.7 lbs. (28 kg)
Projectile Types and Weights HE - 28.67 lbs. (13 kg)
Bursting Charge 2.1 lbs. (0.95 kg)
Projectile Length 16.1 in (41 cm) Complete Round: 44 in (111.8 cm)
Propellant Charge 13.2 lbs. (6 kg) 30 DC (?) Cartridge - 33 lbs. (15 kg)
Muzzle Velocity 3,281 fps (1,000 mps)
Working Pressure 19.4 tons/in2 (3,050 kg/cm2)
Approximate Barrel Life 350 - 400 rounds
Ammunition stowage per gun about 400 rounds on larger ships Oyodo: 200 rounds Akitsuki: N/A
Note: It is interesting to note that the Japanese apparently never developed incendiary shrapnel, ASW or even illumination rounds for this weapon, implying that it was solely intended for use as an AA gun. Practice shells were provided.
.Range.
Elevation With 28.67 lbs. (13 kg) HE Shell
Range @ 45 degrees 21,325 yards (19,500 m)
AA Ceiling @ 90 degrees 42,651 feet (13,000 m)
Note: Effective surface range is given as 15,310 yards (14,000 m) and effective AA range as 12,030 yards (11,000 m).
.Mount / Turret Data.
Designation Twin Mounts Akitsuki (4), Oyodo (4), Taiho (6) and B-64 (8): Model A
Weight 76,060 lbs. (34,500 kg)
Elevation -10 / +90 degrees
Elevation Rate 16 degrees per second
Train Oyodo, Taiho and B-64: About +/-70 degrees Akitsuki: -150 / +150 degrees
Train Rate 11 - 16 degrees per second
Gun recoil Minimum 16.1 in, nominal 19.3 in, maximum 19.7 in (41 cm, 49 cm and 50 cm)
Loading Angle Any

Gun Characteristics.
Designation 12.7 cm/40 (5") Type 88 (Model 1928) 12.7 cm/40 (5") Type 89 (Model 1929)
Ship Class Used On Type 88: Submarines I.5 and I.6Type 89: Almost all Japanese ships cruiser size and larger, Matsu and Tachibana class escorts
Date Of Design 1928 / 1929
Date In Service 1932
Gun Weight 3.05 tons (3.1 mt)
Gun Length oa 208 in (5.284 m)
Bore Length 200 in (5.080 m)
Rifling Length 175 in (4.450 m)
Grooves (36) 0.060 in deep x 0.261 in (1.52 mm x 6.63 mm)
Lands 0.175 in (4.45 mm)
Twist Uniform RH 1 in 28
Chamber Volume 549 in3 (9.0 dm3)
Rate Of Fire Type 88: 8 rounds per minuteType 89: 14 rounds per minute initially, 8 rounds per minute sustained
.Ammunition.
Type Fixed
Weight of Complete Round Common Type 0 HE - 75.7 lbs. (34.32 kg) Common Type 3 IS - 77.2 lbs. (35 kg) Illum - 75.7 lbs. (34.32 kg)
Projectile Types and Weights (see Note 1) Common Type 0 HE - 51.7 lbs. (23.45 kg) Common Type 3 IS - 50.7 lbs. (23.0 kg) ASW - 46.2 lbs. (20.9 kg) Illum - 51.7 lbs. (23.45 kg)
Bursting Charge Common Type 0 HE - 4.2 lbs. (1.88 kg) ASW - 8.78 lbs. (4.0 kg)
Projectile Length Common Type 0 HE - 17.2 in (43.7 cm) Common Type 3 IS - 17.2 in (43.7 cm) ASW - 17.2 in (43.7 cm)
Complete Round Length 38.2 in (97.1 cm)
Cartridge Case Type, Size and Empty Weight Brass, 127 x 583 mm, about 15.23 lbs. (6.9 kg)
Propellant Charge 8.77 lbs. (3.98 kg) 21 DC Cartridge - 26.3 lbs. (12 kg)
Muzzle Velocity Common Type 0 HE - 2,360 - 2,379 fps (700 - 725 mps) Common Type 3 IS - 2,360 - 2,379 fps (700 - 725 mps) ASW - 820 fps (250 mps) Illum - 2,362 fps (720 mps)
Working Pressure 16 tons/in2 (2,500 kg/cm2)
Approximate Barrel Life 800 - 1500 rounds
Ammunition stowage per gun Yamato class: 300 rounds Cruisers with 4 guns: 250 rounds Cruisers with 8 guns: 200 rounds Others: N/A
Notes:1) IS is my abbreviation for the incendiary shrapnel round (sankaidan) intended for AA use.2) The flat-nosed ASW projectile was issued in 1943 following extensive testing. This is listed in US Naval Technical Mission to Japan report O-19 as being able to penetrate a 9.85 in (25 cm) plate of Ducol Steel (roughly equivalent to USN HTS) at a depth of 26 feet (8 meters). Range for this performance is not given. However, based upon other errors in this document, I would believe this to be an error in metric to english unit conversion and that the actual performance would more likely be 0.985 in (2.5 cm). ASW may have been issued only to escorts.3) Illumination rounds were rated at 680,000 candle power and had a maximum range of 15,910 yards (14,550 m) and an effective range of 8,750 yards (8,000 m).4) Common Type 0 HE was considered to have an 62.7 foot (18.8 m) effective radius of destruction.
.Range.
Elevation With 50.7 lbs. (23 kg) IS Shell
Range @ 45 degrees 16,185 yards (14,800 m)
AA Ceiling @ 75 degrees 30,840 feet (9,400 m)
Elevation With 46.2 lbs. (22.0 kg) ASW Shell
Range @ 40 degrees 4,700 yards (4,300 m)
Note: Minimum range of ASW shell is given as 875 yards (800 m). Ranges less than this tended to ricochet.
.Mount / Turret Data.
Designation(see Notes 1 and 5) Type 88 Single Mounting I.5 (1): A I.6 (1): A mod 1Type 89 Twin Mounts Kongô (4), Fuso (4), Ise (4), Nagato (4), Aoba (2), Furataka (2), Takao (4), Atago (4) and Maya (4): A1 Myôkô (4), Mogami (4), Tone (4), Akashi (2), Ashizuri (2) and Hayasui (2): A1 Mod 1 Kaga (8), Ryûjô (4), Shôkaku (8), Hiryû (6), Shoho (4), Hiyo (6), Ryûhô (ex-Taigei) (4), Shoho (ex-Tsurugizaki) (4), Chiyoda (4), Kaiyo (4), Shinyo (4), Shinano (8), Unryu (6), Hiyo (6), Ryuho (4), Kaiyo (4), Shinyo (4), Shinano (8), Unryu (6), Mizuho (3) and Tsugaru (2): A1 Mod 2 Yamato (6): A1 Mod 3 Matsu (1) and Tachibana (1): B1Type 89 Single Mount Matsu (1) and Tachibana (1): B1 Mod 4
Weight Type 88 A and A mod 1: 8.7 tons (8.8 mt)Type 89: A1: 20 tons (20.3 mt) A1 Mod 1: 24 tons (24.5 mt) A1 Mod 2: about 24 tons (24.5 mt) A1 Mod 3: 28.5 tons (29 mt) B1: N/A B1 Mod 4: N/A
Elevation Type 88: - 7 / +75 degreesType 89: -7 / +90 degrees (one source says -8 / +85 degrees)
Elevation Rate Type 88 Manual operation, only.Type 89 A1 (all): 12 degrees per second B1: 16 degrees per second
Train Amidships Mounts: About -70 / +70 degreesBow and Stern Mounts: About -150 / +150 degrees
Train Rate Type 88 Manual operation, only.Type 89 A1 (all): 6 to 7 degrees per second B1: 16 degrees per second
Gun recoil 17.75 in (45.0 cm)
Loading Angle Any

Gun Characteristics.
Designation 3"/40 (7.62 cm) 3rd Year Type (Model 1914) 8 cm/40 (3") 3rd Year Type (Model 1914) 8 cm/40 (3") 11th Year Type (Model 1922) 8 cm/40 (3") Type 88 (Model 1928)
Ship Class Used On Furutaka and Aoba (as built) Small ships and submarines
Date Of Design 1914, 1922 and 1928
Date In Service 1916, 1926 and 1932
Gun Weight 1,323 lbs. (600 kg)
Gun Length oa 126.1 in. (3.203 m)
Bore Length 120.0 in (3.048 m)
Rifling Length (see Note) All except Model Type IV: 102.7 in. (2.608 m) Model Type IV: 103.2 in (2.623 m)
Grooves Barrel Model Types I and II: (16) 0.39 in deep x 0.366 in (1.00 mm x 9.300 mm) Barrel Model Types III, IV and VII: (24) 0.39 in deep x 0.232 in (1.00 mm x 5.905 mm)
Lands 0.160 in (4.07 mm)
Twist Uniform RH 1 in 28
Chamber Volume 128 in3 (2.1 dm3)
Rate Of Fire 13 to 20 rounds per minute
Note: The Model Type IV barrel had a slightly longer chamber length, hence the difference in rifling length. The Chamber Volume was the same as in the other Model Types.
.Ammunition.
Type Fixed
Weight of Complete Round Common Type 0 HE - 20.4 lbs. (9.25 kg) ASW - N/A
Projectile Types and Weights Common Type 0 HE - 13.2 lbs. (5.99 kg) ASW - 11.7 lbs. (5.3 kg)
Bursting Charge Common Type 0 HE - 1.06 lbs (0.48 kg) ASW - 1.5 lbs. (0.67 kg)
Projectile Length Common Type 0 HE - 11.1 in (28.2 cm) ASW - 11.3 in (28.5 cm)
Propellant Charge Common Type 0 - 2.0 lbs. (0.9 kg) 20 C3 ASW - N/A
Muzzle Velocity Common - 2,231 to 2,247 fps (680 to 685 mps) ASW - 820 fps (250 mps)
Working Pressure 14.5 tons/in2 (2,250 kg/cm2)
Approximate Barrel Life 1,200 - 2,000 rounds
Ammunition stowage per gun N/A
Note: The flat-nosed ASW projectile was issued in 1943 following extensive testing. This is listed in US Naval Technical Mission to Japan report O-19 as being able to penetrate a 4.53 in (11.5 cm) plate of Ducol Steel (roughly equivalent to USN HTS) at a depth of 26 feet (8 meters). However, based upon other errors in this document, I would believe this to be an error in metric to english unit conversion and that the actual performance would more likely be 0.453 in (1.15 cm). Range for this performance is not given.
.Range.
Elevation With 13.2 lbs. (5.99 kg) HE Shell
Range @ 45 degrees 11,800 yards (10,800 m)
AA Ceiling @ 75 degrees 23,600 feet (7,200 m)
Elevation With 11.7 lbs. (5.3 kg) ASW Shell
Range @ 40 degrees 3,500 yards (3,200 m)
Note: Minimum range of ASW shell is given as 766 yards (700 m). Ranges less than this tended to ricochet.
.Mount / Turret Data.
Designation Single mounts
Weight about 3.3 tons (3.35 mt)
Elevation -7 / +75 degrees
Elevation Rate Manually operated, only 7 - 10 degrees per second
Train 360 degrees
Train Rate Manually operated, only 10 - 11 degrees per second
Gun recoil N/A
.

4种炮具体数据对比如下
炮口初速，76L40，680-685m/s，76L60，900m/s，100L65，1000m/s，127L40，720-725m/s，
弹重，76L40，5.99kg，76L60，5,99kg，100L65，13kg，127L40，23kg
射程，76L40，10800m/45°，76L60，13600m/45°，100L65，19500m/45°，127L40，14800m/45°
射高，76L40，7200m/75°，76L60，9100m/90°，100L65，13000m/90°，127L40，9400m/75°
射速，76L40，13-20RPM，76L60，25RPM，100L65，15-21RPM，127L40，8-14RPM
旋转速度，76L40，7-10DPS，76L60，16-18DPS，100L65，16DPS，127L40，A1，6-7DPS，B1，16DPS。
炮重/炮塔重，76L40，单装3.3mt，76L60，联装12.5mt，100L65，联装34.5mt，127L40，20.3/24.5/29mt。
身管寿命，76L60，600发，100L65，350-400发，76L40和127L40未知，不过肯定比76L60高。

对比一下4种高炮，
射程射高，76L60性能数据13600/9100米比起来100L65的19500/13000米差了不少，但是相比127L40的14800/9400米差的不多，更是完爆老式76L40的10800/7200米。
弹重不用说，76L60的6kg没有资格和100L65的13kg和127L40的23kg弹重比。
炮口初速，76L60的900m/s虽然弱于100L65的1000m/s，但是远高于76L40和127L40的680和720m/s。
但是接着就都是76L60的亮点了。
他的射速是4种炮里面最快的，25RPM比100L65的15-21RPM都快，更完爆127L40的8-14RPM
他的旋转速度4种炮里面最快的，16-18DPS比100L65的11-16DPS和127L40B1炮塔的16DPS都略快，更远大于127L40的A1炮塔的6-7DPS和76L40的7-10DPS。
他的重量相比100L65和127L40很轻，联装炮12.5吨只有100L65的34.5吨的三分之一多，127L40的20.3/24.5/29吨的三分之二或者少一半。
他的身管寿命600发长于100L65的350-400发。

所以说这种高炮作为鬼子CL的副炮或者防空巡洋舰的高炮还是很合适的。
毕竟海上目标，飞行高度都不会太高，反而射速旋转速度是关键。炮重轻还可以多布置不少火炮，增加火力密度，毕竟没有VT引信，大口径中口径高射炮都是听响而已，最多起到弹幕的作用，火炮数量和火力密度比射程射高更重要。
所以部分用76L60替换127L40甚至100L65，未必是坏的选择。

首先是大和级战列舰，因为有12门155副炮了，所以对于对海火力要求不大，没有必要安装127L40作为高射炮，还不如直接用76L60合适。
12门127L40的重量，上24-36门76L60足够了，这个高射炮的火力密度肯定超过12门127L40甚至24门127L40的火力密度。

其次是阿贺野级轻巡洋舰，其实以其吨位和舰体尺寸，上6门155L60和8门76L60没啥问题，而不是历史上的6门152和4门76L60，后来的阿贺野改，加长了10米舰体和增加了1200吨排水量，就上了8门152和8门76L60，要知道阿贺野改的主机功率可是从10万HP增加到了15.2万HP，动力系统的增重就占了相当部分，所以最初的阿贺野副炮采用8门76L60肯定没有问题。
阿贺野如果说是6门155L60和8门76L60，性能数据会比历史上的6门152和4门76L60会强不少。也不那么废柴了。

还有防空舰，历史上倭国用2700吨舰体搭载8门100L65的秋月其实是高不成低不就的表现，还不如用5500吨CL改装防空舰，不建造秋月，留着主机建造甲驱。甲驱主炮从127L50平射炮改为127L40高平两用炮就行了。
但是如果需要，完全可以在甲驱舰体上直接改装防空驱逐舰，原先的6门127L40高平两用炮直接改成12门76L60高射炮。

鬼子不建造秋月级，防空舰或者说防空巡洋舰用CL舰体改装或者改建。
第一代防空巡洋舰用5500吨CL改建，武备是12门127L40。
第二代防空巡洋舰用6652吨的阿贺野改建，武备是12门100L65。
但是个人以为都可以增加一些76L60替代部分大口径高射炮。
5500吨改造防空CL，可以变为8门127L40，8-12门76L60
6652吨阿贺野改防空CL，可以变为8门100L65，8-12门76L60
这样防空火力密度也可以提高一些。

总之一句话，76L60绝对不是很多人嘴里的废柴，个人以为反而是鬼子一种不错的高炮，在鬼子没有量产37-40机关炮，没有VT引信的前提下，反而是最适合鬼子的一种舰载高射炮。
如果产能跟得上，不是生产28而是生产2800门，作为127L40的替代品和100L65的补充，还是能够发挥很多作用的。起码在大和级战列舰上，在阿贺野级轻巡洋舰上，在防空巡洋舰和驱逐舰上，都可以发挥很大的作用。

8厘炮的性能并不弱
不大规模列装的原因是造价
此物造价高得离谱，比98式10厘炮便宜不了太多。

这玩意实质就是bofors75mml60高射炮的日本仿制版本