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Posted: 2/1/2012 7:50:17 PM EDT
[#1]
Bore Diameter and Groove Diameter.
Two different things. |
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Posted: 2/1/2012 7:53:21 PM EDT
[#2]
Quoted:
Bore Diameter and Groove Diameter. Two different things. Ahhhh. I see 
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Posted: 2/1/2012 7:54:13 PM EDT
[#3]
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Posted: 2/1/2012 8:06:33 PM EDT
[#4]
I know all of that but I was just crunching numbers and .223 equals 5.6642 |
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Posted: 2/1/2012 8:10:06 PM EDT
[#5]
Quoted: Quoted: Bore Diameter and Groove Diameter. Two different things. Ahhhh. I see Dude, 5.56mm and 7.62mm is the Bore Diameter. 0.224" and 0.308" is the Groove Diameter. Just how drunk are you? |
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Posted: 2/1/2012 8:18:47 PM EDT
[#6]
Enuff 2 post dunk and stup0id
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Posted: 2/1/2012 8:23:14 PM EDT
[#7]
actually i am not drunk but i don't know either, someone care to elaborate a bit more? thanks
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Posted: 2/1/2012 8:27:14 PM EDT
[#8]
Quoted: actually i am not drunk but i don't know either, someone care to elaborate a bit more? thanks The groove diameter is the diameter of the bullet. The bore diameter subtracts the rifling depth. Example: 7.62mm = 0.300" Bullet Diameter = 0.308" The difference means that the rifling depth is ~0.004" 5.56mm = 0.219" Bullet Diameter = 0.224" The difference means that the rifling depth is ~0.0025" |
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Posted: 2/1/2012 8:30:00 PM EDT
[#9]
5.56mm = .223", 7.62mm = .308" It's a math thing
The reverse is not true |
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Posted: 2/1/2012 9:05:21 PM EDT
[#10]
Quoted:
Quoted:
actually i am not drunk but i don't know either, someone care to elaborate a bit more? thanks The groove diameter is the diameter of the bullet. The bore diameter subtracts the rifling depth. Example: 7.62mm = 0.300" Bullet Diameter = 0.308" The difference means that the rifling depth is ~0.004" 5.56mm = 0.219" Bullet Diameter = 0.224" The difference means that the rifling depth is ~0.0025" thanks now it's quite clear but how about .223? it was designed to shoot in .223 bore? but also can be fired in 5.56 is that right? |
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Posted: 2/1/2012 9:09:54 PM EDT
[#11]
Quoted: thanks now it's quite clear but how about .223? it was designed to shoot in .223 bore? but also can be fired in 5.56 is that right? The original name of the .223 Remington was the .222 Remington Special, which they though would create confusion with the .222 Remington, which was introduced in 1950. In 1959 they changed it to .223 Remington. |
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Posted: 2/1/2012 9:22:35 PM EDT
[#12]
when a cartridge is designed, obviously bullet diameter is specified, does the bore diameter is also fixed (part of the spec)? or it can be shot in various bore diameter?
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Posted: 2/1/2012 9:25:46 PM EDT
[#13]
Before WWII .22 center fire groove diameters varied from one maker to another. Rifles, barrels, ammunition and bullets could be had in different diameters of .22 cal. There was no industry standard as so to speak and wild catting was all the rage for decades to come.
By the end of the 1950's .224 became the dominant bullet/groove diameter but there were still makers out there producing .223 groove well into the 1960's. No idea about European makers. Hornady makes bullets for the hand loader in .222, .223, .224 and .227 diameter. Sierra make them in .223 and .224 |
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Posted: 2/1/2012 9:29:05 PM EDT
[#14]
deleted double post,,,,,don't know how I did that.
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Posted: 2/1/2012 9:53:37 PM EDT
[#15]
Quoted: when a cartridge is designed, obviously bullet diameter is specified, does the bore diameter is also fixed (part of the spec)? or it can be shot in various bore diameter? Essentially, the bore diameter is fixed because the rifling depth is fixed. .22's have ~0.005" to 0.006" 6mm's and .25's have ~0.006" to 0.007" 6.5mm's have ~0.007" .27's have ~0.007" to 0.008" 7mm's, 7.62mm's have ~0.008" |
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Posted: 2/2/2012 3:28:23 PM EDT
[#16]
Quoted:
Quoted:
when a cartridge is designed, obviously bullet diameter is specified, does the bore diameter is also fixed (part of the spec)? or it can be shot in various bore diameter? Essentially, the bore diameter is fixed because the rifling depth is fixed. .22's have ~0.005" to 0.006" 6mm's and .25's have ~0.006" to 0.007" 6.5mm's have ~0.007" .27's have ~0.007" to 0.008" 7mm's, 7.62mm's have ~0.008" so rifling depth is in the spec? i am just curious if one can shoot a round in barrels with slightly different bore diameters |
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Posted: 2/2/2012 3:36:36 PM EDT
[#17]
Quoted: so rifling depth is in the spec? i am just curious if one can shoot a round in barrels with slightly different bore diameters You can only shoot a round that the firearm is chamber for, or that can headspace in the chamber safely (eg, .38 Special in a .357 Magnum chamber). Are you asking if you can handload bullets of different diameters in a cartridge (eg, using 0.355" bullets in a 0.357" barrel, or 0.223" bullets in a 0.224" barrel)? |
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Posted: 2/2/2012 3:52:07 PM EDT
[#18]
Topic Moved
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Posted: 2/2/2012 5:17:36 PM EDT
[#19]
Quoted:
Quoted:
actually i am not drunk but i don't know either, someone care to elaborate a bit more? thanks The groove diameter is the diameter of the bullet. The bore diameter subtracts the rifling depth. Example: 7.62mm = 0.300" Bullet Diameter = 0.308" The difference means that the rifling depth is ~0.004" 5.56mm = 0.219" Bullet Diameter = 0.224" The difference means that the rifling depth is ~0.0025" Sorry, but 7.62 does not always equal .308" bullet diameter. 7.62X54R measures .311". 7.62X39 also is a .311" bullet. 7.62X25 is a .309" bullet. 7.62X45 is a .304" bullet. 7.62X51/.308, 7.5X55, and 30-'06 are .308" bullets. Bore is .300" as stated but groove diameter is .314" on a Mosin Nagant chambered for 7.62X54R. The rifling depth is therefore -.007". There is a clearance of .0015" between the bullet and the bottom of the rifling. Running a .308 in the Mosin Nagant doubles the clearance over the stock 7.62X54R round with a resulting reduction in pressure. |
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Posted: 2/2/2012 5:55:11 PM EDT
[#20]
Quoted: Quoted: Quoted: actually i am not drunk but i don't know either, someone care to elaborate a bit more? thanks The groove diameter is the diameter of the bullet. The bore diameter subtracts the rifling depth. Example: 7.62mm = 0.300" Bullet Diameter = 0.308" The difference means that the rifling depth is ~0.004" 5.56mm = 0.219" Bullet Diameter = 0.224" The difference means that the rifling depth is ~0.0025" Sorry, but 7.62 does not always equal .308" bullet diameter. 7.62X54R measures .311". 7.62X39 also is a .311" bullet. 7.62X25 is a .309" bullet. 7.62X45 is a .304" bullet. 7.62X51/.308, 7.5X55, and 30-'06 are .308" bullets. Bore is .300" as stated but groove diameter is .314" on a Mosin Nagant chambered for 7.62X54R. The rifling depth is therefore -.007". There is a clearance of .0015" between the bullet and the bottom of the rifling. Running a .308 in the Mosin Nagant doubles the clearance over the stock 7.62X54R round with a resulting reduction in pressure. And running 0.310" bullets will cause an increase in pressure. M1891's run from 0.3095 through 0.315". You are bringing up a peasant rifle and other minutia. You also forgot the 7.92x57 and 0.318" vs. 0.323" bores. |
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Posted: 2/2/2012 6:22:17 PM EDT
[#21]
is rifling measured in depth or the height? rifling is engraved on the bullets i shoot. so the bore is the big part of the tube and the rifling is the little part of the tube. nevermind, i'm drinking with the OP....
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Posted: 2/2/2012 9:11:15 PM EDT
[#22]
Quoted:
Quoted:
so rifling depth is in the spec? i am just curious if one can shoot a round in barrels with slightly different bore diameters You can only shoot a round that the firearm is chamber for, or that can headspace in the chamber safely (eg, .38 Special in a .357 Magnum chamber). Are you asking if you can handload bullets of different diameters in a cartridge (eg, using 0.355" bullets in a 0.357" barrel, or 0.223" bullets in a 0.224" barrel)? no i am just curious when a cartridge is designed, whether the rifling depth is strictly specified for it to be shot properly. for example 5.56 and .223 and .22lr all have same bullet diameter, when they were designed, the rifling depths are specified happened to be the same? since they all can be shot in ar-15 bore (.22lr with the kit) also .223 round, does the ".223" have any real meaning/dimension or just a name |
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Posted: 2/3/2012 6:52:08 AM EDT
[#23]
Quoted: Quoted: Quoted: so rifling depth is in the spec? i am just curious if one can shoot a round in barrels with slightly different bore diameters You can only shoot a round that the firearm is chamber for, or that can headspace in the chamber safely (eg, .38 Special in a .357 Magnum chamber). Are you asking if you can handload bullets of different diameters in a cartridge (eg, using 0.355" bullets in a 0.357" barrel, or 0.223" bullets in a 0.224" barrel)? no i am just curious when a cartridge is designed, whether the rifling depth is strictly specified for it to be shot properly. for example 5.56 and .223 and .22lr all have same bullet diameter, when they were designed, the rifling depths are specified happened to be the same? since they all can be shot in ar-15 bore (.22lr with the kit) also .223 round, does the ".223" have any real meaning/dimension or just a name A true .22 Short/Long/Long Rifle is 0.222". They are 19th century rounds. Much of this was trial and error before the turn of the last century. They work well enough. The name .223 Remington means nothing. Remington named it that in 1959 because the original name was the .222 Remington Special. The original name of the .222 Remington Magnum was the .224 Springfield. There is little commonality between the caliber of the barrel, or the name of the round. You just need to memorize them. |
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Posted: 2/3/2012 7:41:17 AM EDT
[#24]
thanks RedFalconBill
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