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Posted: 10/14/2009 4:43:22 AM EDT
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Hey guys, I reloaded my first couple of rounds yesterday (.223)
and I noticed i had some inconsistent COL. Most were right about where i wanted but the biggest difference i had was 2.220 - 2.240 That a pretty big difference. Is this because of inconsistent trimming or something else? Thanks |
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its probably the difference in bullet manufacturing. i think the die seats off the ogive (?) i think thats the spelling. so when you measure end to end they read different. i am sure others can give more detail. Exactly. The Bullet seating die's seat the bullet from the ogive, the overall length will vary, some bullets more than others. Shouln't make much of a different for plinking, if you were making match ammo you would buy match grade bullets and measure every single bullet for consistancy. Does anyone know what the SAMMI spec is for the ogive measurement for .223? I have often wondered that... I don't recall reading it anywhere in my reloading books. Thanks, -Masta |
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You could just weigh them since diameter is EXTREMELY consistent, even on cheaper bullets. The extra weight would tell you that the bullet is longer since diamater and density of material remains constant. How does that equate to length ? 
I could have one round that is 2.26" long at 75 grains and another at 2.40" long, also at 75 grains (ie. Hornady A-max vs. Hornady HPBT Match) You should read through Ammo Oracle. Also read your reloading manuals....you do have them, don't you ? 
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its probably the difference in bullet manufacturing. i think the die seats off the ogive (?) i think thats the spelling. so when you measure end to end they read different. i am sure others can give more detail. Exactly. The Bullet seating die's seat the bullet from the ogive, the overall length will vary, some bullets more than others. Shouln't make much of a different for plinking, if you were making match ammo you would buy match grade bullets and measure every single bullet for consistancy. Does anyone know what the SAMMI spec is for the ogive measurement for .223? I have often wondered that... I don't recall reading it anywhere in my reloading books. Thanks, -Masta There is no SAAMI spec for bullet shape. Get a jig for you caliper that measures off the ogive. |
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its probably the difference in bullet manufacturing. i think the die seats off the ogive (?) i think thats the spelling. so when you measure end to end they read different. i am sure others can give more detail. Exactly. The Bullet seating die's seat the bullet from the ogive, the overall length will vary, some bullets more than others. Shouln't make much of a different for plinking, if you were making match ammo you would buy match grade bullets and measure every single bullet for consistancy. Does anyone know what the SAMMI spec is for the ogive measurement for .223? I have often wondered that... I don't recall reading it anywhere in my reloading books. Thanks, -Masta There is no SAAMI spec for bullet shape. Get a jig for you caliper that measures off the ogive. Not for bullet shape, there is a SAMMI spec for OAL. I have a Hornady Bullet Comparator set to measure ogive, but I can measure ogive all day long and it doesn't tell me anything because I don't have a spec for what the Ogive measurement should be.. So i'm looking for a spec for the ogive measurment from bottom of case to ogive of the bullet. If there is one. If there isn't one I don't know what the purpos of even having a Bullet Comparator. -Masta |
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You could just weigh them since diameter is EXTREMELY consistent, even on cheaper bullets. The extra weight would tell you that the bullet is longer since diamater and density of material remains constant. How does that equate to length ?
I could have one round that is 2.26" long at 75 grains and another at 2.40" long, also at 75 grains (ie. Hornady A-max vs. Hornady HPBT Match) You should read through Ammo Oracle. Also read your reloading manuals....you do have them, don't you ? Indeed I do. I was theorizing out loud I suppose. If you have a match bullet that is fairly consistent in shape, and it will be consistent diameter, then a heavier bullet (of the same design/mfg/shape) would have to be longer, no? Oh, and have read the AO several times and ordered a few more specialty manuals. |
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So i'm looking for a spec for the ogive measurment from bottom of case to ogive of the bullet. If there is one. If there isn't one I don't know what the purpos of even having a Bullet Comparator. -Masta For .223, base to ogive is not important. Most important for accuracy is the datum to ogive measurement. This must be determined for each rifle barrel. If you are shooting from the magazine then the OAL (base to meplat) is important for function. There are tools to measure base to ogive and base to datum. A little math gives datum to ogive. A bullet comparator gives the opportunity to sort bullets for consistency. |
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You could just weigh them since diameter is EXTREMELY consistent, even on cheaper bullets. The extra weight would tell you that the bullet is longer since diamater and density of material remains constant. How does that equate to length ?
I could have one round that is 2.26" long at 75 grains and another at 2.40" long, also at 75 grains (ie. Hornady A-max vs. Hornady HPBT Match) You should read through Ammo Oracle. Also read your reloading manuals....you do have them, don't you ? Indeed I do. I was theorizing out loud I suppose. If you have a match bullet that is fairly consistent in shape, and it will be consistent diameter, then a heavier bullet (of the same design/mfg/shape) would have to be longer, no? Oh, and have read the AO several times and ordered a few more specialty manuals. You are correct in your theory Sam. Just wanted to point out that the OP was concerned with COL. |
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So i'm looking for a spec for the ogive measurment from bottom of case to ogive of the bullet. If there is one. If there isn't one I don't know what the purpos of even having a Bullet Comparator. -Masta For .223, base to ogive is not important. Most important for accuracy is the datum to ogive measurement. This must be determined for each rifle barrel. If you are shooting from the magazine then the OAL (base to meplat) is important for function. There are tools to measure base to ogive and base to datum. A little math gives datum to ogive. A bullet comparator gives the opportunity to sort bullets for consistency. ok, could you dumb that down for us simple folk? -Masta |
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So i'm looking for a spec for the ogive measurment from bottom of case to ogive of the bullet. If there is one. If there isn't one I don't know what the purpos of even having a Bullet Comparator. -Masta For .223, base to ogive is not important. Most important for accuracy is the datum to ogive measurement. This must be determined for each rifle barrel. If you are shooting from the magazine then the OAL (base to meplat) is important for function. There are tools to measure base to ogive and base to datum. A little math gives datum to ogive. A bullet comparator gives the opportunity to sort bullets for consistency. ok, could you dumb that down for us simple folk? -Masta The cartridge references to the rifle chamber on the datum which is on the shoulder of the brass. The bullet touches the rifling at its ogive. The datum to ogive distance sets the distance the bullet will jump (or not jump) from the case to the rifling. This distance is experimentally determined for each barrel to achieve optimum accuracy. Meplat is the tip of the bullet. The distance from the bullet's ogive to its meplat can vary changing the cartridge OAL because the bullet is seated in the die using a point that is approximately at its ogive. Normally for accuracy this variation in OAL is relatively unimportant. More important is the bullet jump distance which is set by the datum to ogive distance. The cartridge base to meplat distance (OAL) is important when firing from a magazine as too long a distance can cause malfunction. This means that when firing from a magazine you have set OAL and therefore have lost control of the bullet jump distance which may or may not be important for accuracy in a specific rifle. |
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The location and shape of the tip from one bullet to the next has virtually no affect on where a bullet goes. You can maul the tip with a pair of pliers and it's still going to land the same place on the target. Even match bullets will have a fairly decent The seating die doesn't press on the tip––it's pushing somewhere further down on the ogive, but not quite where the rifling first meets the lands. This will give you bullet jump which is pretty consistant (and that's what we want)––probably under 0.002-0.003". Basically, you need to be concerned with it only such that you're not going to end up with one round being too long for the magazine. |
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Hey guys, I reloaded my first couple of rounds yesterday (.223) and I noticed i had some inconsistent COL. Most were right about where i wanted but the biggest difference i had was 1.25 - 1.40. That a pretty big difference. Is this because of inconsistent trimming or something else? Thanks Is that correct? If so, you have a far larger problem than the normal variation in the length of target bullets. Don't mangle the tips of bullets with pliers, either. They won't fly right, no matter the advice above. One of the little details an accurate bullet relies on for accuracy is that the mass of the bullet be distributed around its centerline with precise uniformity. |
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Maybe I'm oversimplifying, but have you looked at how consistently you work your press? If its progressive and you start going fast, I've found COAL varies more. If I go slower and focus on making the pulls with the same speed and 'oomph' then it stays more consistent.
Make sure you fully bottom your press and don't sometimes just 'tap' then end of the stroke. |
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You could just weigh them since diameter is EXTREMELY consistent, even on cheaper bullets. The extra weight would tell you that the bullet is longer since diamater and density of material remains constant. How does that equate to length ?
I could have one round that is 2.26" long at 75 grains and another at 2.40" long, also at 75 grains (ie. Hornady A-max vs. Hornady HPBT Match) You should read through Ammo Oracle. Also read your reloading manuals....you do have them, don't you ? Indeed I do. I was theorizing out loud I suppose. If you have a match bullet that is fairly consistent in shape, and it will be consistent diameter, then a heavier bullet (of the same design/mfg/shape) would have to be longer, no? Oh, and have read the AO several times and ordered a few more specialty manuals. I would argue that the variation could also be caused by the density of the lead or impurities. That would no necessarily change the volume of the bullet |
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Hey guys, I reloaded my first couple of rounds yesterday (.223) and I noticed i had some inconsistent COL. Most were right about where i wanted but the biggest difference i had was 1.25 - 1.40. That a pretty big difference. Is this because of inconsistent trimming or something else? Thanks Is that correct? If so, you have a far larger problem than the normal variation in the length of target bullets. Don't mangle the tips of bullets with pliers, either. They won't fly right, no matter the advice above. One of the little details an accurate bullet relies on for accuracy is that the mass of the bullet be distributed around its centerline with precise uniformity. Yeah as a matter of fact that is wrong. should be 2.25 - 2.40 woops. That was the most extreme difference i found, most were at about 2.23. I was more worried about the COL being two small causing overpressure should this be a major concern? or is the differenced mentioned not significate enought to cause that type of problem. This is just plinking ammo not too worried about accuracy. |
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its probably the difference in bullet manufacturing. i think the die seats off the ogive (?) i think thats the spelling. so when you measure end to end they read different. i am sure others can give more detail. Exactly. The Bullet seating die's seat the bullet from the ogive, the overall length will vary, some bullets more than others. Shouln't make much of a different for plinking, if you were making match ammo you would buy match grade bullets and measure every single bullet for consistancy. Does anyone know what the SAMMI spec is for the ogive measurement for .223? I have often wondered that... I don't recall reading it anywhere in my reloading books. Thanks, -Masta There is no SAAMI spec for bullet shape. Get a jig for you caliper that measures off the ogive. Not for bullet shape, there is a SAMMI spec for OAL. I have a Hornady Bullet Comparator set to measure ogive, but I can measure ogive all day long and it doesn't tell me anything because I don't have a spec for what the Ogive measurement should be.. So i'm looking for a spec for the ogive measurment from bottom of case to ogive of the bullet. If there is one. If there isn't one I don't know what the purpos of even having a Bullet Comparator. -Masta The bullet comparator can be used to reliably measure bullet seating depth without having bullet length variation interfere. If you measure the barrel (Hornady has one tool) to find the shoulder to rifling, you can then control the jump of the bullet from the case to the rifling. A comparator allows you to make an accurate measurement to control this jump. COL standards are normally just for magazine fit. |
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Hey guys, I reloaded my first couple of rounds yesterday (.223) and I noticed i had some inconsistent COL. Most were right about where i wanted but the biggest difference i had was 1.25 - 1.40. That a pretty big difference. Is this because of inconsistent trimming or something else? Thanks Is that correct? If so, you have a far larger problem than the normal variation in the length of target bullets. Don't mangle the tips of bullets with pliers, either. They won't fly right, no matter the advice above. One of the little details an accurate bullet relies on for accuracy is that the mass of the bullet be distributed around its centerline with precise uniformity. Yeah as a matter of fact that is wrong. should be 2.25 - 2.40 woops. That was the most extreme difference i found, most were at about 2.23. I was more worried about the COL being two small causing overpressure should this be a major concern? or is the differenced mentioned not significate enought to cause that type of problem. This is just plinking ammo not too worried about accuracy. That's screwed up, too, it's 0.15 inches difference in the length. I wonder if you're misreading the caliper or loading different bullets without mentioning that detail. |
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For plinking ammo that oal variation will not matter. All of the ogive discussion is great for competition shooters. I used to worry about oal variances for my squirrel shooting loads. Then I tested the accuracy of the loads with and without tight variances. I could not document any difference when variance was between 2.243 and 2.255. What I did find that all of the rounds loaded with one lot # of 60gr vmax's were very variable. I bought 500 of a new lot # and my variences dropped to < .02".
Loading too short by way of coal variance will only be an issue if you are pushing max pressure. Since most loads are built @ 223 pressures, assuming you have a 5.56 or wylde chamber, I don't think you will have any issues. |
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His reported COAL varies from 2.25 to 2.40; unless the bullet is a 75 grain AMAX or one of the 80 grain target bullets, the other choices can't be seated out that far, mostly because they'll fall out of the case.
So, it matters. ETA: Some of y'all need to read a little closer (I'm guilty of the same thing sometimes) - the COAL range reported is way outside the normal range of 2.21 to 2.26 inches, unless heavy target bullets are being loaded. |
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Plain and simple - it is the bullets. I use cheaper Winchester 55 FMJ bullets for blasting ammo and the COL varies as much as you described. It's normal with cheaper bullets. More expensive bullets will be more consistent. It doesn't matter as long as your cartridges fit the magazine.
It is frustrating but no big deal. |
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His reported COAL varies from 2.25 to 2.40; unless the bullet is a 75 grain AMAX or one of the 80 grain target bullets, the other choices can't be seated out that far, mostly because they'll fall out of the case. So, it matters. ETA: Some of y'all need to read a little closer (I'm guilty of the same thing sometimes) - the COAL range reported is way outside the normal range of 2.21 to 2.26 inches, unless heavy target bullets are being loaded. I was wrong again 
Was trying to remember off the top of my head but was obviously failing miserably. So the deviation that I am actually getting is 2.220 - 2.240 |
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His reported COAL varies from 2.25 to 2.40; unless the bullet is a 75 grain AMAX or one of the 80 grain target bullets, the other choices can't be seated out that far, mostly because they'll fall out of the case. So, it matters. ETA: Some of y'all need to read a little closer (I'm guilty of the same thing sometimes) - the COAL range reported is way outside the normal range of 2.21 to 2.26 inches, unless heavy target bullets are being loaded. I was wrong again
Was trying to remember off the top of my head but was obviously failing miserably. So the deviation that I am actually getting is 2.220 - 2.240 Now we're getting somewhere. It's the bullets, and you've encountered a common problem. You'll find good boxed hunting bullets will have very uniform lengths, and generally all of the bullets from a single box of HPBT match bullets will be closer than the mixture I buy. |
| I try to be extremely consistent with the press handle when seating bullets but I always end up with a little variation in OAL. It's usually only about .002-.003" or so. I did notice a few 6.8 Nosler Accubonds I loaded the other day varied by .005", and the ones that varied by that much were .005" too long. That may not be much but it caught my attention. |
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His reported COAL varies from 2.25 to 2.40; unless the bullet is a 75 grain AMAX or one of the 80 grain target bullets, the other choices can't be seated out that far, mostly because they'll fall out of the case. So, it matters. ETA: Some of y'all need to read a little closer (I'm guilty of the same thing sometimes) - the COAL range reported is way outside the normal range of 2.21 to 2.26 inches, unless heavy target bullets are being loaded. Good point. You know what they say about assumptions. I had assumed he ment 2.240, my bad. |
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His reported COAL varies from 2.25 to 2.40; unless the bullet is a 75 grain AMAX or one of the 80 grain target bullets, the other choices can't be seated out that far, mostly because they'll fall out of the case. So, it matters. ETA: Some of y'all need to read a little closer (I'm guilty of the same thing sometimes) - the COAL range reported is way outside the normal range of 2.21 to 2.26 inches, unless heavy target bullets are being loaded. Good point. You know what they say about assumptions. I had assumed he ment 2.240, my bad. In this case you assumed correct, I just messed up my numbers |
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