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Discussion Starter · #1 ·
I am fairly new to the AR15, and am interested in commonly available bullet lengths for the .223/5.56 cartridge.
JBM has a pretty good listing for many calibers.
JBM Ballistics bullet lengths
But it doesn't have some of the common off the shelf AR15 ammo.

Here is a few I have sampled, pulling the bullet out of the cartridge (Hornady "hammer" looking device).
0.962" 75g Hornady Frontier 5.56 HPBT Match
0.945" 75g Tula .223 HPBT (steel case, bimetal jacket)

0.918" 62g PMC X-Tac 5.56 M855 (green tip steel penetrator) note: 0.923" on PMC web site
0.900" 62g Norma Tactical 5.56 SS109 (steel penetrator)
0.807" 62g Colt National Match (DoubleTap) .223 (all lead core)

0.813" 55g Hornady .223 Remington V-max (ballistic tip) note: 0.811" JBM web site
0.746" 55g Federal American Eagle 5.56 XM193 note: 0.745" JBM web site
0.749" 55g PMC Bronze .223 note: 0.740" on PMC web site

Can anyone post other common off the shelf bullets?
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Thanks
 

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The Hog Whisperer (Administrator)
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Interesting. Note that the lengths aren't absolute numbers; typically bullets come out of several sets of forming dies during production. So, some variation is expected. HPs in particular don't always have the nose formed exactly the same even coming out of the same die.
 

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Discussion Starter · #3 ·
I forgot to put this Armscor bullet in my list of 62g bullets.
This is from their "Made in USA" Stevensville, MT; not the Armscor Precision made in the Philippines. If there is any difference? I did check the head stamp on the Philippines ammo in the store, and it was the same "A USA". At least right now anyway.

0.918" 62g PMC X-Tac 5.56 M855 (green tip steel penetrator) note: 0.923" on PMC web site
0.900" 62g Norma Tactical 5.56 SS109 (steel penetrator)
0.807" 62g Colt National Match (DoubleTap) .223 (all lead core)
0.810" 62g Armscor USA .223 (all lead core)
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NC rifle--- Great list. Is there any known purpose for the information?
 

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The Shadow (Moderator)
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That's what I was wondering. What difference does the length of the bullet make?
What twist you need for stability.

Many people say something like:
"For a 68gr bullet, you need an X twist".

The weight of the bullet, is a very minor detail that doesn't matter to any typical reloader. It's the length of the projectile, that needs gyroscopic stability.

Cheers
 

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The Hog Whisperer (Administrator)
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JBM stability calculator (or whatever it is called) can answer the length question, very well.

Just keep in mind that production changes over time can alter things a bit.
 

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The Shadow (Moderator)
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Hi NC-rifle. Are you measuring the total bullet length or from the O-give?
CJR50
Given his reference to JBM, and the lengths he has listed; those are total lengths.

Cheers
 

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So you want to measure the length to know if your rifle will stabilize the bullet. Why not
simply get the BC of the box the bullet came in? For what ever reason a good number of people seem to like to make loading ammo a secrete science for which they probably are not even qualified! When I had my 6.5x06 put together I called Hornady asking about the 140grbullet stabilizing in a 1-9 twist, Hornady told me no way. So I called Sierra and asked the same question and they said yes but the 142 gr bullet won't. best shooting bullet in that rifle is the 140gr SMK. First season hunting with that rifle, a 140gr Hornady inter lock did a fine job on a nice cow elk. Killed my first elk with that rifle using a bullet that was not supposed to stabilize. Reloader's take on to much deciding things that maybe they shouldn't do! In many case's it does work out alright in other case's it simply leaves the handloader confused. I went back and looked at the bullet's he was talking about and as I understand it the 62gr bullet will work in a 223 with factory barrel. maybe that wrong and I don't care. I'd have no use for that heavy a bullet in a 223! I'd rather about the same bullet wt in a 243.
 

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The Shadow (Moderator)
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1) So you want to measure the length to know if your rifle will stabilize the bullet. Why not simply get the BC of the box the bullet came in?
2) When I had my 6.5x06 put together I called Hornady asking about the 140grbullet stabilizing in a 1-9 twist, Hornady told me no way. So I called Sierra and asked the same question and they said yes but the 142 gr bullet won't. best shooting bullet in that rifle is the 140gr SMK.
3) I went back and looked at the bullet's he was talking about and as I understand it the 62gr bullet will work in a 223 with factory barrel. maybe that wrong and I don't care. I'd have no use for that heavy a bullet in a 223! I'd rather about the same bullet wt in a 243.
1) Because Stability and BC are not the same thing. As far as the BC is concerned, people classically know a little about the G1. What they rarely care to learn, is that the single G1 number they hold up on a pedestal usually isn't tangible to them. MOST of the time when they are looking at a single G1 for trajectories, they are using it in a cartridge that likely will never appreciably achieve a velocity to be able to achieve that number. They typically are using bullets that are actually more like a G7 projectile, and then get confused why their "expected" trajectories don't match reality.

2) This could likely be for a few reasons. Enviros will change what is or isn't stable, and each bullet(140gr Hornady or 140gr SMK) are different lengths. Since the thread is about a 223, here's a perfect example I posted about years ago. The 75gr Vmax is notably longer than the 77gr SMK. When I would go south and visit friends in AZ, I used to make pretty good money on betting the new agents about shooting milk jugs at distance. Bet them that you can shoot the 77gr and hit the jug at distances, but that they couldn't do that with the lighter 75gr from the same gun. Purely by the numbers, my 9-twist bolt gun would only marginally stabilize the 77gr SMK. But in the hills where we were shooting, they were perfectly stable; the 75gr Vmax were nothing close to stable.

3) The OP does care, clearly. Which 62gr bullet, and what twist a "factory barrel" twist actually is; will give different results. If he wants to go shooting in the winter, and only has a 9-twist barrel. His stability will be marginal, and the BC will be affected because of it.

Cheers
 

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Discussion Starter · #14 · (Edited)
Hi NC-rifle. Are you measuring the total bullet length or from the O-give?
CJR50
That is the total length I measured. I am curious about the various lengths of bullets of the same weight.
For example, the 62gr green tip with steel penetrator is much longer than a 62gr FMJ-BT with all lead core. (steel weighs less than lead, so they put more lead behind the steel penetrator to get the total weight up to 62gr.

It is my understanding that most ogive tools are just comparators, comparing one bullet to the next in the same comparator. My number could be different than another brand tool.

Does anybody have other bullet lengths (or their measure/sample to confirm)?
I was a little surprised the one Norma 62g SS109 was only 0.900" (I was expecting around 0.91") and the X-Tac M855 was 0.918"
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The Shadow (Moderator)
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It looks like you're searching for something that doesn't exist.

Back to what MikeG said earlier:
"The same" bullets are made on any number of different machines, which have different states of wear on them. "The same" brand of bullet will have construction changes over time, like the AMP changes on the HornHead bullets.
This is also shown, by virtue of various lengths listed on the JBM site.

Not all "same weight" bullets are secant ogive construction, or even the run the same number of calibers in their nose profiles.
Which is to say, expect to see a lot of various lengths from bullets of a common weight; especially if you're using cheap calipers.


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Discussion Starter · #16 ·
Not all "same weight" bullets are secant ogive construction, or even the run the same number of calibers in their nose profiles.
Which is to say, expect to see a lot of various lengths from bullets of a common weight; especially if you're using cheap calipers.


Cheers
BINGO ! exactly why I am asking for people's measurements (and many brands don't list length).
Nose shape, core material (lead, copper, steel penetrator), nose shape, polymer tip/FMJ, etc.)
 

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The Hog Whisperer (Administrator)
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It is going to vary over time, so there's an endless amount of data to collect. As an example, Quickload has a database which lists a LOT of bullet lengths..... but, taking a few random things that I have out of the box to compare, they don't always match up exactly. If you get plus or minus ten thousandths from what they are supposed to be, that's reasonably close.

I've toured the plant at Sierra some years ago. It is astonishing how fast those machines spit bullets out! And when they store them in 30-something gallon drums, it's unlikely they were all individually measured.... ;)
 

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If we're compiling data, I for one also consider the following to be of intrest:

1) length from base to the nominal contact point w/the nominal rifling. Current market available measuring tools make this difficult because they are aluminum, depend on the maintenance of a sharp square corner, & are made to be used in less accurate calipers.

2) base to start & finish of the cannalure (if present). Or the base to the intersection of the nose ogive.

Yes, hard to measure, normal tolerances of barrel/chamber/leade & bullet manufacturing tolerances compound the issue, but at least some measurements would help serve to keep us from jamming bullets into the rifling when looking @ new bullets we haven't yet purchased but are considering.

My $ 0.02!
 

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With two Sinclair "Nuts" and a pair of calipers, the bearing surface of the bullet can be measured. With one Nut and a height gauge, all the measurements can be taken.
I prefer shooting them, myself.
 
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The Hog Whisperer (Administrator)
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It would be a Sisyphean task to even try to collect the lengths of all the bullets that are currently on the shelves, from the forming dies currently in use. Then, as soon as something changes, start all over again.

Oh and by the way, should have started on this task at least a hundred years ago ;)

Collect all the data you want, but in the morning, the boulder will be at the bottom of the hill again. Best of luck.....
 
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