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Old October 30, 2011, 01:49 AM   #1
bwood1800
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Bullet C.O.L.

This might be a stupid question, but here goes.
I just bought some new Hornady 154gr SST to shoot out of my 7mag this year for hunting, so this is my first time reloading these bullets. Well the bullets come with like a belt around them where you're supposed to have it seated to (you all probably know what this is called..). Anyway, I know the Maximum C.O.L. is 3.29 inches, and right now I have it seated at just about that and it still isn't seated down far enough to reach the belt in the bullet. So my question is: Should I just leave it like it is right now at 3.29" or should I just seat it down far enough to where the case is just touching the bottom of the belt in the bullet? I don't know if seating it down farther would matter all that much or not considering the increase of pressure. I seated one down to the belt in the bullet and that makes it have a C.O.L. of 3.245".
In case you need to know. I have cci 250 primers, remington brass, and 61.0 grains of H4831SC. Also I generally crimp my bullets so should I still do it even with the belt or would that grab ahold of the bullet more.


the first picture is how its seated at 3.29"
the second picture is when its at 3.245". Is that right where I want it?
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Old October 30, 2011, 02:59 AM   #2
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Good morning
That belt is the "crimp groove" . It is of little concern to me at firsts. More important is if your present COL will cycle though the magazine and chamber without jamming into the rifling.
Generally what I would do with a new bulet is first see how long I can load that bullet (COL) in a dummy cartrige before it touches the rifling then back off .005. Then try that length in the magazine and see if it cycles through the magazine. Single shots are so much easier of course.
On a hard kicker that is what that belt is for.. so you can crimp on it and stop the bullets in following rounds from getting inertia pulled while sitting in the magazine. Every thing has a trade off. Seat out long to near the rifling and ususally accuracy gets real fine. But if the bullets move on recoil you have to stop that.
A Lee Factory Crimper gives the option of long seatint but still crimping (you can overdo that).
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Old October 30, 2011, 03:12 AM   #3
Scorch
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That groove is called a "cannelure", and it is indeed for crimping the case mouth into without damaging or deforming the bullet. You do not need to crimp, but you can id you wish to do so. If you are going to crimp, the case mouth should be about 1/2 of the way up the cannelure. But as Missionary stated, for best results you should find out where your bullets are in relation to the rifling and magazine length.
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Old October 30, 2011, 03:14 AM   #4
UtopiaTexasG19
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Cannelure
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Old October 30, 2011, 07:24 AM   #5
mehavey
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Quote:
I know the Maximum C.O.L. is 3.29 inches....
First question is whether you know that from reading it in your loading manual, or whether you have actually measured it in the rifle itself (?) If you've measured the actual distance-to-lands (unlikely), seat it just short (~20-30 thousandths) of that.

If you haven't measured it yourself, seat to the middle of the cannelure and crimp as normal. (The reason here is that the Hornadys have a longer bearing surface/more squared-off angle to the point than most bullets, and seating to the shorter OAL is normal.)

FWIW: When I load SSTs in my Model-70, seating to the cannelure (which sure looks short) actually clears the lands by only 0.005")

Last edited by mehavey; October 30, 2011 at 08:07 AM.
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Old October 30, 2011, 09:53 AM   #6
PA-Joe
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3.290" is the COL that Hornady lists in their #7 Manual for a 154 grain SST. You should still check to make certain this will cycle through your magazine. As others have noted you can seat to the cannelure (or interlock groove).
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Old October 30, 2011, 11:52 AM   #7
Jim243
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Did you trim your cases down too far???


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Old October 30, 2011, 02:12 PM   #8
dunerjeff
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The cannelure doesn't have to be in the case(except on magnums or some autos maybe),I shot interlocks and they were always longer than the canelure groove.Just find where the max oal is for your gun and make them .01-.03 shorter(whatever lenght shoots best)and ignore the canelure IMHO.
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Old October 30, 2011, 04:23 PM   #9
mehavey
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Quote:
Did your trim your cases down too far???
That was my thought as well.
BWood, what's your as-trimmed case length?

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