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May 17, 2009, 04:12 PM | #1 |
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C.O.L. for .270 Win. Nosler Partition 150gr
Hi...
I have been unable to find a recommended C.O.L. for the Nosler Partition 150 gr. for the .270 Win. I shoot a Win Model 70 sporter. Hoping to find some factory specs, but they have been elusive for this bullet. I found some load data on the Nosler site, but didn't include the C.O.L. Thanx!! |
May 17, 2009, 05:59 PM | #2 |
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COAL is rifle specific, not manual specific. From Accurate powders web site.
SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must be seen as a guideline only. The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination. This parameter is determined by various dimensions such as 1) magazine length (space), 2) freebore-lead dimensions of the barrel, 3) ogive or profile of the projectile and 4) position of cannelure or crimp groove. |
May 17, 2009, 06:50 PM | #3 |
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270 Win
150 Nosler Partition COL 3.320" You need a good loading manual, as a COL is always listed for a particular bullet weight for a starting point.
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May 17, 2009, 07:28 PM | #4 |
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Shoney...
Thanx... I use the Speer manual and I love it. It's dog eared. I use the C.O.L. from their tables most of the time... in fact I usually just buy Speer bullets when I am loading for the .270. Perhaps there is something I'm not fully understanding... I've tried to figure out what the C.O.L. needs to be for a particular bullet in my rifle by trying to find the length that will put the bullet just behind the lands... I quit trying to do that for two reasons, I don't have confidence in my "home brew" method and from what I understand it may not make enough of a difference in accuracy to justify the hassle, risk, etc... So, I use the C.O.L. that I can find from the manufacturer of the bullet I use... The shape (ogive) of these Noslers are different from the GS-SP from Speer. Should I just use Speer's C.O.L. and assume that the point where the bullet sits in relation to the lands is close enough??? Also, most of what I load, Hornady SST and the Speer GS have cannelures and I figure I can't go wrong seating the bullets there. The Nosler partitions do not have the cannelure. I realize I am probably over complicating things... If the C.O.L. is just dependent on weight, then I'm gonna quit worrying about it!! Thanx.... sorry for going on so long. Mark |
May 17, 2009, 08:58 PM | #5 |
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Shooterdoc--My factory Federal 150 gr. partitions measure 3.190. Out of the 6 that I measured they ranged from 3.183 to 3.193. This might be a place to start.
I have been frustrated with the same thing from Nosler. They quote the industry standard length, then say something about a longer COAL resultes in better accuracy. Not much help, unless you are inclined to figure the length from the bolt to the lands etc. Roger |
May 17, 2009, 09:08 PM | #6 |
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Most of the rifles produced today have "short" magazines. If you load your cartridges at the longest COL that will fit and function properly from the magazine, they will be well short of 0.070" off the lands. Usually, if you load cartridges at 0.070 to 0.010 off the lands they will not fit in the magazine, and they will have to be fed directly into the chamber one by one.
Likewise, ammunition produced by factories are usually much shorter than the shortest magazines. Many postulate that this is done so the ammunition will fit any magazine. Others also postulate that magazines are short because the lawyer section of the companies do not want law suits from weapons that will allow bullets being jammed into the lands.
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May 17, 2009, 09:25 PM | #7 |
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Thanx Colorado and Shoney...
Great info... good to know those Federal COALs... increases my confidence. Shoney, I like what you said about how a round won't fit in the magazine if the bullet is seated for a COAL that's too long.... So, Thanx... very helpful! Also glad to know I'm not the only one a little frustrated, I thought it was something I wasn't getting! |
May 17, 2009, 09:43 PM | #8 |
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Shape of the ogive has as much to do with possible COL as the weight, where really the issue is length. Heavier bullets for a given caliber are longer.
The "shade tree" method to get you in the ball park is easy and cheap. Remove the bolt, drop one of the bullets into the chamber. Give it a light tap with a dowel to verify it's up against the lands. Take the dowel and gently slide it down the barrel until you feel it contact the bullet. Mark it at the end of the barrel. Knock the bullet out. Replace the bolt. Slide the dowel back down the barrel and mark it again. Measure between the two marks. If you've been careful, you have a close approximation of a COL where the bullet would be against the lands. It will certainly be close enough to tell about how far from the lands it would be if shortened enough to fit the magazine. |
May 17, 2009, 09:56 PM | #9 |
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Well, that I CAN do. Thanx oldscot!
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May 18, 2009, 10:36 AM | #10 |
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I have the same rifle.....
.....Classic Sporter model 70, also in .270 Winchester. And it's favorite bullet is the Nosler 150 Partition. In my rifle this bullet can be loaded as long as possible for the magazine and it's still not touching the rifling. My magazine length is 3.400 inches but I have to load .010" less or the ammo will hang up. So 3.390" works well for me if I'm using Nosler Partitions or Sierra Gamekings or the same style of Speer bullets, all 150 grains of course. When using Hornady bullets I have to load to a shorter length because their shape causes them to touch the rifling before I've used up available space in the magazine. So I load 'em pretty long and my rifle shoots the Nosler Partition best with a stiff charge of Norma N-205 for a muzzle velocity that's right about 3,000 fps depending on anbient temperature. Hope this helps. Remember that your rifle will be unique even if it looks just like mine so things could be different for you.
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May 18, 2009, 03:31 PM | #11 |
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Shoney is correct with the manual. I am looking at the Nosler one and it is giving one for all of there bullet weights as 3.340". I guess they know there all differnt so there just giving the Maximum S.A.A.M.I. overall cartridege length. Like Shoney was saying you might get the perfect fit, but then it may not work thru the magazine. I load for my cousins .270 win. He is using the 150 grain ballistic tip in a Remingtion 700. I have those at a C.O.L. of 3.466" they are so long they look funny. But they cut his groups in half. I had to load up some dummy rounds just to make sure they would function thru the mag etc. They worked o.k. but alittle tricky loading them. Of course this was for his rifle only, and that type of bullet style. There is no doubt yours will be differnt. Colorado Redneck feels the same as me with the Nosler manual they dont give you much help on this, but you should get there manual just the same. You can try to figure out the C.O.L. for the best fit to the lands provided it works thru the magazine or you can go by what the manual suggest using. Dont take what anyone says as gospel typos are easy to make, you do need the manual, and figure it out for that rifle only. They are all differnt even if it is the same make. I just checked my Horndady, and Speer manuals they are all giving the C.O.L. at 3.340" my old Hodgon does not even give one.
Last edited by James R. Burke; May 18, 2009 at 04:06 PM. Reason: Add Info: |
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