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7MM Nosler ABLR

 
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  #8  
Old 03-24-2014, 01:33 PM
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Re: 7MM Nosler ABLR

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Originally Posted by Canadian Bushman View Post
I personally dont think a 7mm 150gn is a long for caliber bullet.
I also dont think a bullet not shooting well at 100 yds is something to be accepted. I have spotted for too many guys shooting 168's and 180's into ragged little holes at 100yds to say that these bullets need time to go to sleep.

I have nothing against testing loads at 2-3 hundred yards, that is a good practice. But i would pay close attention to my reloading practices, chronograph, and bullet run out while working up loads before accepting a bullet not shooting well at 100 yds. Typically after a bullet deviates from its flight plan, it does not return.
Amen, thats whats I always thought. How can a bullet not shooting well at 100 but shoot great at 3 or 400yd ??

I believe folks are forgetting the wind
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  #9  
Old 03-24-2014, 02:18 PM
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Re: 7MM Nosler ABLR

There are bullets that have high runout when seated and will throw groups up close, I.E., shoot a 1" group at 100 yds and also shoot 1" group at 300 yards. Sometimes this is because the bullet is leaving the barrel off axis and taking longer to align its nose to the direction its traveling. This does not have to happen and can usually be avoided when the ammo is loaded to its potential. Other problems can cause this as well but it seems long for caliber bullets exaggerate runout problems when fired through tight twist barrels at high speeds. It often gets accepted instead of cured.

1" groups at 300yds sounds like a accurate rifle but youre still giving up accuracy. If you fix the problem to the point where it will shoot .5" at a hundred chances are it will now shoot under an 1" at 300.

Im not gonna hijack this thread with a cartridge run out or physics discussion, but im betting if you work with those 150's enough they will will have no problem cutting ragged little holes at 100 yds.
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  #10  
Old 03-24-2014, 02:50 PM
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Re: 7MM Nosler ABLR

I loaded the 175 gr bullets and they seemed to shoot better at 0.020" jump. However, in powder work up, I only got one decent group (1.3") which was at about 2750 fps. Haven't' tested past 100 yards but with all the posts here, I might try them again at 200+.
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  #11  
Old 04-05-2014, 04:32 PM
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Re: 7MM Nosler ABLR

Well guys I was able to get these 150 GR LRAB to shoot in my New Kimber Montana 280 AI ,and I was able to get an honest .75MOA at 100yards during the barrel break in process . I will try again on not such a windy day, and hopefully I can get groups to shirk a bit more with some fine tuning ,and if not I think .75 with a 6.5LB gun is not so bad , I will also post more results as I get them but the main thing is they are showing some promise , I have a Cooper 280 AI that I will try them as well ,and post some results just need the wind to slow its roll for a day so I can get some good bench time in.
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  #12  
Old 04-05-2014, 05:30 PM
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Re: 7MM Nosler ABLR

I did some testing with the new LRAB 168gr. in my 1/8 twist barrel s/s Shilen in .284 Win .G.A.P. I am able to seat the long nose bullet way out. Only tried about 60 bullets but could not get the same accuracy as with the 168 Berger Vld. 3 shots at 100yds.into .05" all day long. Same loads.
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  #13  
Old 04-07-2014, 04:00 PM
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Re: 7MM Nosler ABLR

Bullets cannot "return" to a group once they have deviated from it. The phenomenon that people are claiming causes this is called epicyclic swerve, the common name for it is "going to sleep." It is a red herring, and even if it is present is to small an effect to be measured- lost in the noise as they say. Might as well say it was coriolis lol.

I don't doubt that people have shot groups at 300 yards smaller than 100 yards, but if this happens it is because of the shooter not a result of gyroscopic stability effects. It isn't uncommon for people to shoot better when they can't see the group as it develops.

The bottom line is, the laws of physics demand that dispersion in a group is proportional to the time of flight, and thus if you shoot a great group at 300 it would have printed even better at 200 or 100. Sometime I need to set up some clear cellophane to capture the group at 100 and 200 in front of a 300 yard target and prove this empirically.
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  #14  
Old 04-07-2014, 05:20 PM
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Re: 7MM Nosler ABLR

Quote:
Originally Posted by KYpatriot View Post
Bullets cannot "return" to a group once they have deviated from it. The phenomenon that people are claiming causes this is called epicyclic swerve, the common name for it is "going to sleep." It is a red herring, and even if it is present is to small an effect to be measured- lost in the noise as they say. Might as well say it was coriolis lol.

I don't doubt that people have shot groups at 300 yards smaller than 100 yards, but if this happens it is because of the shooter not a result of gyroscopic stability effects. It isn't uncommon for people to shoot better when they can't see the group as it develops.

The bottom line is, the laws of physics demand that dispersion in a group is proportional to the time of flight, and thus if you shoot a great group at 300 it would have printed even better at 200 or 100. Sometime I need to set up some clear cellophane to capture the group at 100 and 200 in front of a 300 yard target and prove this empirically.

Well there are a lot of people very experienced in the industry that disagree.

I don't know if the law dispersion would apply to a projectile such as a bullet that spins and cuts through the air, maybe a round projectile would be appropriate. I'm not saying you are wrong or right, I'm just saying there are bullet manufactures and people who do this for a living that have found some cartridge combinations have groups that will shrink slightly at medium range to long range.

Some theories surround the coriolis effect, some parallax another speaks to stabilization in general, comparing the swerving bullet to that of a car going to a straight road, hitting some ice and begin to get loose in the rear, letting the rear end slide back and forth, the car does this until it stabilizes, all the while continuing on the same path. Makes a little sense, but is it real? IDK...

There is enough talk and experience with this phenomenon for it to be real or at least something to consider, whether we understand it or not.
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