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English Mike Super Member
Joined: Jan 08, 2007 Posts: 1709 Location: Whitehaven, Cumbria, UK
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Posted: Sat Aug 02, 2008 12:53 pm Post subject: Re: CUP formula |
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Interestingly, Lyman lists their STARTING load for the 85gr HPBT using H4831 as having the greatest potential for accuracy & that's 5.5gr below the max. load.
Start load:
41gr
2832fps
36,400CUP
Max. load:
46.5gr
3266fps
49,600CUP
Oddly enough, when using the same powder but a 90gr FMJBT it's the max. load that is rated as having the best accuracy potential.
Fascinating stuff.
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phill21 Member
Joined: Aug 02, 2007 Posts: 145 Location: Western Australia
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Posted: Sat Aug 02, 2008 1:37 pm Post subject: Re: CUP formula |
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Welcome Dmickey, good to see you stepped right to the plate mate
nothing wrong with loading for accuracy, i am just traveling down the same dirt track as most reloaders when they have not been reloading long.
Although i do get to pick the brains of some mighty smart people along the way
You know looking at the time some of these posts where done i see a few non sleepers HMMM Bushy>
phil
_________________ no matter what happens my mother still loves me. |
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Bushmaster Super Member
Joined: Jun 12, 2005 Posts: 11390 Location: Ava, Missouri
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Posted: Sat Aug 02, 2008 2:28 pm Post subject: Re: CUP formula |
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I hate to be the one to tell you Phil, but it is only 1630 here and I don't go to bed until 2400...I'm up at 0700 to feed horses...
_________________ I have one nerve left and yer standin' on it...
DEMOCRACY Two wolves and one sheep voting on what to have for lunch...
LIBERTY A well armed sheep contesting the outcome of the vote... |
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chambered221 Super Member
Joined: Aug 17, 2007 Posts: 3455 Location: Lost for good !!!
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Bushmaster Super Member
Joined: Jun 12, 2005 Posts: 11390 Location: Ava, Missouri
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Vince Site Admin
Joined: May 25, 2005 Posts: 15704 Location: Brisbane AUSTRALIA
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shrpshtrjoe Super Red Neck Member
Joined: Jan 26, 2005 Posts: 2965 Location: Maryland
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Posted: Sun Aug 03, 2008 4:39 am Post subject: Re: CUP formula |
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dmickey wrote: |
What's wrong with loading for accuracy instead of velocity? I'm sure the game won't notice a slight decrease in velocity! |
Welcome to the HuntingNut dmicky. I agree . Accuracy (imo) is more important than speed. Less pressure is easier on your equipment your barrel will last longer you get more reloads from your brass ect.. I have only had one rifle that shot better at max loads a Win mod 70, 264 Win Mag. If I need to push a cartridge to the limits to get the performance I need then I will use another cartridge for the particular task.
Joe
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Bushmaster Super Member
Joined: Jun 12, 2005 Posts: 11390 Location: Ava, Missouri
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phill21 Member
Joined: Aug 02, 2007 Posts: 145 Location: Western Australia
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Posted: Sun Aug 03, 2008 5:39 pm Post subject: Re: CUP formula |
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Bushmaster wrote: |
I hate to be the one to tell you Phil, but it is only 1630 here and I don't go to bed until 2400...I'm up at 0700 to feed horses... |
AAAH!! I knew that
Using winchester brass, winchester 9 1/2 primers WIN 760 powder 85gr Seirra HPBT with an OAL of 2.585"
Its not raining so grabed my guns and bye dear, ran couple of foulers thru sigted my rifle for 200mts and tryed the load not bad 1.3" @ 200 so sighted her in for this round grabbed the young (37) and went out to the mates farm spotlighting.
Lost count of the roo's we shot but got some realy nice skins and the 85 HPBT out to 400 sure makes mess of the roo's.
Took a rabbit @ 100mts the 85 HPBT turned him inside out and 1/2 skinned him wish it was a tracer it could have cooked for me too>
Cheers phil
_________________ no matter what happens my mother still loves me. |
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ElyBoy Super Member
Joined: Apr 04, 2006 Posts: 1541 Location: Forest Lake Minnesota
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Posted: Sun Aug 03, 2008 7:17 pm Post subject: Re: CUP formula |
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Sounds like you are having WAY too much fun Phill.
I have to wait a month yet to kill anything.
Glad to see that you are getting good accuracy.
1.3" Groups at 200 yards isn't nothing to sneeze at. That is one fine group with any load.
Eric
_________________ NRA Certified Chief Range Safety Officer
NRA Certified Pistol Instructor
DNR Certified Firearms Safety Instructor
NRA Life Member |
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btefft Rookie Member
Joined: Aug 31, 2008 Posts: 21 Location: Columbus, Ga
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Posted: Sun Aug 31, 2008 2:25 pm Post subject: Re: CUP formula |
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There is no reliable formula for CUP and FPS. Don't waste your time.
Besides, I stay in the mid ranges of reloading and only look to compare pressures of one recipe versus another.
For example, I see in the Lyman 49 Manual (p310) that
IMR-3031 - 47.2 grs - 1621 fps - 19.800 CUP
AA-2015 -- 44.5 grs - 1585 fps - 21,100 CUP
What strikes me is that AA uses less powder, develops slower fps, yet produces a HIGHER CUP.
For that reason, I would use IMR-3031.
Hack
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hunterjoe21 Super Member
Joined: Mar 30, 2007 Posts: 1486 Location: Miles City, Montana
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Posted: Thu Sep 04, 2008 8:07 pm Post subject: Re: CUP formula |
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I too was obsessed with velocity when I first started loading ammo. Didn't take long to realize that "Faster aint always better" as Grandpops used to say....
As a friend at the gun club says...
"You can't KILL it if you can't HIT it"........
_________________ My 1911 is more effective than your 911. |
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