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Elvis Super Member


Joined: Jul 27, 2008 Posts: 9359 Location: south island New Zealand
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Posted: Tue Oct 10, 2017 1:27 am Post subject: very similar cartridges |
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ok you reloading gurus here is my delema and solution....  did I get my maths right??????
mates rifle uses a .204ruger case necked back up to .224 cal
so its parent the .222 magnum has shoulder about 2mm --1/16th" shorter and little bit less powder capacity
we did bit of a ladder test using win 748 powder and 52grn projectiles and topped out with pressure at 30grns
29grns was fine so we loaded and fired a few of those all ok
so looking in older manual that has .222magnum data
it appears to be this cartridge/rifle runs about 1.5 grns more than the 222 magnum
looking at data for the .222magnum it drops a full grain of powder per 5grns projectile weight
SO if I use .222 magnum data and add 1 grn to that I should be about right???????
have loaded up 20x 50 grn loads with 29grns powder so have kept load same but dropped 2 grns projectile weight
also 4x 70 grn loads at 27 grns....the data for 222mag had 26.5grns
 am I doing maths right???????
plurry lot of pissing around compared to good old .223
look forward to your replies
_________________ You shot it You pluck it !
Them who eats the most duck eats the most feathers! |
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slimjim Super Member


Joined: May 16, 2009 Posts: 8317 Location: Fort Worth TX
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Posted: Tue Oct 10, 2017 5:59 am Post subject: Re: very similar cartridges |
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Ok, Elvis. 5 grins of bullet is 1.0 less grain of powder. Going from 50gr to 70gr pill would be a reduction of 4.0 grains. 29-4=25 30-4=26 26.5 is higher than either. You might load one or two 70 grain bullet with less powder and test fire them first, e.g., 25.5 and 26.0. If 26.0 is ok pressure wise then proceed. Also, mark the impacts as these first three shots might give a clue to the accuracy node depending how they group.
_________________ "To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt
"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein |
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Elvis Super Member


Joined: Jul 27, 2008 Posts: 9359 Location: south island New Zealand
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Posted: Tue Oct 10, 2017 11:38 pm Post subject: Re: very similar cartridges |
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ok from manual .222magnum data
40grn =26.5-29grns of 748
50grn=23-28grns of 748
60grn=22-27grns of748
70grn=23.5-25.5grns of 748
so it looked to me like  I COCKED UP ABOVE POST
good spoting Slimjim
its 1 grn less powder per 10 grns projectile weight
we tested a 52grn and settled at 29grns
so my 50grn projectile loads with 29grns powder will be fine.
agreed the 70 grn loads are 1.5grns above magnum data....which is not the 1 grn predicted.
will try em and see,they are barnes tsx with huge grooves around then to ease pressure..... dont have many of them but just had to try them out in the 1 in 8" twist barrel......
funny part is my mate thought he was stoking far more powder in than what we are now......
_________________ You shot it You pluck it !
Them who eats the most duck eats the most feathers! |
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slimjim Super Member


Joined: May 16, 2009 Posts: 8317 Location: Fort Worth TX
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Posted: Wed Oct 11, 2017 5:19 am Post subject: Re: very similar cartridges |
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Elvis, since its not your rifle, you might still load two more at the 0.5 grain less powder increments just to be safe. If the Barnes bullets are more than 0.050" from the lands, you are likely ok but .....
_________________ "To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt
"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein |
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Elvis Super Member


Joined: Jul 27, 2008 Posts: 9359 Location: south island New Zealand
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Posted: Wed Oct 11, 2017 11:42 am Post subject: Re: very similar cartridges |
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cheers Slim.
_________________ You shot it You pluck it !
Them who eats the most duck eats the most feathers! |
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Elvis Super Member


Joined: Jul 27, 2008 Posts: 9359 Location: south island New Zealand
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Posted: Sun Oct 15, 2017 12:41 am Post subject: Re: very similar cartridges |
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well that was exercise in frustration.... first shot 4" high then two 1" apart..all 2" to left.
fired single 70grn load and it pierced the primer.....thats a first for me ever.absolutely no flattening of primer just neatly pierced. will pull loads and put the powder to better use in .223.
oh and the 70 grn was 3" to left
lad lost all confidence in rifle after first shot went that high,along with the 3 misfires we had the other day.looked a bit harder at rifle and cant see bedding anywhere,that along with the chopped magazine box to fit extra length make it a hackjob....Nathan far happier to use the .308 BLR......fair enough.
_________________ You shot it You pluck it !
Them who eats the most duck eats the most feathers! |
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slimjim Super Member


Joined: May 16, 2009 Posts: 8317 Location: Fort Worth TX
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Posted: Sun Oct 15, 2017 4:54 am Post subject: Re: very similar cartridges |
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Elvis, thanks for reporting back with the results. Was the first shot that went high from a clean bore? I typically see that happen and make sure I put 1 or 2 rounds down the tube before I do any shots for accuracy.
_________________ "To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt
"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein |
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Elvis Super Member


Joined: Jul 27, 2008 Posts: 9359 Location: south island New Zealand
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Posted: Mon Oct 16, 2017 1:04 am Post subject: Re: very similar cartridges |
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well sort of.....lightly oiled rag on jag been pushed through it before storage but not copper solved etc.
all my other rifles get same treatment and all shoot cold bore to same place as the rest.
_________________ You shot it You pluck it !
Them who eats the most duck eats the most feathers! |
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slimjim Super Member


Joined: May 16, 2009 Posts: 8317 Location: Fort Worth TX
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Posted: Mon Oct 16, 2017 5:44 am Post subject: Re: very similar cartridges |
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Elvis, this rifle may be different. Once hunting season starts, I don't clean my rifles or touch the bore until the season is over. If I have to clean/touch the bore, I always do at least 1 fouling shot. I've seen 3" of POI difference between cleaned and fouled. Once a sniper goes into the field, they don't touch their bore either.
_________________ "To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt
"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein |
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Vince Site Admin


Joined: May 25, 2005 Posts: 15957 Location: Brisbane AUSTRALIA
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Elvis Super Member


Joined: Jul 27, 2008 Posts: 9359 Location: south island New Zealand
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Posted: Tue Oct 17, 2017 1:37 am Post subject: Re: very similar cartridges |
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ah the good old CLP...love the stuff...always thought they should make TV add with Queen as sound track.....I've got my "break free"......
_________________ You shot it You pluck it !
Them who eats the most duck eats the most feathers! |
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