.243 Win / 75 gr. NOE boolit load data?

Working on developing a cast boolit load for my .243 M700. Gun is about as accurate as one can expect from a factory barrel with a couple thousand rounds down the spout...i.e. 2 1/2"-3" @ 200 yds with 100 gr. JBs I recently acquired an NOE 244-75FN from a member here but none of reloading manuals have any data for a 75 gr. cast and a search here didn't find much except for a couple of 5-year old threads mostly concerning heavier boolits. My first attempts haven't been all that successful: 1 1/2" @ 50 and around 3" @ 100 from loads extrapolated from 85 gr. data in current (and old) Lyman Handbooks. Any shared experience or advice would be appreciated.

Bill

Nobody loading cast for the .243 or 6mm Rem? Hokay, will experiment a bit and post results when I have some.

Bill

I would start at 6 grains of Red Dot if I was reloading for 243. Should be soft shooting, but a gas check may be needed. My internet is slow right now at the lake. I will post some older Lyman reloading data later. W748 should be a good performer for faster loads.

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Originally Posted by Kraschenbirn

SNIP...

NOE 244-75FN from a member here but none of reloading manuals have any data for a 75 gr. cast and a search here didn't find much except for a couple of 5-year old threads mostly concerning heavier boolits. My first attempts haven't been all that successful: 1 1/2" @ 50 and around 3" @ 100 from loads interpolated from 85 gr. data in current (and old) Lyman Handbooks. Any shared experience or advice would be appreciated.

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Bill,
My attempts read much like yours. I used Lyman's 85gr data. I cast them using COWW- air dropped, Bhn=13, sized to .2455" ...copper GCs, and lubed with SL68B. The best I got was 3" groups at 100yd when I was working up a load. After which, I was able to tightened the groups of the best load, to about 2" when I Heat treated the COWW boolits to 22 BHN.

I used Alcan 9450 (a milsurp from Jeff Bartlett) using SR4759 data, which is what it's suppose to be like.
I worked up a load starting at 12.5gr, but groups were best at 15.5gr which clocked at 1976 fps.
COAL=2.465 (touching Lands on my Savage Axis).

For my purposes, 3" at 100 is fine. I shot 10 shot groups and rarely had any fliers.

Note that the Lyman Cast Bullet book says their accuracy fell off with velocities over 1750fps. They used a 1-10 twist barrel. Their data for the 6mm Rem says the same thing and the test barrel for it was 1-9 twist.

I run starting jacketed book loads of IMR4831 behind an,as cast 85g Saeco in a bone stock 1980 R700V. It shoots bugholes. Of the 1/2 dz 243's here,Savages.. R700's... and one TC prohunter,I just can't get the velocity out of the smaller case. And the 6 is a faster twist. The Saeco is a tapered bore ride,and while there's obviously no complaints in the big six...

I prefer taking straight nosed,bore riders and running them through a custom tapered nose die. It boils down to fit(doh)... the Saeco has a very short tapered section,vs the dies you can make. And you really need a cpl different tapered reamers here. Think of it this way,if you're geared/tooled up to make one,make several. Just use a different taper on your reamer. It can get very difficult to put into words on the metrology here. Yes the stated reamer specs are important but it's not until the bullet comes out of the die that you get the realtime data. Just sayin,what goes in ain't always what comes out. The very same can be said for the chamber's leade. Just because the reamer print says "X",what it is,and how it interfaces with the bullet nose is still,at that point unanswered. Basically you have written data,all good so far.... but until you put it into practice you're not getting the true picture. One more reason theory is exactly that,a theory.

Lots more to it. Just sayin,try a nose tapering die. More often than not,they work really well. Also,you really need to buckle down on your casting.... weigh your bullets. Not for segregation,weigh them to confirm your casting techniques. You should be holding extremely tight weights on them if you're holding your mouth right. If you have 1g differences showing up,that needs fixing before you move on.

Good luck with your project.

I was wrong on 6 grains. Book says thats too low.
http://marvinstuart.com/firearm/Manu...-%20Reduce.pdf

With a gas check, try 14.0-16.0 grains of 2400, 26-28 grains of 748, 22-24 grains of 3031 or 16-18 grains of 4759, if you have any. These are loads I shot using a 244-496 which was ~8 grains heavier than your boolit. I'd also consider 8-10 grains of Unique or Herco, but I never tried either. IIRC, 2400 worked the best from an accuracy stand point, followed closely by 4759. But truthfully, I never got really fine accuracy. 15.0 grains of IMR 4227 was suggested to me later, but by then my .243 and its mold had both left the building.
Good luck!

I got great groups with the 84 gr Ly and the 95 rcbs with 12 gr 2400.

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Originally Posted by rintinglen

...15.0 grains of IMR 4227 was suggested to me later, but by then my .243 and its mold had both left the building.
Good luck!

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Not cast but my 6mm Rem Ruger M77 Sporter 1 in 10" with 16.0 IMR 4227 80gr J bullets and no filler would put three in one hole at 50yds. Loaded for my kids when they were young.

Thanks to everyone for their inputs. Gianni's 12.0 gr. of 2400 under my PC'd NOE 75 grainers, off the bench @ 100 yds, print awfully close to MOA...like 1 1/4" for 8 rounds (last of what I had loaded)... and (lifted from my oldest Lyman Handbook) 8.5 gr. of 700X with the same boolit comes in a close second at just about 1 3/4". I'm going to tinker with both loads but, as is, either is quite adequate for practice and general plinkin'.

Bill