Greetings:

I just received word my LSR .243 has been completed. It has an 8-twist 22" Broughton barrel.

I will be using 107gr Sierra MK's, Lapua brass and Fed 210M primers. I have a pound of H4350 and H4831SC.

Given the reloading manuals are religiously cautious with their "max" loads, can someone give me some real world maxes with these two powders. So far I've been advised (by reputable chaps) of 44.0 to 44.5 or so with both.

Thanks.
Matt

Hope your twist is fast enough a 1 in 7 may have been a little better choice. But you'll know soon.

Actually, the Sierra rep and the 'smith who put the project together both said an 8" twist was perfect. I'd need a 7.5 or so for the 115's, but that's a bit more bullet than I want/need.

Thanks for the input.

Although they can be pushed faster in a 243 and especially in a 6mm Rem, the 107 Grain Sierra has its best accuracy at about 2800 to 2850 fps.....

so load your 243 accordingly....

the one in 8 twist is also just fine at that MV...

cheers
seafire

I don't believe you'll want to load 44 grains of any 4350 with a 107 grain bullet. With the old H4831 I have used 45 grains with an 100 grain bullet, and was a bit too hot with the 105 Speers. In my rifle with a 22 in. barrel, 42 grains of 4350 and the 100 Sierra goes 2950, so is probably near max. and I would be careful loading that much with a 107 grain. The 8 in. twist should be great. That is what the factories should use, as I have never had a problem getting light bullets to shoot well with a quicker twist and the heavies shoot a lot better.

H-4350 From 33.5 grains to 39.6 grains
Remington 9-1/2 Primer

H-4831 From 36.5 grains to 42.5 grains
Remington 9-1/2 Primer

I liked:
IMR-4350 From 34.8 grains to 40.8 grains
Remington 9-1/2 Primer

"Each rifle is an individual" <--Bob Hagel.

Work up a load using a chrongraph and every bit of information in more than one handloading manual.

The 6mmBr site may have some feedback for you.

http://www.6mmbr.com/index.html