I was wondering what powder everyone likes for the 75HP bullets in the 243 Win and 6mm Rem.

WW748 & 760 work for me.

I shot alot of I4350 when I owned those calibers.. It may not have been the best, but it was accurate..

It starts and ends with IMR 4064

Varget

What he said.

I like IMR4895 and Varget.
Varget is all I've bought lately...

H4350, Varget & RL-15 which meters better than the 1st two.

MM

I use Varget and H4895. Varget is hard to find right now so this PD season was with H4895.

I have a 6mm Rem on a Rem LA, with a PacNor barrel with a one in 7 twist rate..

with the 75 grain HP, from Hornady... I tested 15 powders for accuracy...

only one was not accurate for the application... ( forget which, as it was a while ago)... but the hands down leader was H 414....this is the most accurate rifle I own, and this was the most accurate powder of all tested...

IMR 4064 is NEVER a wrong choice tho in my experience......in about any caliber I routinely shoot.

Win 760 is the most accurate powder in my 6 mm Rem, but H414 and Win 760 are one and the same just labeled different on the can.

I have found 4350 very accurate in the 75 Hornady and Sierras. Both were/are extremely accurate Most recently, I loaded some 70 Sierra BTHP with 8208, 36 grains. First time out, they shot into .180 for three shots. Went out a few days later to prove it was not luck and shot another group just over .200. And on top of that, the BC on the 70 gr. Sierra is better than the 75 gr. Sierra.

The places I varmint hunt seldom has wind over 5-6 mph so I am comfortable with the choices.

For the .243, RL-15 or Varget for 75's (never loaded for a 6mm). I never found H-4350 to be as accurate with the 75's, but for 85's-105 H-4350 is my preferred powder.

Years ago when i had a 243 i was useing IMR3031. Probably better powders but it shot great groups. This was with 75 gr. Hornady and Sierra bullets. Did try H4350 but went back to 3031.

H-4895 up to 80 grs. H- 4831 85 and up.

I like 3031 for the middleweights too.

I use Reloder 19 with 75 grain v-max in my 6mm Rem.Very accurate and fast.

brassloader,

RL19 has been my go to powder in my 6mm rifles for 12yrs now and I fully agree with you about it. The only difference is I use the Sierra 75HP's.

I have actually used in my 243's also but I think there are better choices for the 243.

I've had three 6mm Remington's over the years and all liked RL-19 too, but never had the same luck with 19 in .243's as the 6mm, where the 4350's normally shoot more accurately. Dunno why, but there it is.

Mule Deer,

I have had good luck with IMR4831 in the 243's but I never for whatever reason liked 4350. A good friend of mine has very good results with IMR4350 and also IMR4064 in his 243's. I have also had good luck with IMR4064 in my 6mm's.

I am thinking seriously about trying Win 760 in both my 243's and 6mm's. Have you had any luck with that powder in those two calibers.

The most accurate powder in my 6 mm is Win 760, 243 IMR 4064

Never have tried it much in the .243, because it's pretty temperature sensitive, which doesn't work well with Montana weather.

Before discovering that I did use 760 in several cartridges to develop very accurate and, often, fast loads. But accuracy, velocity and presssures tended to vary when the rifles were shot at very different temperatures than when the load was worked up.

I do include 760/H414 in handloading tests for publication in various magazines, because it works fine for hunting where temperatures don't vary all that much. But according to my loading notes that hasn't been in any .243's. I tend to select powders for such tests by going through published data to find powders listed as giving top velocities or (these days) finer accuracy, or both, and 760/414 didn't make the list for any .243 testing.

For example, Nosler lists H414 as providing the top velocity with 70-grain bullets in the .243, 3630 fps. But right behind H414 at 3616 fps is Varget, which Nosler also shows as the most accurate powder with 70's in their tests. And Varget has always proven very temperature-resistant in my tests with various rifles. And with heavier bullets in the .243, slower powders than 760/414 provide more velocity.

This doesn't mean 760/414 won't provide good results, it's just that I've never found it optimum for any purpose in the .243.

My 6mm Rem was an AI. Best accuracy across the board came from Win 760. However, I also had some really weird things happen pressure-wise. After working up a load, I'd load 50 rounds. At the range, everything was fine. With the same box of ammo, though, up in the woods shooting squirrels, I'd fire a couple or three shots, then run into wild pressure excursions. It wasn't a temperature issue. Never did figure it out.

Tom