[MP Sniper]

Any body have any accurate/consistent loads using the .243 105gr hornady A-Max bullets?

if you could even just start me out with what powder would best work with the A-Max that would be a big help?

[Art Eatman]

3031 gives me tack-drivers with the 70grain Hornadys and the 85-grain Sierra HPBT, but I've not used the 105s.

I tried 100-grain Noslers, but my twist is apprently too slow to get decent groups. I vaguely recall I used H414. Been a long time gone, though.

[MP Sniper]

what kind of twist are you shooting with the 70 gr. Hornadys and 85 gr. Sierra HPBT

[halvey]

It's all on Hornady's website. Or you could just buy the book.

[hagar]

There is only 1 powder for the 243 Remington, 4350. Does not matter if it's H4350, IMR or Accurate. Start at 40 grains and work your way up.

[Smokey Joe]

here with IMR 4350 and 100 grain bullets. Have not used the A-max bullet however.

Almost agree with Hagar--IMR 4350 is the powder of choice for the .243Win. But different rifles do have different likes and dislikes.

[GooseGestapo]

I've had better results with the 100gr and 105's with Reloader #22.
My most accurate load was with the Nosler Maximum load of 42.5gr. They also claimed best accuracy with the RL-22.

The maximum WILL be lower for the 105gr bullet. I suggest starting 6.0gr low and working up looking for best accuracy.

My second favorite is H4831. But, with my last .243, about everything shot about the same except the RL-22.

Be aware that some manuals are now giving 40.0gr of IMR4350 as absolute max.
The Lee #2 gives the following:
XMR-4350 39.0gr max
H4350 40.0gr max
IMR4350 38.2gr max

My most recent experience indicated that these were indeed Maximum in my rifle.
Be cautious with the .243 as I've seen substantial variations in case weight and hence capacity. I also had an aquaintaince blow the bolt on a Remington M788 with a book listed load of powder and Speer 105gr bullet. The .243 is an excellent cartridge but much of the data for it is riding the ragged edge. Be Careful as it and the 7mm RemMag have reputations for pressure excursions.

[hagar]

I had a brain fawwt, 40 grains should be the starting point with an 85 Sierra bullet. Reduce at least 2 grains for 105.

Beware neck stretch on a 243. You size it, and when you pull the case out of the die, the neck sizing button stretches the neck out again, and your rounds will not chamber or be hard to chamber. The 243 is the only round that ever gave me this problem, and I tried different brands of dies with the same results.