First Reloads for new 300 win mag - test targets

[joe_skeeter]

These loads are using new Winchester 300 win mag brass using Win Large rifle primers and H1000 powder with SEI 190 gr HPBT. Shooting at 100 yrds with targets with 1/2 lines. The grain are listed with the chronograph data. My next step is to focus on the 79 gr load and reload the same brass and only neck sizing. I will shorten and lenghten the oal to see what effect it has of the patteren. The gun is a AI AWSM 300 win mag and this is only my thrid time shooting this gun. Any suggestion welcome.

 

[desertHK]

Re: First Reloads for new 300 win mag - test targets

looks like somewhere between 78 and 79 grains, you may just find the pot of gold at the end of the rainbow. Good luck. If you can find it, try the 208 AMAX.

 

[noahmercy]

Re: First Reloads for new 300 win mag - test targets

If you can't get the groups you want with H1000, you may give RL22 a try.

Groups from my 300 Win Mag meat gun (Ruger MKII All Weather) shrank by nearly 25% with heavier bullets- 180 grains and up- when I went to RL22. I also saw some reduction in groups when I switched to Remington 9 1/2M primers. I know that all firearms are different, but my go-to load of 75 grains of RL22 under a 180 grain Hornady or Nosler has proven accurate from every 300 Win Mag I've tried it through.

 

[SooStan]

Re: First Reloads for new 300 win mag - test targets

H4350, IMR 4350 and RL-17 gives me the best groups. RL-17 gives about 100 fps more velocity over the other 2.

 

[TOP PREDATOR]

Re: First Reloads for new 300 win mag - test targets

i've used imr 4350 with great success in the 300 win mag., especially with 165 and 180 gr heads.