I have been playing around with a load for the 500 A2 with a 300 gr Barnes Original. I was using H-335 (wc-844), and had some delayed ignitions, and other unacceptable results. I think the answer might be IMR 3031, or even 4198. I got up to 3000 with 126.5 grains of H-335, (wc-844 surplus), but I know it can do better with a better suited powder. I went as hot as 129 grains of wc-844, but the speed slowed to 2850. I tried 138 grains, but I don't remember what it did.



Has anyone given this a try, any load data. You might wonder why I am doing it. This is the big varmint load.



The 450 barnes was doing 2750 with 120 grains of surplus 4895, 24" barrel. I am using 123 grains now, (safe max), but have not chronographed it yet.

For my CZ 550 based 416 Wby I have loaded quite a lot with 300 grs bullets. I only use Norma 204 powder (about the same as reloader 19). With 121 grs I have chronographed this load average at 3213 f/s , bullet used was a lathe-turned copy of the GS custom HV bullet (but without the boattail). No pressuresigns (though I must be close to max..) and long brasslife (15-20 times reloaded with these loads without any problems).

John,
I've got a jug of wc852 (h414) if you want to use it.

What i found what that i HAD to use federal 215 primers... even with RL15, or i got delays.

jeffe

In the 500 A Square, IMR 4198 will probably be your best bet, of the powders you listed. IMR3031 should work, but will probably be a tad slow. The Barnes Originals kinda scare me with regard to pushing them fast i.e. high pressure. This fear stems from the fact that these bullets have open bases, and I am always worried about core seperations in the bore i.e. leaving jacket in the bore. I load the 450gr Original, but keep the pressures down, well below 40,000 psi.

Scott