I just was given a 6.5 x 300 weatherby and would like to get started loading with it. I was told by the techs at sierra to try the 6.5 STW data to get started. Has anyone got any advice where to get more loading data on this cartrige? Also I was given 4 cans of H570 they look a little old and I have never heard of it.

Looks to me like the 6.5-300 would hold about 4-5 grs more powder than the STW. So I would say it is a good place to start.

As to the powder. My old manual list it as close to H870 loads are 1 gr highr for 570 than 870. It has been out of production since 1979 I believe.

Thanks for the info ramrod340 I'll start with the 6.5 data and go from there.

Alfonz

I believe I can help. H570 was a surplus slow powder from military ammo probably 20mm cannon. There are a lot better choices today. I would start with Vihta Vuori N170, R-25 and Retumbo in that order. The ultimate powder might be VV 24N41 but expect to pay over $100 to buy some.

How long is your barrel? The longer the better for this caliber and these slow powders. Having shot a lot of bullets in 6.5, I believe the Barnes TSX and Sierra 140 Gameking would be the most accurate. Nosler 120 ballistic tips are great in 9 twist barrels for way out coyotes. The varmint bullets 85-105 grains arn't usually accurate in fast twist barrels.

Thanks again for the help with this I'm a little green when it comes to the wildcat stuff.
Now what about some suggestions for sizing brass?
I tried one 300 weatherby through the sizing die with ample lube and managed only to size half the neck before I bukled the shoulder.

Humbly
Alfonz

Buckling necks. You're coming down 3 calibers, it may need an intermediate sizing. Suggest you try the boys on the Wildcat forum on this one.