Do the 95 grain Nosler BT and the 95 grain Winchester Combined Technologies use the same load data, or does the black coating on the WW CTs make them slicker and therefore use more powder. The reason I ask is that a close friend of mine had a bunch of loads made up by a mutual friend who has since passed away. He now needs more loads. When I broke down the CT load, there was a charge of 46 grains of H4831sc in the case. That is at least three grains over the Nosler manual max for the BT.

Sorry for your loss.

I imagine your deceased friend was using data from a much older manual. My 1970 Lyman 45th lists 45 gr of 4831 as max for a 100 gr jacketed; that would be the original 4831, not today's H4831. The safe thing to do would be to start over.

Nosler's manual says to use the same data for both bullets.

Someone more knowledgeable can give more details on the coating, supposedly it is an oxide of some sort.

http://www.winchester.com/learning-center/faqs/Ammunition/Pages/ammunition-question095.aspx

http://www.winchester.com/learning-center/faqs/Ammunition/Pages/ammunition-question090.aspx

Is there any chronograph info for these loads by chance?

What case manufacturer is being reloaded? Cartridge overall length?

I think you should work up a new load instead of making decisions based on taking one apart.

Yep, nailed it.

Leon, for most practical purposes, the CT is interchangable with the NBT. In one or two instances I've had to back off a bit going from the CT to the NBT, but not 3 grains worth.

IMO some of Nosler loads involving H4831 are on the anemic side.

Regardless, there is not substitute for working up and testing yourself.

+1 on working up a new load. Even when I start with a new can of powder, I back off and start fresh on a load. Powders vary from lot to lot and Son of Gael stated, the loads for the original 4831 aren't the same as for 'modern' version of 4831.

Thanks guys. Yes, I intend to develop a new load, but I could not imagine a good reason for the load to be a full four grains over Nosler's max. I know that some of the Nosler data is a bit light, but not by that much.

"When I broke down the CT load, there was a charge of 46 grains of H4831sc in the case. That is at least three grains over the Nosler manual max for the BT."

Am I missing something here? If that powder is in fact H4831SC there is no way it could be old milsurp H4831. Are the ammo boxes labeled as H4831SC? AFAIK load data for the two bullets is the same.
Paul B.

It seems that the burn rate of H4831 has gotten faster when production moved to ADI in Australia.......

The ammo box was labeled H4831sc, but there was no charge amount listed. So I pulled the bullet on the one remaing case after measuring the COL and was amazed to see the weight on the scale, and yes the scale is accurate. Tim told me the load was hot, but holy cow.

Sounds like his method of working up loads was to get to the point the primers fall out, then back off 1/2 gr.

Powder formulation is subject to change. I believe mule deer has commented on this. Giving the period of time that has lapsed you most likely will be dealing with a different formulation.

Shod