Best Powder for Belted Magnums

[Boyd Brooks]

I have been using Reloader-15 for my 358 Norma and 416 Taylor belted magnums. Just wondering if there might be a better choice?

 

[ChrisG]

Those two cartridges are on different levels of "overbore-ishness" For the .358 Norma mag, a slower powder than RL15 would probably be optimum, maybe RL19-RL22? for the .416 Taylor, RL 15 is probably a good powder as are 2000-MR or IMR 4320 level of burn rate. I don't know of many published sources of either of those cartridges, but I would look into getting the Lyman loading manual or maybe one of Lee's comprehesive collections of load data booklets. You would need one book for each caliber. Hope this helps.

 

[Shootist43]

Boyd, what kind of groups and velocities are you getting with your current loads? How do they compare to what you are expecting?

 

[Boyd Brooks]

Boyd, what kind of groups and velocities are you getting with your current loads? How do they compare to what you are expecting?

I have just picked up a chronograph and have not had a chance to use it yet! In my 416 Taylor I am shooting 70grs of RL-15 pushing a 400 grain Hornady bullet, with 50 meter groups of less than 1 inch, very happy with that. My 358 groups are out to 2.5 to 3 inches at 50 meters, with 67 grains pushing a 250 grain Hornady bullet, not happy with that! I was hoping to only need one powder for both! Might be wishful thinking, I picked my loads from the latest Woodleigh manual. Both PP projectiles.

 

[wswolf]

I have been using Reloader-15 for my 358 Norma and 416 Taylor belted magnums. Just wondering if there might be a better choice?

In my .358 Norma Reloder 15 worked well with 225 gn bullets but accuracy was poor with 250 gn. The best results with 250, 280 and 310 gn bullets came with H4350 with IMR4451 a close second. Big Game looks promising with 250 gn but I have not finished working up loads. Big Game is quite dense so you might be able to get enough into a .416 Taylor case to get decent velocity.

 

[Boyd Brooks]

In my .358 Norma Reloder 15 worked well with 225 gn bullets but accuracy was poor with 250 gn. The best results with 250, 280 and 310 gn bullets came with H4350 with IMR4451 a close second. Big Game looks promising with 250 gn but I have not finished working up loads. Big Game is quite dense so you might be able to get enough into a .416 Taylor case to get decent velocity.

. I was looking around the net but could not fined any data for Ramshot Powders for the 358 or the 416. Reloading components do not have a reliable supply in my area. I have seen H4350 at my local supply store.

 

[wswolf]

I am not aware of any published Ramshot data for either cartridge. They do not appear in the new Western Powders Loading Guide.
In my .358 Norma with a 24 inch barrel (Federal 215 primers) I worked up to 70 gn of Big Game with a 250 gn Nosler Partition for a little over 2700 fps and an excellent group. More testing will be necessary and I suspect that slightly higher velocity is possible. Using H4350 with the same bullet 2800 fps should, in my opinion, be considered maximum. I would start working up with about 73 gn and not exceed 78 gn. IMR4350 would also be a good choice. Data is available from Nosler, Hornady and Speer.

The only data for the .416 Taylor that I have seen is in magazine articles by Ken Waters, Bob Hagel and John Wooters. They all liked IMR4320. Since Ramshot Big Game is slower burning (at least according to the charts) it would probably be safe to begin with the starting loads for 4320. Powder burning rates vary with different cartridges so burning rate charts are guidelines and should not be considered accurate. Proceed with caution if you proceed at all.

Cheers,
Walt

 

[Boyd Brooks]

I am not aware of any published Ramshot data for either cartridge. They do not appear in the new Western Powders Loading Guide.
In my .358 Norma with a 24 inch barrel (Federal 215 primers) I worked up to 70 gn of Big Game with a 250 gn Nosler Partition for a little over 2700 fps and an excellent group. More testing will be necessary and I suspect that slightly higher velocity is possible. Using H4350 with the same bullet 2800 fps should, in my opinion, be considered maximum. I would start working up with about 73 gn and not exceed 78 gn. IMR4350 would also be a good choice. Data is available from Nosler, Hornady and Speer.

The only data for the .416 Taylor that I have seen is in magazine articles by Ken Waters, Bob Hagel and John Wooters. They all liked IMR4320. Since Ramshot Big Game is slower burning (at least according to the charts) it would probably be safe to begin with the starting loads for 4320. Powder burning rates vary with different cartridges so burning rate charts are guidelines and should not be considered accurate. Proceed with caution if you proceed at all.

Cheers,
Walt

Thanks Walt,
I am not confident enough yet to work up my own loads from scratch, have only started with a published load and tweaked it, but never exceeding listed MAX'S. The Wooliegh manual has a section on 416 Taylor, that's where I got my starting info.

 

[Shootist43]

Dittos on the H4350 being a good powder for both calibers.

 

[Pheroze]

Have used both Varget and H4350. Both are good.

The Woodleigh manual has the most accurate published loads/velocity in my experience. It's a very reliable source.