Anyone use Magnum powder in their 300WM?

S

Six Pack

New member
I've tried four different powders with 180g Nosler Accubonds and it is the best so far. Problem is that I can't get a straight answer from Ramshot. I pointed out what I believe is a mistake in their load data, had likely confirmation from Nosler and get a nonsense answer.

Here's the details...max per Ramshot with 180 Nosler Balistic Tip is 86.0 g. Max with 180 Partition is 83.6 g. I asked them if I could use the BT info for the Accubond and was told, "no, you need to use the Partition data". So, I load to 84.0g with no sign of pressured whatsoever. At this point, I noticed their data for the 200g Partition is 84.4g of Magnum. Nosler agreed this "sounds backward". I contacted Ramshot again to point out the issue and was told, "just load to our velocity and you'll match the max pressure". No questions about barrel length, seating depth, etc. Does this sound right to you?!?!

Regardless, At 82g, Magnum is always .5 to .7 MOA in my rifle but I suspect there is a sweet spot closer to the true max load that will get me over 3000fps.

I'm stumped. Anybody use this powder and willing to share your experience and/or wisdom?
 
With differences in the materials and construction of bullets I would defer to the bullet manufacturers load data. Comparing the loads for different bullets is always a gamble because you have no idea what the differences are.
Is the published data the true maximum for all rifles in all brass under all conditions? No! It is a guide for safe loading. Taking it beyond that point may or may not be safe with your components and rifle.

I don't have the equipment to measure the pressure time curve of the load I am firing, the guys who do the factory load workup do. The first indication of a pressure problem might be a primer pocket that gets loose after loading a piece of brass a few times. The point is you have no idea what the pressures are in your rifle with any given load.
 
"...told, "no, you need to use the Partition data"..." Um, soft of. Western will tell you that for liability reasons.
Also matters if you're using the same barrel length as they did(a 24", 1 in 10) for their tests(that very likely was in a Universal receiver) and think you'll get the same velocities as they did when all that will change according to the conditions.
The bullet weights were probably tested on different days under slightly different climatic conditions. That alone will produce the slight differences. Anyway, normally, you load for the bullet weight and the construction or brand makes no difference.
"...defer to the bullet manufacturers load data..." Powder maker's. Who made the bullet doesn't matter. Why Western lists so any bullets of the same weight is known only to them. If you read a Lyman book, they give the weight only.
 
T. O'Heir,
The Lyman manual lists the bullet make and type of bullets that are used at the beginning of the data pages under "Test Components".

Try loading a solid bronze bullet with data for a cup and core bullet data and you will likely ruin your gun and the whole weekend. The materials and construction of a bullet matters. That is why bullet manufacturers spend the time and money to work up loads for their bullets. Ignoring that is dangerous but advising other to ignore it is irresponsible at the least.
 
ShootistPRS, I understand and appreciate your comments. I have been loading for 40+ years and try to defer to the bullet manufacturer data but in this case, they have not tested Magnum powder with the 180 Accubonds or Partition. I am loading the Accubonds but noticed what I believe to be an error in their data. What caught my attention was the clear discrepancy between the 180 Partition and the 200 Partition. Further, I brought the similarities of the Balistic Tip and the Accubonds to their attention. Ramshot has not tested the Accubond so I suspect they are suggesting their Partition data as a CYA. Personally, I think telling someone, "just load to our velocity and that will match the pressure" is incredibly irresponsible.....especially when they never asked anything about the rifle, barrel length, seating depth, COAL, etc. and BTW, it is a Model 70 Extreme Weather with a 26" barrel. All other components matched the load data. I STRONGLY SUSPECT the actual safe max load is close to that of the Balistic Tip since the only real difference is that one is bonded and the other is not. The bullet profile is virtually the same.
 
Six Pack,
I understand your concerns over the data. Like you I have run into data conflicts in the past. I too called the bullet manufacturer to find out. I had a great discussion with one of their ballisticians and found out that the reason for the change was a change in the SAAMI specs for the caliber. After explaining my situation and the details of my gun I was told that the older, higher pressure loads were fine in my case. I was also told that they would deny ever telling me that if something bad happened.

I am concerned for your safety but more so for the safety of new loaders who might make similar decisions based on a thread like this. You obviously have a great deal of experience and pay attention to the details where a new reloader might not. We all know that "if it's on the internet it is gospel" is practically never true. I am just doing my best to generate good habits in new reloaders for their health and the good of the sport.
 
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