Load data-300wsm and 308 win.

[Casefull]

The following load data is from experimentation and is unsafe...do not use this data:
300wsm 24in barrel
60g varget, 150 sierra, 3219 fps
68.1 rl17 150 barnes, 3386 fps
73g superformance, 150 ttsx, 3428 fps
69.3g superformance, 180 ttsx, 3111 fps


308 win 24in barrel
hornady superformance factory ammo 150g sst, 3002 fps
51.3 powder from above factory round reloaded in my 308 case
with 150g sierra bullet, 2863 fps (interesting in the loss of vel)
51.2g superformance powder, 150g sierra, 2574 fps
49g rl15, 150g, 2937 fps
46.5g varget, 150g, 2882 fps
48,2g varget, 150g, 2869 fps

I was amazed at the velocity of the 150sst factory round...I need to see how they group.
I was also surprised with the rl 15 and I am going to work on that load for my 308 as I have been hunting with varget.
The rl 17 and superformance both give good vel in the wsm...I also need to see which groups better. Hornady obviously does something different on the sst load to get 3000fps.

 

[Offfhand]

Two questions: How do you know it is unsafe? And if it is unsafe why did you list it?

 

[Casefull]

Just my way of saying I am not responsible for those loads. They worked fine in my rifles but that may not be so for another shooter. I can only measure my own powder.

I am sure someone on the forum can advise me on how I should communicate said info.

 

[steve4102]

hornady superformance factory ammo 150g sst, 3002 fps

Don't know how many rounds you tested or how far your Chrony was from the muzzle, but I would say this is a Chrony error as Hornady lists this round at 2772fps.

51.3 powder from above factory round reloaded in my 308 case
with 150g sierra bullet, 2863 fps (interesting in the loss of vel)

Does this mean you pulled the factory round apart, put the powder in another case and seated a different bullet? I'm not sure this is a good idea with this type of ammo.

I do not know how Hornady "blends" their propellants in their Superformance Ammunition, but if it is stacked or layered in the case, then pulling a round apart and re-using the powder may be a recipe for disaster. Or not?

From Hornady on Superformance ammo.

By blending propellants and manipulating burn rates, we have been able to obtain velocities that were never before attainable in conventional centerfire rifle cartridges.

51.2g superformance powder, 150g sierra, 2574 fps

Where did you get data for this powder bullet combo? Hodgdon does not list Superformance in any 308 loading data. I can't find any at the moment, but I do believe there have been conversations with both Hornady and Hodgdon posted on the Superformance Powder/ Ammo connection. Just because it says, "Superformance" on the ammo box does not mean that it is Loaded with "Superformance" powder.

Superformance powder has a burn rate slower than 4831, much to slow for the 308 Win. That is why we see no data for this powder in the 308 or the 223 , yet we see Hornady Superformance Ammo in both.

Pulling a factory round and assuming you know what the exact powder is/was, may not be such a good idea.

 

[Casefull]

Don't know how many rounds you tested or how far your Chrony was from the muzzle, but I would say this is a Chrony error as Hornady lists this round at 2772fps

2772 is actually the velocity at 100yds. It is 3,000 fps at the muzzle so my Chrony is right on at 3002fps. Kind of amazing for a 308 right? They obviously layer the powder in the factory loads which is why I tried it on another cartridge. Most of the inventions in the last century would not have occurred if someone had not tried something. If all you do is read it in a book or online then you will only know what others know. I only posted this info for someone doing load work on these rounds...thanks for the warnings...there are some who would look at the info and say "that is interesting" or "I already know that" and then the guy who says "you are wrong and here is why...pulls out his rule book" Let us go back to blackpowder days, nice safe low pressure loads, safe velocity like 1400 fps, be safe and follow.