Hello
I am currently using US869 in my 7mm STW. I don't know what kind of velocity I am getting. It's a clean burning powder but accuracy sucks. Has anyone else used this power? I was told that spherical powders are more efficient in burning the full charge. Any thoughts would be appreciated.

I'd try Retumbo or RL-25 in that case.

In my old 7 RUM, Retumbo was the powder

quote:

I was told that spherical powders are more efficient in burning the full charge.

There's nothing wrong with "spherical" powders, but don't listen to everything you're told.


Also, don't bother to handload for a cartridge like the 7mm STW or RUM unless you own or have access to a chronograph. And don't bother to shoot a 7mm STW or RUM unless you handload.

You don't mention what weight bullet you are using or attempting to use. That makes a lot of difference in which powder will be appropriate. A powder as fast as Retumbo or RL-25 will do for a 140 grainer or under, but 160-175 grain bullets need a powder like surplus WC-872 or US 869.

Remember, the powder is only one factor in accuracy and is usually not the most significant, so don't blame your problems on the powder until you've investigated all of the other variables.

If anything, a spherical or ball powder, especially large charges, is MORE diff to ignite & often requires a mag primer. I shoot a 7mmDakota, very close to the STW. I like IMR7828 in mine w/ all bullet wts.

Bighorn:

You are shooting a large charge, of a hard to ignite powder. It takes a really hot primer.

The only primer my STW will group well with when using a ball powder is Fed 215's.

Thanks for the answers so far. I have a chroniy on orer from Natchezes. I am shooting 160 gr Nosler Accubonds. Retumbo or H1000 was next. US 869 was recomend by Hodgdon.

In mine I have been shooting some factory Federal 150gr Nosler Solid Bases. I know their factory but they shot so darn well and I got 15 boxes for only about $12 per box so I couldn't hardly pass on them.

With what I HAVE loaded, I have found H-1000, and RL-25 to both give good velocity and accuracy for the 150 and 160gr bullets.

I also am only using the Fed 251M primers. These will light off, if not, just about any powder you care to shove off in these big cases.

There are a couple of surplus powders out there that I have tried as well and they shoot well but you have to work up accordingly, as there is no qualified data with them. They are pull down or new surplus powders for the 50 Cal. One I have used the most is 872, which is REALLY a bit slow for even this round, another is 860 which is just a tad slower than H-869, depending on which lot you get. There are a couple of lots of each out there and plenty of folks shooting it.

As mentioned use your chrono when you get it but also stick with looking for a tight group.

Good luck, and let us know how it works out for you.

quote:

Originally posted by BighornBreath:
I have a chroniy on orer from Natchezes.

Total waste of money. It doesn't tell you spit about the Pressure and once you attain good Accuracy(with Powders designed for it) the Velocity will be fine whatever it is.

quote:

I am shooting 160 gr Nosler Accubonds. Retumbo or H1000 was next. US 869 was recomend by Hodgdon.

Those are the Powders you should be using. My "guess" is the Retumbo will be the winner. I use a whole bunch of H1000 in a regular 7mmRemMag, and since the 7mmSTW has more capacity, I'd be trying the slightly Slower Retumbo in it.

Good Hunting and clean 1-shot Kills.