Confused about powder weights.

[stainless1911]

I was getting ready to load some .40 with WST powder and Hornady JHP when I noticed something strange in the powder weights.

I am about to order the Lee mold which comes in at 175 gr, and with the WST powder, the Lyman book says to use 5.1gr min, and 5.7gr. max, but with the much lighter 155gr, JHP round, its calling for a 5.5gr. min, and 6.4gr. max.

Why do they want a higher load on a lighter bullet? And why, if the max load on the one bullet is 5.7gr, do they say its ok to put 6.4gr in another round? Wouldn't that put you way over max?

The other question I have is that I'm having trouble getting consistent throws, or perhaps its the scale. I'm using the Lyman #55 powder measure, and the Lyman 1000XP digital scale. They are both new. The measure is bone dry, no oil, I washed it very thoroughly twice. There aren't any fluorescent lights to bother the scale, and I calibrated it according to the directions. However I'm getting differences from one charge to the next of up to .5gr. I'm concerned that I will inadvertently charge over max while loading large #'s of rounds. I'm only loading .40 right now, and with weights ranging from 5.1 min to 5.7 max, having a variation of .5gr, is unacceptable. One load could be below minimum, the next above maximum.

[hawcer]

The heavier the bullet ,the more pressure you will have...plus sometimes they are seated deeper into the case. So...heavier bullets will always require less powder. NEVER use the charges for a light weight bullet when using a heavier one.

If you are throwing a .5gr difference... and you only have a .6gr window between min and max, set it to throw light and trickle the rest...it takes longer, but is the safest way.

Also look to other manuals...and compare. Since you are using WST...Hodgdon.com's reloading data would be a great tool for you.

One other note. WST is a great target powder, this is what I use in my 45acp's...not so good for defensive rounds. You might look into something else to load up your HP's with. Unique would be a good choice to try out.

[stainless1911]

Why wouldnt WST be a good defensive round powder if its accurate enough for target rounds? Please remember that Im a new-b, andt this seems to be contradictory.

[hawcer]

Not in all cases...but usually. Faster powders like WST, bullseye, titegroup, ect , while maybe gaining in accuracy...you usually loose in velocity.  hollow point bullets like the xtp require higher velocities to fully expand. Don't get me wrong...you can still load them up with WST and shoot them at targets all day. But to gain the maximum effectiveness of a expanding bullet... there are other powders that are better suited for the task.

[stainless1911]

Oh. Thanks very much, youve always been a good help to me.

What about the inconsistency's though? I thought that the Lyman measure was a good one. I was hoping this was an error on my part. It would take forever and a day to weigh and trickle a thousand rounds. Once I get the casting equipment, and decide on a charge weight, Ill be loading the 2000 emptys that Ive collected..

[Mohunter]

Not in all cases...but usually. Faster powders like WST, bullseye, titegroup, ect , while maybe gaining in accuracy...you usually loose in velocity.  hollow point bullets like the xtp require higher velocities to fully expand. Don't get me wrong...you can still load them up with WST and shoot them at targets all day. But to gain the maximum effectiveness of a expanding bullet... there are other powders that are better suited for the task.

+1 on all of Hawcer's advice.
I would also like to add that for the .40 calibers you may want to take a look at Blue Dot for your XTP's. Blue Dot is used for magnum type loads and it worked really well for my 10mm and 180gr. XTP's. I think you will find the velocities that you require by using Blue Dot.
Alliant's website has all the data you would need for Blue Dot.
Look Here--> http://www.alliantpowder.com/default.aspx
Just click on "Reloading Guide" and follow the prompts. Or click on products, then click on Blue Dot, and click on all recipes. You will get the data for lots of different weight bullets, calibers, ect.

[XbonesX]

I had the Lyman 1500 XP digital scale and it was HORRIBLE. I returned it. my guess is it is the scale.

but we'll give them the benefit of the doubt and the scale is just fine, then wind or a breeze is the biggest problem with digital scales. being that its 90 degrees in most places right now I am assuming the AC is running if your reloading in the house, or maybe you have a garage door open, or a door to the outside.