Water Swatter

What do you all use for an accurate powder measure?
When working up a load do you jump up in 5 gr increments or 10, or since it is a volume measurement is 5 gr to hard to measure or worth the effort?
What is your procedure for working up a load?
Do you start with a powder and shoot several different bullets to find the most accurate bullet and tune thepowder from there?
Do you start with a bullet and try different powders until one looks promissing?
When do you start trying different primers / primer substitutes (variflame, 25acp conversion Kit)

I just received my VariFlame primer kit on Friday and I am anxious for my encore barrel to return from TC so I can start working up a target load and a hunting load.

Roskoe

To be honest, I usually jump up or down in 10 grain increments. You don't often hear of a MZ load calling for 78.4 gr of powder, like you do in CF reloading. I use a Traditions brass volumetric powder measure. I have alsotried calculating volume to weight conversion factors; and weighing charges at home on a powder scale - putting them in small containers to be used later at the range.This appeared to be a waste of time.

Like many on this board, I have burned up a lot of powder and bullets playing around with loads. I see you are shooting an Encore. If you want a magnum class hunting load, I wouldtry either 130 gr. of Pyrodex pellets or 130 gr. of 2F Jim Shockey Gold. Since you are from Colorado, I'm assuming you plan to hunt during the MZ season and will want to use the loose powder. As far as bullets go, the 250 Shockwave is hard to beat as a "go to" bullet. But in Colorado, that won't fly. Try the 338 gr. Platinum Powerbelt. In answer to your question, I usually start with a bullet and try all the appropriate powder charges rather than vice versa. I have not, so far, found primers to make a big difference. The 209's made for MZ rifles, though,seem to group a little better and have a lower SD of velocity.

For target shooting, charges in the 70 to 100 gr. level are usually going to be your best bet. This is where the fine tuning of load development can really pay off. Often, powders like Goex, 777,or loose Pyrodex produce the best groups at these velocities. There are other variables - like swabbing, seating pressure, and even QLA concentricity - that can make asignificant difference in group size. Some folks I know use nothing but two 50 gr. Pyrodex pellets for accuracy testing. Everything else becomes a "variable". And, to some degree, each gun is its own little DNA molecule when it comes to what it likes or doesn't like.

WiseWood

A corect measurement sounds like a picky to me ... What is everyone 's belief to meet thier MZ from powder measuring accuracy of + 1,2,3,4,5, or 10 grains ???? what kind of tool for measurement scale most use ?

yeoman

Good questions all. You should probably set a goal. It's generally recommended you move in 10 grain increments in 50 cal., 5 grain in 45 cal. It's also recommended you begin with 60% of maximum charge and work up from there, minimum 3 shots per round, and keep track of the results by marking/removing targets. Your gun is probably rated for 150 gr. max, so you might start at 90, then 100,110 etc. with a given bullet and powder. The difficulty comes in the shear numbers of combinations. You may start with a 250 gr bullet and find the gun is most accurate with 110 grains of Pyrodex at 100 yds., but that bullet may be available in 195, 230, 250, 270, 300 grains, and until you've tried them all, no one can tell you what your gun will like. Then the powder; Pyrodex, Goex, 777, Kswiss etc...Oh yeah, then the ignition. Clean barrel or fouled? Swab or no between shots? More moving parts than you can try out in a lifetime and more choices every year. I, for one, am merely seeking the heaviest bullet I can send down range with deer killing power at 100 yds. and place 6 of 6 on a 6 inch target, every time. Ease of loading is in my mix, and I'm only working through Pyrodex now. If I get there, which I think I will, I'll try other powders and try to raise the bar, but no way I'm bringing another rifle into the mix!

lemoyne

I think you will find that a good sabot gun will often shoot a wide range and varity of bullets if you have sabots that fit the barrel well. I usually use the Greenhill formula to determine a little bit about which bullet will work good and what percentage of the bullet weight I should use to pick a starting point for the powder load.
I will go in both directions from that point in 10 grain increments. Once I find the 10 grain load which shoots best I try 5 gr each way to see if there is a better load. I often find that a bullet will have two loads one light and one heavy that will shoot good. Lee

yeoman

Lee, what's the "Greenhill formula"?

outdoorslover

I ususally find the most accurate bullet---300 grain XTP for me and then find the most accurate powder charge.I only work in 10 grain increments.

You are very likely to get great accuracy with the 250 or 300 grain SW or XTP Mag. Try those out!

lemoyne

Greenhill Formula that, while it was designed for estimating twists for boat tailed lead core bullets of moderate velocity, does a pretty good job of estimating twist required for flat based bullets under "normal" conditions.
T = Twist in inches
K = Greenhill's constant = 150 (This has to do with the specific gravity of a jacketed lead bullet)
D = Bullet diameter in inches
L = Bullet length in inches
T = (K * D2) / L
[K = Greenhill's constant = 150 X Dia. X Dia.] divide by length of bullet.
There are free ware programs available which make it real simple I have one I picked up some where. Lee

yeoman

Lee,

So basically, based on the formula, the longer the bullet relative to its length, the faster the twist. Solving for a .45 round ball, gives a twist of 1:67.5.

Thanks for that!