Your most accurate powders?

[shooting on a shoestring]

What do you mean "accurate powder"?

I find there are 3 types of "accuracy". And I'm talking revolver cartridges here. That's mostly what I shoot.

1) How consistently does the powder drop from my measure, or what is the weight difference from drop to drop?

2) What is the velocity difference due to powder position in the cartridge?

3) What is the size of the bench rested group?

Small aside: The 3 points above deal only with precision (repeatability), not accuracy (point of impact being the same as point of aim).

I find ball type powders (HP38, HS6, W296, AA#7, Lil'Gun, TiteGroup ect...) to meter really well, very repeatable throws. But they are also very position sensitive (150 fps with HS6 and W296 in .357 and .45Colt). But for target shooting with the barrel remaining horizontal, the position of the powder stays pretty constant (on the bottom side of the case). Groups can look OK. However, in hunting or CCW, drawing a handgun from vertical, the first shot has the powder near the bullet, and shows considerably lower velocity, different point of impact.

The least position sensitive powders I've found in .357 and .45Colt are Bullseye and 700-X. They show about 15 to 20 fps difference from powder at the primer, to powder at the bullet. (I usually use Bullseye in the .357 snubby for 148 WC and 158 SWC at 1000 fps. Bullseye in the .45Colt BH 7.5" 255 SWC 1000 fps.) Also these are very low charge weight powders, hence cheap to use.

Unique meters less well than Bullseye, is considerably more position sensitve (80 to 100 fps in .357 and .45 Colt) and uses slightly heavier charges for the same velocity.

H4227 gives my .357 & .45Colt great groups, cases are full of powder, so it can't get away from the primers, also high end in velocity, and high cost due to large charge weights,(roughly 3 times the weight of Bullseye charges). Also it meters well, about +/- 0.2 gr on a 23 gr charge.

So what's an accurate powder? Depends. If you can be happy with 1000 fps or less, Bullseye or 700-X are really great. If you have to get in the 1300s, H4227 is super (I do like Lil'Gun and H110/W296 alot). If you're going for something in between, plan on your velocity varying about 100 fps depending on where the powder is positioned when you pull the trigger.

If you need more accuracy or velocity, use a rifle.

 

[Scooter72]

.357 Magnum = H110
.38 Special = Tite Group
.40 S&W = Power Pistol

 

[Ben Shepherd]

SOS:

I'm talking accuracy on target here.

As for the powder position thing:
I try to fill my cases to 90+ percent. That way powder posistion issues are solved, and a double charge is impossible.

Could I build loads that are cheaper? Sure. But I like the above method BECAUSE it eliminates those two variables.

 

[shooting on a shoestring]

Ben:

I hear you. Its not always about the cheapest shot. As for 90% loadings getting around powder position, I got suprised by Lil'Gun and W296/H110. I suposed they would not be position sensitive b/c they did fill up my cases to what I estimate to be at least 90% full after the bullets were seated. I saw velocity drop about 100 fps when I pointed the barrel down before firing. However, I still get 2 to 3 inch groups at 25 yds bench rested shooting with the barrel remaining horizontal. So now I have another point to investigate. How will my groups be affected if I fire six shots on paper with 3 having the barrel pointed down before firing and 3 pointed up first. I regularly do this drill over my chronograph just looking at velocity, but haven't done it on paper to check variation in group size. Time to empty some Bullseye loads and fill them up with H110.

 

[THE DOC 44]

Most accurate powder

After trying most of the U.S. and European powders the most accurate line of powders are those made by Vectan . They are easily metered , clean burning and give excellent groups on target , and somehow the recoil seems to be more polite .