Working up loads

[abunaitoo]

I like to play with loads.
Different powders, boolets, weights.......
I was thinking the other day (bad for me) about boolets stabilizing at different speeds.
Might just be thinking bubbles, but see what you think....

With light, fast burning powder. It kind of kicks the boolet out of the barrel, at a slow speed, and it's just lobbing it along.
I've found this works best with heavy boolets.
Works great, but you have to move the sight to shoot farther.
I'd like it to shoot POA at 50yds and 100yds.
Like with high power jacket bullets.
When I try to increase the charge, with cast boolets, the higher is gets, it reaches a point that the groups start to open up.
My thinking is it's going to fast for what the boolet is made for.
I can get it to hit center at 50/100yds, without moving the sights, but accuracy is not what it is with a lighter load.

I've been playing with a 2A for a little while.
I noticed that, at 100yds, the groups did open up as the charge got higher, but they all grouped to the left.
I just thought the sights were off, and so I didn't move it.
Funny thing is it's dead on at 50yds. Sometimes 5 shots touching.
Are the boolets just not stabilizing at 100yds because their not going fast enough????
Kind of like throwing a baseball. The correct speed, and it's a curve ball. Faster and it's a fast ball.
With this thinking, could the load just be slow enough to be curving the boolet.
If I speed it up, might it stabilize and go straight?????

[country gent]

The biggest share of the garands were zeroed at 12 yds if I remember correctly for the 200yd zeros. THis was done at 12 yds with the bullet on the way up the trajectory path and then back on the way down at 200 it again was zeroed. This can be done with cast boolits also finding the 2 intersection points in the trajectory. I suspect the 03s, M! $s, and possibly the M16s were done the same at certain range points. The shorter range is easier to have and maintain in a area, and qualified shooters to zero rifles are easier to train at the closer ranges than the full distance. At one time the military had the thermometer target for this it was a aiming point down low on the paper then a line up the center with cross marks for 200 300 500 600 700 800 900 and 1000yds this target was set for the M118 ball ammo at 25 yds.

[WRideout]

In army basic training, ca. 1972 we used a Canadian Bull target which did exactly what Country Gent described, except that it rather resembled an upside down "u". While aiming at the black target at about 25 yards, the bullet strikes were down in the open part of the "u".

But back to the original question, It does seem like velocity affects stability in flight. My Jap type 38 was all over the paper with light loads of pistol powder, but tightened up with bigger charges of rifle powder that increased velocity. Also, barrel twist seems to affect all that as well.

Wayne

[rintinglen]

In the Marine Corps in the early seventies, Battle Sight zero was set at the "1,000 inch range." An M-16A1 sighted in with the issue M-193 ammo would then have a Point blank range (on a Man sized target ) of 274 meters. At least, that's how I remember it.