Help me understand

[test drive]

several months ago I picked up a Uberti Schofield in .45 Colt .
When I got it I had 3 boxes of shells. 1 box Winchester fmj. 250 grn , 1box factory cowboy loads 250 grn flat lead nose and 1 box factory cowboy load 200 grn lead flat nose.
No matter what I tried it always shot about 3 inch high and about 2.5 inch to the right.
So I recently hand loaded one box. I used hand casted .250 grn lead flat nose whith
.7 grn Universal powder. With those loads the windage was dead on at 10 and 15 yards
Still 3 inch high but I can live with that. Now I understand how different loads can affect
High and low but that much windage ? I am not a great re-loader by no means, I can do a little hand loading with my Lee hand loading set but that’s as far as I get. So different loads can affect windage that much ? How ?

 

[Obturation]

I'm not an expert but my understanding of it is barrel harmonics, which way the barrel is flexing at the time the projectile exits. Other factors too I'm sure and I could be wrong but that'a what I was told.

 

[gunlaw]

If you are that high at 10 try 25 yards. That will tell you something about how the sights are regulated.

 

[mokin]

I was shooting next to a gentleman who was developing some loads. The rifle was fairly new to him. He had a couple of loads that on paper produced the same velocity with different powders. He shot one group with one load, then, without changing the dope on his scope, shot the other load at another bullseye. We walked down to check our targets. He had two very nice groups, roughly the same elevation, but close to three inches different in windage. Neither of us had seen anything that drastic. It happens. Barrel harmonics are all we could come up with.

 

[PO2Hammer]

Handguns start to twist and rise in the hand while the bullet is still in the bore. Big bore six-guns especially. Point of impact varies depending on bullet weight and speed.
For me (shoot righty) slower bullets shoot left-er.

 

[tightgroup tiger]

Handguns start to twist and rise in the hand while the bullet is still in the bore.

Especially with heavy, slow moving bullets. Your finger position on the trigger means a lot to.

 

[PO2Hammer]

If anyone remembers Elmer Keith, he wrote a great book on all aspects of big bore shooting and reloading.
'Sixguns' by Keith is worth a read, especially if you like loading and shooting big bore single actions.