Point of impact question

[steelerfan]

A friend gave me 2 boxes of Aguila 22lr ammo to try, 1 box of Supermaximum High Velocity & 1 box of Super Extra subsonic.
I was shooting with a Savage bolt action that is a tack driver at 50 yds., I shot some Federal & Remington first to check zero, all is well, real tight groups & right on target.
Shot the high velocity first, good groups but all about 10"-12" high, also wouldn't extract, I had to remove each casing by hand.
Shot the subsonic next, good groups but all about 3"-4" high, although extraction was good.
Went back to my other ammo & still right on the mark.
The Federal was 40 a grain bullet with muz vel of 1240 fps
Aguila high velocity was a 30 grain bullet with a muz vel of 1700
Aguila subsonic was 38 grain bullet with a muz vel of 1025

Any thought as to why this happened ?

[dkf]

The bullet flys in an arc due to muzzle being elevated and gravity. There are some other factors as well obviously.

Are those velocity numbers chrono numbers from your rifle or are they box velocity numbers? I would bet the 38gr Aquila and the 40gr Federal are fairly close in velocity, the 38gr may even be a bit faster.

[steelerfan]

The bullet flys in an arc due to muzzle being elevated and gravity. There are some other factors as well obviously.

Are those velocity numbers chrono numbers from your rifle or are they box velocity numbers? I would bet the 38gr Aquila and the 40gr Federal are fairly close in velocity, the 38gr may even be a bit faster.

The numbers are from the box, I realize the high velocity is quite a bit higher than the others but would it affect point of impact that much at 50 yds ?

[DavidTM]

A friend gave me 2 boxes of Aguila 22lr ammo to try, 1 box of Supermaximum High Velocity & 1 box of Super Extra subsonic.
I was shooting with a Savage bolt action that is a tack driver at 50 yds., I shot some Federal & Remington first to check zero, all is well, real tight groups & right on target.
Shot the high velocity first, good groups but all about 10"-12" high, also wouldn't extract, I had to remove each casing by hand.
Shot the subsonic next, good groups but all about 3"-4" high, although extraction was good.
Went back to my other ammo & still right on the mark.
The Federal was 40 a grain bullet with muz vel of 1240 fps
Aguila high velocity was a 30 grain bullet with a muz vel of 1700
Aguila subsonic was 38 grain bullet with a muz vel of 1025

Any thought as to why this happened ?

The numbers are from the box, I realize the high velocity is quite a bit higher than the others but would it affect point of impact that much at 50 yds ?

Yes.

#1-- The "Supermax" ammo @ 1700fps has a lot more powder in it to get it to that higher velocity and thus, it will expand the little 22 brass case bigger (more pressure) than either of the other two types of ammo. This will also shoot higher than the other as it is traveling almost 500fps faster than the next rated ammo.

#2-- The Sub-sonic didn't "stick" because it wasn't loaded to the max with powder. Now, I haven't looked at the bullet structure or how much of the bullet actually contacts the lands & groves, but just to guess I would bet the 38gr has less contact with your barrel than your 40gr. Federal.

FWIW

Dave

[Twoboxer]

You were surprised that the Hi-V bullets were SO high at 50yds, and the Lo-V bullets were ALSO high at 50 yards compared to your reference rounds. You expected the Hi-V to be a tad high, and the Lo-V a tad low.

I suspect what happened is the two new cartridges pushed their bullets out of the muzzle at a different point in the barrel's vibration cycle, in these cases launching the bullets on a higher trajectory.

[steelerfan]

Yes.

#1-- The "Supermax" ammo @ 1700fps has a lot more powder in it to get it to that higher velocity and thus, it will expand the little 22 brass case bigger (more pressure) than either of the other two types of ammo. This will also shoot higher than the other as it is traveling almost 500fps faster than the next rated ammo.

#2-- The Sub-sonic didn't "stick" because it wasn't loaded to the max with powder. Now, I haven't looked at the bullet structure or how much of the bullet actually contacts the lands & groves, but just to guess I would bet the 38gr has less contact with your barrel than your 40gr. Federal.

FWIW

Dave

I had a feeling that's why the brass wouldn't extract, I'm glad I tried it with my bolt action instead of my semi-auto. I also figured it would be a little higher, just not that much. Thanks for the info, I've never experienced this to this extent with ammo before, very interesting

You were surprised that the Hi-V bullets were SO high at 50yds, and the Lo-V bullets were ALSO high at 50 yards compared to your reference rounds. You expected the Hi-V to be a tad high, and the Lo-V a tad low.

I suspect what happened is the two new cartridges pushed their bullets out of the muzzle at a different point in the barrel's vibration cycle, in these cases launching the bullets on a higher trajectory.

Yes, I was surprised, & your info is very interesting as well, I may try this in one of my other rifles & see what happens, thanks

[Twoboxer]

Doing load development for other rifle calibers you can see the same sorts of things happening. While doing a ladder test using "identical" components and gradually increasing the powder charge, you can see POI "Height" on the target sometimes decrease even with higher velocity than the previous shot. Or see velocity the same pr lower even with more powder.

In your case, there are lots of different components in your various factory rounds. It's somewhat amazing that your federal and Remingtons share a POI at 100 yards

[steelerfan]

Doing load development for other rifle calibers you can see the same sorts of things happening. While doing a ladder test using "identical" components and gradually increasing the powder charge, you can see POI "Height" on the target sometimes decrease even with higher velocity than the previous shot. Or see velocity the same pr lower even with more powder.

In your case, there are lots of different components in your various factory rounds. It's somewhat amazing that your federal and Remingtons share a POI at 100 yards

It's actually at 50 yds., & while POI isn't EXACTLY the same it's really close, close enough that I don't have to change my scope adjustments