High velocity rounds vs low with peeps

[Hogstir]

I purchased a BBS Carbine in 45 Colt a while back and installed Skinner sights front and rear.
I intended to use it mainly as a camp or brush walking gun with heavy loads as we do have both bear and mountain lion in the areas I camp and hike.
Using 265g LFNGC bullets at 1620fps the rear sights set at 1.5 turns from the lowest position and the front sight that Skinner recommended the sights are right on at 50 yards.
I decided to load up some lower velocity rounds (1000fps) for plinking and target.
To my surprise the lower velocity rounds group 4 inches higher at 50 yards that the high velocity rounds. This seems backwards to me. Shouldn't the low velocity rounds group LOWER?
I don't have enough adjustment to lower the rear sight enough to zero with these rounds.
Does this mean I need a TALLER front sight?

[North Country Gal]

What weight bullets on the LV rounds? Bullet weight will also make a difference.

Yes, a taller front sight will lower POI.

[Petey]

The bullet is still rising at the lower velocity......... Faster = flatter . The rise takes place over a greater distance.
Find a trajectory calculator.
The graph should help you visualize what I'm trying to explain.
https://www.shootersforum.com/attachmen ... icking.jpg
Enjoy that Henry & Happy Shootin!
Petey

[Hogstir]

Ah, mystery explained.
Northern country gal I was using the same bullets at a lower powder charge.
So I need to get a taller front sight.

[DAVIDF]

The effect of recoil changes the trajectory of the slower moving bullet more than the faster even though the recoil is less with the slower velocity loads. For example, with two loads using the same bullet but at different velocities, the slower load will print higher because the bullet takes longer to leave the muzzle and due to recoil the barrel is higher or point of aim higher by the time the bullet exits the barrel. At longer distances the slower load will drop more and poi will be lower as shown in the trajectory calculator that Petey posted.

[RetiredSeabee]

Ah, mystery explained.
Northern country gal I was using the same bullets at a lower powder charge.
So I need to get a taller front sight.

Or you could remember to change your point of aim with the low velocity.
If your primary load will be the high velocity and you are sighted in for them.