New ACP hits low

[Jettubby]

I used to have the same problem until I got traning and fixed it:

http://bullseyepistol.com/training.htm

[stevomills]

Im going to assume that your shots at 25 yards are 6" low and a little left. If they are low left and right I would think something could be wrong with the pistol or It very well could be the ammo you are using. If most of your shots are low 6" and left even just a little left off of center, I will alomst promice you are altering the sights before the load had left the tip.

[Haizum]

Originally Posted by raynor

What bullet weight are you shooting, in mine 200's are dead on and 230's hit a couple inches high. That's at 50 feet.

All other things being equal, a 200gr bullet will reach the target faster than a 230gr, therefore the 200gr bullet will be subjected to less "airtime" and thus less gravitational pull than the 230gr, therefore the 200gr bullets would be the ones striking high, not the 230gr.

[raynor]

All other things being equal, a 200gr bullet will reach the target faster than a 230gr, therefore the 200gr bullet will be subjected to less "airtime" and thus less gravitational pull than the 230gr, therefore the 200gr bullets would be the ones striking high, not the 230gr.

At a farther distance that may be the case, I only shoot a max of 50 feet.

I have 2 XD-45 ACP's and both shoot the 200 SWC's lower than 230 RN.

The heavier bullet makes for longer time in the barrel. Add to that the extra recoil and by all rights the heavier bullet should hit higher.

[Haizum]

...the heavier bullet typically generates less energy, therefore less peak recoil. From a bench the lighter bullet should hit higher regardless of the target's distance.

I can see how the slower 230 gr would be affected by the slower pushing recoil that the shooter experiences.

[Rattlehead]

Originally Posted by gldP01

Did you try shooting with a bench rest? Also, have one of your buddies sneak a snap cap into the magazine (without telling you which round number it is) and run the magazine through your XD. If you are anticipating the recoil you will notice yourself almost throwing the gun forward when you pull the trigger on the snap cap. That can often cause you to shoot low.

I'm not saying that it's you, just make sure you eliminate yourself as a variable.

Hey, that's a good idea w/ the snap cap.

[jlt]

I recently got an XD 45ACP and took it out and shot 150+ rounds. Being a pistol expert in the Marine Corps I knew that something was wrong either the ammo i was shooting or im just a little rusty. What type of ammo do yu guys recomend?

[Catbird]

Originally Posted by Haizum

All other things being equal, a 200gr bullet will reach the target faster than a 230gr, therefore the 200gr bullet will be subjected to less "airtime" and thus less gravitational pull than the 230gr, therefore the 200gr bullets would be the ones striking high, not the 230gr.

That's a logical conclusion that many people come to, but nevertheless, they/you are mistaken.

If you study "Newton's Third Law of Motion", you'll discover that heavier bullets will impact higher than lighter bullets because of the increased muzzle rise before the bullet exits the barrel.

I certainly cannot control the amount and type of gunpowder utilized in factory ammunition and how that may affect POA/POI, but as you say"All other things being equal".

As a reloader for over 30 years who can control amount and type of powder, I can tell you definitely that lighter bullets impact lower than heavier bullets.

[Ed Ely]

I think that three of you guys were 'milking' the
firearm and the other gent was not.

Please try the 'both thumbs' straight forward
technique the next time you go for a range session.

I predict that you will see a BIG difference and your
round count will be much higher up on the target.

Ed

[bodu]

All other things being equal, a 200gr bullet will reach the target faster than a 230gr, therefore the 200gr bullet will be subjected to less "airtime" and thus less gravitational pull than the 230gr, therefore the 200gr bullets would be the ones striking high, not the 230gr.

If you were to put a .357 SIG barrel in one of your .40 cal USP's, you will find that the .357 will impact lower than the .40 due to higher velocities generated by lighter projectiles. It seems counter-intuative, but shorter time in the barrel means the trajectory is altered less by recoil and the barrel disengaging the slide.