Need some info. New .40 S&W Performance Center shooting 3 inches low at 7 yards. Shooting reloads: 155 gr LSWC. Tried two loads: 5.4 grs and 6.0 grs of HP38 (same results for both). 5 inch barrel. Federal 100 primers with Federal brass, fairly heavy crimp. OAL 1.129. I thought it was my but my son achieved same results. Fellow shooter had factory loads and they were right on bullseye.
Does the gun not like HP38, 155 gr LSWC, Federal primers, Federal brass, the heavy crimp, or all of the above.
Thanks in advance for any help.

If factory ammo works than its your reloads. It can be any one thing or everything you mentioned.

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First consideration is light bullets shoot low, and heavier bullets shoot higher because of longer barrel dwell time for the barrel to rise.
Therefore, for a fixed sight gun, you can change bullets and change the point of impact.
EXAMPLE: My fixed sight .40 Browning HP shoots to POA with 165gr bullets, and high with 180grain.
My adjustable sight .40 shoots 180gr bullets, because I adjusted its sight to match the heavier bullets.
Bullet weight and shooter technique are the prime suspects in pistols that shoot high or low.
My advice is try 165gr and 180gr bullets, and make sure you are not breaking down on the shot, which also throws low.

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Science plus Art

Thanks, OKFC05. I was shooting from a rest just to make sure it was not me.
Guess a trip to the gunshop is in order.

Buy the same weight bullet as the factory ammo that shot to POA , check the FPS listed and load to match it.
It's surprising the doesn't come with adjustable sights , then it would be simple matter of dialing in your sights to your load.
My fixed sighted model 64 got a red dot sight installed on it so I could adjust the sight to the load.
The S&W site does say it's a fixed rear sight , not much you can do there.
Gary

If the issue is in fact caused by light bullets, then a trip to gunshop won't help unless it's to buy heavier bullets.

There's another possibility. I don't mean to criticize anyone shooting techniques, but some people use different alignment methods to aim their firearm.
Referring to the picture below, compare sight image 2 and sight image 3. With the type of sights found on most M&P handguns I believe the proper way to align your sight picture is sight picture 3 where the center blade actually covers the target area you intend to hit and all three white dots are aligned horizontally. If you are aiming using sight picture 2, then you will more than likely be shooting low all of the time.
To many it seems odd to actually cover the target with the center blade because it does cover part of the target, but for defensive shooting this is common since it allows for faster target acquisition and normally you aren't concerned with pin point accuracy.
Sight picture 2 shows proper sight alignment with sights other than tactical 3 dot sights and it shows the tops of all 3 portions of the sights being aligned horizontally actually at the point of aim. This method doesn't cover the target area, and is used for a more accurate pin point type of aiming.
Again I'm not trying to be critical, but this might be the problem. I would at least check it out before making any modifications to your handgun.

Attached Images

sight alignment.jpg (45.1 KB, 133 views)

Thanks for all the replies. I will try using sight image 3 and if that does not help the problem then I will be going to the gunshop for 180gr bullets.

Buy a box of 155gr ammo and try that first. Shoot it the same way you shot your reloads. And then try the different sight pictures

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While a lighter bullet will shoot lower in the 40 caliber my experience is that the shift in POI between a 180 and 155 grain load will be in the range of 2 inches at 25 yards. Your report of a shift of 3 inches at only 7 yards is way outside of that range. It is also way outside of the normal range of correction with the various sights available for sale. I would conclude that your slide was either machined with the barrel pointing low or that you are indeed "pushing off".

I'll add one note to rbuzz's great post. You can spray sight black on your sights to help you with accuracy testing to avoid the distraction of dots and the tops of the sights, then wipe off the sight black and decide how you're going to use the dot sights in aiming for the rest of your shooting.

That said, I'd expect the sights to be calibrated to a 165 or 180 grain bullet from the factory, as opposed to a light-for-caliber bullet.

Chronograph your handloads and the factory ammo. I bet your reloads are running a higher velocity.

Lighter bullets shoot lower due to less barrel rise. Shooting the lighter bullet at a higher velocity means it leaves the barrel sooner so less rise still, and a lower impact.

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