M&P40 Hold and POI with Dawson Sights?

[rdtompki]

I recently put on Dawson sights: .245" fixed rear and .180" FO front as recommended by Dawson. The gun appears to shoot 2-3" low at several yards. I'm going to the range on Friday to nail this down using my stock sight 40 and the Dawson-equipped 40, but looking at some old threads there is some discussion of the hold for which the stock sights are configured. I do experience this low shooting both freehand and from a rest.

Anyone out there using my Dawson sight configuration on either a 9mm or .40 cal care to comment on your POI and hold?

I'll also add that I spoke with Michael at DP and they will send me gratis the correct height front sight if the 40 doesn't zero at my reference range. They use 25 yards. I hope my shooting, even from a rest, is up to the task of achieving a small enough group to determine a representative POI.

 

[Llando88]

Don't have Dawson sights or a 40, but I'd be interested in the numbers (heights) of the sights (front and rear) of the original stock sights you replaced to put on the Dawson sights.

My FS9 shoots 2.6" high at 7 yards, and I am pretty sure it's due to the incorrect sight heights on my Trijicon HD night sights.

I'm curious to do the trigonometry, to see if there are any comparisons to be made in your case, shooting a couple inches too low.

Good luck with the Dawsons, I just ordered a 10 8 FO 0.160" tall front sight and am pairing it with my stock rear (blacked out). I'll be selling the Trijicons after they come off.

 

[hardluk1]

Stock sight height is set for 25 yards with most pistols and that will cause bullet impact to be several inches low at your "several yards" . 5 to 7 I would guess your shooting at. Shorter front sight would be needed if that's all your going to shoot but I would say to sandbag your pistol at longer distances 15, 20 , and 25 yards using a quality HP ammo to see where it prints. Then make a choice for the range and ammo you use.

OR

Replace your rear sight for one of there adjustable rear sights so you can set it how you want for the distance and ammo used !!!

https://www.dawsonprecision.com/Cat...son+Smith+and+Wesson+MP+Adjustable+Rear+Sight

 

[rdtompki]

Stock sight height is set for 25 yards with most pistols and that will cause bullet impact to be several inches low at your "several yards" . 5 to 7 I would guess your shooting at. ......

I'm not sure this makes sense. If the POI is several inches low at, let's say, 7 yards how can the POI be dead on at 25 yards? The bullet should continue to drop as range increases. My gun is shooting low at these shorter distances and definitely low(er) at a greater distance. I'll post my range results in a few days.

 

[hardluk1]

`Just shoot your pistol from a rest and you'll see. Not going to try to explain it .

 

[rdtompki]

`Just shoot your pistol from a rest and you'll see. Not going to try to explain it .

I think it's worth and explanation, setting aside my original post which may well be related to sight picture, trigger pull, etc.

Imagine setting a target at 25 yards with a handgun on a bench rest. Assume POA = POI; the gun is proper sighted for 25 yards. Now without changing the alignment introduce a target at 7 yards and position the target so the sights are aligned on the bullseye. I might be getting senile, but there is no way a bullet properly sighted in for the 25 yard target will strike the 7 yard target "several inches" low.

 

[Llando88]

For reference, my thread on the Trijicon HD sights hitting high is here:

http://smith-wessonforum.com/smith-...ht-sights-shoot-bit-high-vs-stock-sights.html

That's where the math is for the numbers I used.

My stock sights are 0.170" rear and 0.160" front (height above slide).

 

[rdtompki]

For reference, my thread on the Trijicon HD sights hitting high is here:

http://smith-wessonforum.com/smith-...ht-sights-shoot-bit-high-vs-stock-sights.html

That's where the math is for the numbers I used.

My stock sights are 0.170" rear and 0.160" front (height above slide).

I'm surprised that the night sights would differ so greatly from stock. We're only talking about 1" of ballistic drop over 25 yards and .010" variation in sight height for a 6.5" sight radius is slightly more than an inch at 25 yards.

I measured the Dawson sights and the front/rear difference in on the order of .010" and after a recent range trip I've determined that all I have to do is look in a mirror to find the culprit.

 

[SoCalDep]

Stock sight height is set for 25 yards with most pistols and that will cause bullet impact to be several inches low at your "several yards" . 5 to 7 I would guess your shooting at. Shorter front sight would be needed if that's all your going to shoot but I would say to sandbag your pistol at longer distances 15, 20 , and 25 yards using a quality HP ammo to see where it prints. Then make a choice for the range and ammo you use.

OR

Replace your rear sight for one of there adjustable rear sights so you can set it how you want for the distance and ammo used !!!

https://www.dawsonprecision.com/Cat...son+Smith+and+Wesson+MP+Adjustable+Rear+Sight

That is completely wrong unless you're shooting an AR-type pistol with massive sight-over-bore. Since we're talking about M&Ps, any shift in point of aim/point of impact in a properly sighted and zeroed M&P will be negligible between 0 and 25 yards.

 

[rdtompki]

That is completely wrong unless you're shooting an AR-type pistol with massive sight-over-bore. Since we're talking about M&Ps, any shift in point of aim/point of impact in a properly sighted and zeroed M&P will be negligible between 0 and 25 yards.

Couldn't agree more.

 

[Llando88]

I'm surprised that the night sights would differ so greatly from stock. We're only talking about 1" of ballistic drop over 25 yards and .010" variation in sight height for a 6.5" sight radius is slightly more than an inch at 25 yards.

I measured the Dawson sights and the front/rear difference in on the order of .010" and after a recent range trip I've determined that all I have to do is look in a mirror to find the culprit.

You know, I think I have that same mirror.


But seriously, yes, the 0.010" delta front to rear is what I am going back to.

I was astonished frankly that the math in my case exactly matched the predicted amount by which I shoot high with the installed Trijicon HDs. The rear sight height is much bigger than it should be, IMHO.