Adjustable sights for M&P?

[bobbyd]

Is there any adjustable sight made for or adaptable to my M&P .45?
I really like the gun but it is used almost totally at the range and it would be really nice to have sights I could adjust for different loads.

[Lost Lake]

Different loads?

Technically the only difference between loads and impact will be the amount of drop due to bullet speed (time between muzzle and target).

If you figure that the maximum variation between load speeds is only a few hundred feet per second and that the target distance for a combat handgun is only 25 feet or so, the variation in distance falling between loads is really really minuscule.

A bullet traveling at 900 fps falls about 0.15 inch in 25 feet.
A bullet traveling at 1100 fps falls about 0.10 inch in 25 feet.

At 900 fps at 50 feet it drops .61 inches.
At 1100 fps at 50 feet it drops .40 inches.

So at 25 feet the variation could be a 5 hundredths of an inch and at 50 feet 2 tenths of an inch.

What kind of patterns are you getting? Is it worth putting adjustable sights on a gun to compensate for less than a 1/4" at 50 feet?

[MichiganScott]

Originally Posted by Lost Lake

Different loads?

Technically the only difference between loads and impact will be the amount of drop due to bullet speed (time between muzzle and target).

If you figure that the maximum variation between load speeds is only a few hundred feet per second and that the target distance for a combat handgun is only 25 feet or so, the variation in distance falling between loads is really really minuscule.

A bullet traveling at 900 fps falls about 0.15 inch in 25 feet.
A bullet traveling at 1100 fps falls about 0.10 inch in 25 feet.

At 900 fps at 50 feet it drops .61 inches.
At 1100 fps at 50 feet it drops .40 inches.

So at 25 feet the variation could be a 5 hundredths of an inch and at 50 feet 2 tenths of an inch.

What kind of patterns are you getting? Is it worth putting adjustable sights on a gun to compensate for less than a 1/4" at 50 feet?

Correct up to a point. What you are missing is the barrel dwell time from load to load. This dwell time is the reason lighter, faster bullets hit lower on target. Slower bullets stay in the barrel longer and the muzzle starts to flip up and they hit higher.

Even two identical weights from different manufacturers may not hit the same spot on target because different components will cause different barrel harmonics.

Let's not forget your eyes will not see the same sight picture as mine. I have astigmatism and it causes all my shots to hit a bit left of where someone with normal eye sight will hit.

[1sailor]

There is another advantage to an adjustable rear sight. Using the combat hold (front sight covers target) which is required on the MP's I can average about a 2.5" 10 shot group at 50ft and a little over 3" at 25yrds. Using a 6:00 o'clock hold I can get 10 shot goups all touching (pretty much anyway) at 50ft. Unfortunately they are low. In our little informal group we score points by the ring number the shot is in (shots in the white count as points off). With either an adjustable rear sight or a shorter front sight I would be able to greatly increase my score. Not important in combat but luckily few of us will ever have to test our pistols in combat. Try these guys www.dawsonprecision.com SIGHTS REAR:Smith and Wesson Rear Sights:Smith and Wesson Black Rear Sights Category

[bobbyd]

Originally Posted by Lost Lake

Different loads?

Technically the only difference between loads and impact will be the amount of drop due to bullet speed (time between muzzle and target).

If you figure that the maximum variation between load speeds is only a few hundred feet per second and that the target distance for a combat handgun is only 25 feet or so, the variation in distance falling between loads is really really minuscule.

A bullet traveling at 900 fps falls about 0.15 inch in 25 feet.
A bullet traveling at 1100 fps falls about 0.10 inch in 25 feet.

At 900 fps at 50 feet it drops .61 inches.
At 1100 fps at 50 feet it drops .40 inches.

So at 25 feet the variation could be a 5 hundredths of an inch and at 50 feet 2 tenths of an inch.

What kind of patterns are you getting? Is it worth putting adjustable sights on a gun to compensate for less than a 1/4" at 50 feet?

While perhaps theoretically and technically so, actual experience at the range is that the difference between a 230 gr. hardball load, a 200gr. light bullseye load and a 185 gr. high effort JHP defense load might be a couple of inches in elevation. Some lateral/windage shift also is very common although usually of a lesser magnitude. As pointed out by others, barrel dwell time and relative amounts of recoil/barrel lift are probably the reasons. If it were truly 1/4" or less, I would fully agree with you but, in my experience, that's not the case.

[bobbyd]

Originally Posted by 1sailor

There is another advantage to an adjustable rear sight. Using the combat hold (front sight covers target) which is required on the MP's I can average about a 2.5" 10 shot group at 50ft and a little over 3" at 25yrds. Using a 6:00 o'clock hold I can get 10 shot goups all touching (pretty much anyway) at 50ft. Unfortunately they are low. In our little informal group we score points by the ring number the shot is in (shots in the white count as points off). With either an adjustable rear sight or a shorter front sight I would be able to greatly increase my score. Not important in combat but luckily few of us will ever have to test our pistols in combat. Try these guys www.dawsonprecision.com SIGHTS REAR:Smith and Wesson Rear Sights:Smith and Wesson Black Rear Sights Category

Thanks Sailor...just what I was looking for...already placed my order.
Thanks Again!!!