Sight question, 10-8 rear-what front?

[Dave Berryhill]

So Dave, if I want to replace, I just order a front sight that is .325?
So the simple rule is: Front sight height should equal rear sight height correct? Pretty basic but you never freaking know the rules till you know the rules.

Sorry but no gold star for you. The simple rule is to keep the front and rear sight heights the same if you don't want to change the POI.

Corollary #1 is to keep the difference in heights the same when measured from the same reference plane if you don't want to change the POI. One example would be the .375 tall 10-8 rear sight example I used earlier. Since you are not altering the dovetails, if you raise the rear sight by .050 then you would need to raise the front by the same amount if you don't want to change the POI.

As another example, lets say you have a Colt or Springfield Armory pistol with standard GI sights. You can measure the height of the front and rear sights from the same plane (this can be the top of the slide, the bottom of the slide, the axis of the bore, etc). We need to use a reference plane that will not change when we machine the slide.

Lets say the difference between those heights is .060. In other words, the rear sight is .060 taller than the front sight when measured from the same plane. If we mill the slide for front and rear dovetail sights, the difference between the new front and rear sight heights also needs to be .060 when measured from the same plane as before.

Now you can mill a Novak rear sight cut, install the rear sight and measure it from our reference plane. Since the front sight needs to be .060 shorter than the rear sight, we can calculate the height of the front sight needed.

In reality, there may be a slight change in POI after installing the new sights no matter how carefully you measure. It's usually not significant and won't make a difference for a self defense pistol. Shooting an inch high or low at 25 yards for a center mass shot really doesn't matter but this is why some pistolsmiths will install a blank front sight, leave is slightly tall, test fire the pistol, calculate the amount of correction needed and then shorten the front sight by the required amount.

[Pappabear]

Dave, thank you.

[Doru]

Anyone try putting an XS standard dot on the front with a 10-8 at the rear? I'm considering it.

Guessing it makes a difference, I'm considering using it on a Springfield Operator.

Anyone try this combo out? Thoughts?

Thanks,

Drew

[ColdDeadHands]

Our member Chayse has that setup on his Operator. Post 2046 in the 1911 Handgun Picture thread. Looks like a nice setup, I wouldn't mind trying that myself.

[Dave Berryhill]

Anyone try putting an XS standard dot on the front with a 10-8 at the rear? I'm considering it.

Guessing it makes a difference, I'm considering using it on a Springfield Operator.

Anyone try this combo out? Thoughts?

Thanks,

Drew

I've done a couple. Some guys really like them and I think using the 10-8 rear sight is a big improvement over the express rear sight that XS uses - it's just as fast but more accurate.

I'd like it a lot better if the XS front sight was a square post with the big dot on it instead of having rounded corners. When I want to shoot accurately, I have a hard time aligning the top of the front sight with the top of the rear sight because of this.

[Doru]

Dave,

I've heard the same thing about people wishing the front sight was squared. I've shot w/ Big Dots on my Glocks for a few years. I'm hoping I can split the difference.

Glad to know others are running that setup.

Drew