[watchnut]

I shot my 1911 Commander this evening from 50' for the first time. I was practicing for shooting Combat at my local range. (From 20' I was okay). All my shots were to the left of center. I had the range officer try and he had the same problem. How does one adjust the rear sight to correct the shots? My gun is a Mark IV, series 80 Commander. The rear sight is dovetailed in. Can I tap with a brass hammer? Which way do I move to correct the shots being to the left of center?

Thanks!

 

[JohnnyP]

Rear sight moves in the direction you want your group to move, so it moves to the right. I would try to find a gunsmith that has a sight pusher. A brass hammer will still bend the sight, and hard to control how much you move the sight.

 

[watchnut]

thanks for the guidance!! I'll try the "brass tap" method easily first to see if I have movement in the sight. If not GS here I come.

 

[brianfede]

I used a nylon hammer. Took a bit of time to get it right, but it worked just fine.

 

[JohnnyP]

Better get a brass punch if you want to do it yourself. You will either bend up the thin part of the sight or the dovetail in the slide. You seldom hit where you want to by trying to drift the sight with a hammer. Also a vise is a great help holding the slide.

 

[dickttx]

I was able to move the rear sight of a 1970 Commander using a brass hammer and a brass punch. Not real easily, but it did go.

 

[watchnut]

Thanks for all the comments!! Not sure how much to move it as the shots are hitting 6"-12" to the left of center. It is a little difficult to take all the tools, including a vise to the range. I'll try moving a little bit prior to my next trip to the range.

 

[dickttx]

That is what I did. I just moved it a little before I went, tried it out, moved it again before next time, etc.

 

[dogface6]

You can make an 'index mark' with a mechanical pencil on both the slide and sight - it'll give you a good idea of how much you've moved the rear sight as you tap it.

You don't mar either surface, and the graphite mark rubs off.

 

[JohnnyP]

12" at 50 feet is a bunch. Averaging it out to 9" would require the rear sight be moved about 0.085 to the right. There should already be an index mark on the sight, and you can measure over from this to see how much to move it. 0.085 is going to be between 5/64 and 3/32 inches.

Sounds like something else other than incorrect sight adjustment. Before I moved the rear sight that much I would put a sticky on the rear sight and draw a notch that much farther to the right. Your elevation will be off, but you should be able to see if the correction moves your group.

 

[watchnut]

You can make an 'index mark' with a mechanical pencil on both the slide and sight - it'll give you a good idea of how much you've moved the rear sight as you tap it.

You don't mar either surface, and the graphite mark rubs off.

Great idea!!

 

[watchnut]

12" at 50 feet is a bunch. Averaging it out to 9" would require the rear sight be moved about 0.085 to the right. There should already be an index mark on the sight, and you can measure over from this to see how much to move it. 0.085 is going to be between 5/64 and 3/32 inches.

Sounds like something else other than incorrect sight adjustment. Before I moved the rear sight that much I would put a sticky on the rear sight and draw a notch that much farther to the right. Your elevation will be off, but you should be able to see if the correction moves your group.

How did you arrive at the amount to move the sight? Also I do not see any index mark on the sight or slide. Should it be visible? Good idea about the sticky. Going to work on it before I go to the range next week.

 

[JohnnyP]

Maybe yours doesn't have one, but I don't believe I ever saw a fixed sight Colt 1911 style pistol without one.

Not much but it is an index mark.

 

[watchnut]

Maybe yours doesn't have one, but I don't believe I ever saw a fixed sight Colt 1911 style pistol without one.

Not much but it is an index mark.

[/QUO

Thanks for the picture. Just looked again and no index mark. The gun is a Mark IV, series 80, Commander made in 1991.

 

[JohnnyP]

Probably costs too much to put an index mark on them now.

Forgot to tell you how I arrived at the figure your sight needed moving. Convert everything to inches. 9 (distance off) X 5.75 (sight radius) / 600 (inches to target) = 0.086. Does that not agree with what you figured?

 

[watchnut]

Probably costs too much to put an index mark on them now.

Forgot to tell you how I arrived at the figure your sight needed moving. Convert everything to inches. 9 (distance off) X 5.75 (sight radius) / 600 (inches to target) = 0.086. Does that not agree with what you figured?

Forgot most of my math skills but that sounds right. Thanks!!!

 

[halfmoonclip]

I realize that the range officer had similar results, but it still may be pilot error. Consider having someone else load some dummy rounds at random thru' your magazine and see what happens when you try to shoot the snapcap. If you're guilty of trigger mashing or other sins, you'll see it immediately when there's not recoil to hide it.

Beyond that, try to adjust the sights at the range yourself with your hammer and brass drift; it allows you to experiment as you go.
Good luck and keep us posted.
Moon

 

[watchnut]

Thanks for all the comments!! Will try the snap cap routine first. Then I need to get a brass punch for adjustment. Will make the initial adjustment on the bench and then take to the range within the next couple of weeks to try it out.

Will keep all advisors informed as to my progress.

 

[jrprich]

Adjusting fixed sights


Rear sight:


Windage (Left/Right) Adjustment
Change windage by moving the rear sight either to the left or right in its dovetail.
When you do this, follow the rear sight rule:
Move the rear sight in the direction you want the group to go.
Moving the rear sight 0.020” in the dovetail changes the point of impact by approximately 3” at 25 yards.

But it could easily be caused by how you place your finger on the trigger.

 

[watchnut]

Thanks for the guide to possible problems.