My Sigma shoots at least 12 inches left at 10 yards, where other pistols shoot true.

How hard is it to move the rear sight. How did you do it, or how does the gunsmith do it?

its real easy you just gotta use a punch. theres a sight adjustment tool but its like $100. you can move your sight but i'd recommend working on your grip and your trigger pull. its more likely your shooting incorrectly than you need to adjust your sights. watch some youtube videos and get some snap caps. the sigmas long gritty pull tents to make you shoot way off but with lots of practice it will make you a better shooter overall.

12" @ 10 yards is a LOT!! Maybe something is seriously wrong with the gun, but it may be just your grip. Some people shoot better with one type or another gun, and when shoot well with one, then buy another, they don't believe that is the reason they are now having trouble.

Maybe this will help you some.

Those charts are helpful in certain circumstances but they are utterly meaningless unless one proves that the sights are properly regulated--and a proper sight picture is being used--in the first place.

I call my training Sigmas the Great Revealers.
I have carefully selected the ammo type and adjusted the sights for the usual top of front sight POI.
When the students shoot them, the REVEAL whether the shooter knows proper trigger control, or has been relying on heavy guns and light triggers to mask poor technique.

Suggest you have a qualified instructor/pro shooter shoot your Sigma and also watch you shoot. If needed, the rear sight can be drifted easily; I use a nylon punch.

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Science plus Art

I like to use a brass or plastic (Delrin) punch and a small hammer. Before I start I make sure that anything holding the sight in place has been loosened , then I like to pull the slide off the gun & place it in rubber vise jaws, or in a pinch a couple pieces of leather. Place the punch against the side of the rear sight, as low on the frame as possible & give it a tap- You need a good eye to tell if it has moved & how far. Of course out on the range table you can't always find every tool you might hope for, unless you bring your own. Most people do best to let someone else work on their guns, a slip of anything can cost more than the most expensive sight mover tool to repair. Said sight mover can be found at World's Largest Supplier of Firearm Accessories, Gun Parts and Gunsmithing Tools - BROWNELLS
If you type sight mover into the search box they all come up.

First time I shot my Sigma I was shooting about 12 inches low at 10 yards. I thought, this sucks. Your most likely jerking the trigger.

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The kool-aid Sigma drinker

Assuming it's the gun and not the shooter:

I experimented with mine as follows:

I got a brass screw from Lowes and filed a smooth taper towards the end of the threads. Then of course, smoothed out the end of the screw so that it felt smooth and there were no threads left near the tip. Brass is soft and it won't hurt the plastic sight on the mighty sigma if you tap it gently. Tap the head of the screw gently with a hammer and the sight easily moves. It is a simple operation.

If the gun is that far off, I'd call Smith.

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SD9VE, American perfection!

Thanks, guys. I read the manual (last resort). It said one can move the rear sight. I found a brass nut and a small hammer and moved it too far, then back enough - I think. I'll learn at the range.

Your remarks about holding are very good, too. I have light hands and something can move easily, but my other guns shoot pretty well with the same hold. My friend has strong steady hands and shoots other guns very well. It was he who said this one is off and showed how far off he had to aim to get the bullets to hit near the bulls-eye.