Shooting low

[FUNDAMENTALS]

There is one thing that I have observed with new shooters and their
pistols when sighting in. "Line of Sight", and Target Location. Ensure
the target is at the same "Height" in relation to your Line of Sight. You
should not be aiming with your sights at a target which is "Lower" or
Higher, especially if you are shooting from the "Standing Point Shoulder
Position". When Shooting the pistol from a rest, again ensure the target
is "Level" with your Line of Sight so that the "Point of Airm" is level with
your Master Eye, The Sight Picture and the Target.
Practice regime of the "Magnificent Seven", as I call them:
1. Stance
2. Grip
3. Sight Alignment
4. Sight Picture
5. Breath Control
6. Trigger Control(Squeeze/Press)
7. Follow Through.
Your description indicates to me better management of 2thru 6.
Just out of curiosity, as your attempt to "Squeeze" the trigger are
you unknowingly adding additional pressure to the entire grip, causing
the Sight Picture to wobble even more?
HINT: Take your pistol in your strong hand, with your trigger finger
along the frame. Aim it at the target and squeeze the grip until it
appears as if starts to vibrate, then back off the pressure on the grip
until the vibrating stops. That is your grip. The only pressure that is
then applied is the "Trigger Finger" on the trigger itself in the proper
position and "Squeeze/Press". Hope my info helps a little.

[Yoder]

Buy this book: Practical Shooting Beyond Fundamentals by Brian Enos.

Here's the link:

http://www.brianenos.com/pages/reviews.html#be

This book has helped improve my shooting 1000%. Some of the book will immediately make sense and some of it will come to you as you shoot more. It will definitely improve your shooting.

[synergy]

It's just flinching.

You mentioned you are trying to keep them on a paper plate at 10 yards. If you are executing the fundamentals properly, Glocks will group like this.



That's 4 shots from a G26, at 7y...left hand only (RH shooter). I pulled the one....


There is likely nothing wrong with the Sig, you just don't have the trigger control you need to shoot it well, and you're flinching.

Some of the links/ books mentioned have all of the info you need to begin to correct this. Getting some training from a competent shooter, or knowledgeable coach would help greatly, too.