Alright. I give up.

Couple range trips and for some reason. I can not
Get this rifle dialed in with the Factory drum sight and front hood.

Using the open sights, it seems with a maxed out height, it continues to shoot 5 inches low (although with great groups)

Yes. I can throw a red dot on it (suggestions?) but god I wanna figure this out.

The rifle is stock. With the exception of a Sandman L QD flash suppressor. Which is not being used on it for this exercise.

I do appreciate the help.

What range are you shooting from? Are you using the peeps or the notch? If peep: which peep?

The 550/551 user manual calls for partially covering the target with the front blade, for POA/POI; so don't do a six o'clock hold. Also, If you're trying to get a rough zero at a very short distance, you may run out of adjustment; a POI will be low at CQB distances, with a normal zero.

You shouldn't run out of adjustment either way though, I don't think. I'll have to examine my guns, to see if any of them are near the extreme end of the adjustment range. There are different height front sights as well; or you could carefully file yours. Are you using the front night sight blade? It sits slightly higher, if I recall correctly, which would cause you problems.

What say PGT?

What rear sight do you have?
The weldment or the rail mount?
How tall is your front sight?

I'm asking because I think there may be a miss matched set.
Sig 55x have two different rear sights and different front sight heights.

.

The difference in height of the two fronts I have is .030"; probably not enough to account for what the OP is seeing(depending on range). Maybe a worst-case mismatch of both front and rear could do it. It seems the likeliest cause is the use of the front night sight, but that probably would have been realized at the range. Of the guns available to me, two of them are near the top of their elevation adjustment range, but they represent the minority.

There are three hooded front sight heights; N+, N and N-. N+ is normally what comes on the Swiss 553. That said, the sight blade itself can be changed out.

Got pics to share? The sight should be marked on the front edge, above the regulator.

quote:

the sight blade itself can be changed out.

On a hooded sight?

yes, there's a fixed post machined into the base up front and a flip down in the rear (with tritium and fingernail ledge) on a hooded sight. it rotates forward on a silver pivot pin with a spring and detend underneath.

Also...the flip-down blades have numbers on them for height so you can change out three heights of hoods/fixed blades (N+, N or N-) or the flip-down blade.





exploded diagram

I think perhaps that your rear drum adjustment isn't working properly. They can be stiff and stick. If you're sure the front is an N+, check the movement of the diopter assembly in the back. It might not be moving when you adjust it.

I've had one seize in place and the threaded post snapped (luckily I had spares).

Take some pics of what the markings are on your front sight assembly please.

I aware of the fact that a night sight is removable; I am assuming the OP is zeroing with his fixed blade. Until he gives us more info, we're not really able to help him.

Per usual. The responses are great.

I’m going to get some responses up today.

This is a JDI gun with welded rear drum.

Since it’s a short barrel. I’m just looking to do CQB distances. Max of 100 yards.

The issue is at approx 10 yards. 4/5 inches below center hold. Again, great groups. Just low and no more room to crank it to the right (per Manual)

You're referring to turning the elevation adjustment clockwise, when you say "cranking it to the right"?

Ic Switzerland short distance zeroing is done at 30meters with the diopter drum set to position 2.

quote:

Originally posted by KSGM:
You're referring to turning the elevation adjustment clockwise, when you say "cranking it to the right"?

There is a screw that you turn to the right. Book says if you are shooting low to turn it right.

Gotcha. That is correct.

Definitely check the front sight marking and also that the drum is moving up or down when adjusted for the rear.

Any more insight on this, leonidas? Did you confirm that you weren't using the front night sight?

I have not been able to get back out to the range but have been thinking about it.

I was In fact using the night sight blade. Intuitively, read dots and then the front one made sense to me.

I see, looking at it how that could make a difference… I am going back out this weekend with a spotter and will get this right.

Going to make sure my drum is moving on corrections as well.

Will report back.

I want to thank you all for input.

At the range today. I flipped down the white dot front sight to the black smaller one. On target, no problem.

I still don’t understand what the other sight is for?

Also, she is chewing up brass. Love shooting it, but crushing the front of the case.

Put a Sandman L on it, was fantastic.

quote:

Originally posted by leonidas211:
I want to thank you all for input.

At the range today. I flipped down the white dot front sight to the black smaller one. On target, no problem.

I still don’t understand what the other sight is for?

Also, she is chewing up brass. Love shooting it, but crushing the front of the case.

Put a Sandman L on it, was fantastic.

Yeah, they damage brass, assuming you can find it after it gets chucked a country mile!

You need a four position regulator and 0.9 suppressed setting