Mounted my MST-100 on my M40A1 clone today and tried to zero using a laser boresighter at 100 yards before I take it to the range. Laser dot was pegged in the middle of the upper right quadrant and I was out of adjustment on both elevation and windage. Thoughts? What am I missing?
Rifle Scopes Trouble zeroing MST-100
- Thread starter Rainier42
- Start date
I've never used a bore sighter, it's very simple to get a rough zero without one. Find a small, well lit, contrasty object about 100 yards away that you can see clearly looking down the bore, it should be small enough to center in the muzzle opening. Then simply zero your MST-100 on a point about 5 inches below the object. If you can't get a rough zero, then something is wrong with your setup. The rough zero is usually enough to get on paper the first time so you can fine tune your zero in a couple shots.
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Is this a USO? What mount?
When you say you are "out of adjustment", do you mean on the knob? You zero it by setting the knobs where you want them, say 100 yards and zero windage, loosen the set screws and adjust the large hex screws in the axis of the knobs to change the POI. Make sure the set screws are snug after you make your adjustments. Not too tight, though, or you'll put divots in the adjusting screw, and when you go to make small adjustments the set screw will find the old divot, setting the crosshairs back where they were before (Don't ask me how I know). Just snug, not gorilla tight.
And like One-Eyed-Jack said, I would do a true bore sight by sighting through the bore.
BTW, your final adjustments (parallax and zero, IN THAT ORDER) should take place at 300 yards, and AFTER you have focused the reticle.
When you say you are "out of adjustment", do you mean on the knob? You zero it by setting the knobs where you want them, say 100 yards and zero windage, loosen the set screws and adjust the large hex screws in the axis of the knobs to change the POI. Make sure the set screws are snug after you make your adjustments. Not too tight, though, or you'll put divots in the adjusting screw, and when you go to make small adjustments the set screw will find the old divot, setting the crosshairs back where they were before (Don't ask me how I know). Just snug, not gorilla tight.
And like One-Eyed-Jack said, I would do a true bore sight by sighting through the bore.
BTW, your final adjustments (parallax and zero, IN THAT ORDER) should take place at 300 yards, and AFTER you have focused the reticle.
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Thanks guys! I completely missed using the hex screws and was trying to use the knobs to set POI.
Oh, good. I'm glad that's all it was.
Here's a good thread you may want to bookmark, complete with pictures:
http://www.snipershide.com/shooting/snipers-hide-rifle-scopes/33458-using-mst-100-a.html
Here's a good thread you may want to bookmark, complete with pictures:
http://www.snipershide.com/shooting/snipers-hide-rifle-scopes/33458-using-mst-100-a.html
Ugh ... went to zero the scope at 100 yards and the elevation hex pretty much does not budge/make any adjustments to the reticle (set screw is actually missing so that's not the issue). Looks like this scope will be going back to US Optics for repair.
This, and if the set screw was missing the adjustment screw would free spin anyhow.
Guys ... just double checked and that's it! What through me off is that the hex lock-down screws are different sizes between the elevation and windage turrets. Smartass is good!
Whatever you do, DON'T touch the allen head screw above the center adjustment screw on the windage knob. It won't be the end of the world if you do back that screw out by mistake (it's the windage stop); just screw it back in if you make the mistake.
Lol, of course i did. Did retighten. Do I need to adjust anything after loosening?
I will learn this scope!
Did you turn the windage knob much while it was loose? If not, it should be fine just to retighten it.
I've never loosened that screw, so don't know if it seats against a shoulder, or if you tighten it then back it off some so the knob can turn. Does anyone else know about that? Rainier, when you retightened it, did the windage knob still turn?
Retighten that screw and ensure you still have the appropriate amount of clicks left and right. I've never messed with that one, so I can't help you beyond that. What I would say is if you don't have a manual for the optic, at least find yourself a FMFM 1-3B online to assist you in zeroing. It's on Scribd as well as many other resources.
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