Problems with my Vortex PST

[Lakeman62]

Hi guy's - I'm looking for some ideas here, I mounted my Vortex Viper PST 2.5 X 10 X 32 scope on a SCAR - 17. I don't typically have issues when trying to sight in a new optic but this thing has me scratching my head. The mount I used was a Vortex Precision Cantilever model CM-403. I did a proper ring alignment and torqued the rings to the proper settings as suggested by Vortex. My problem is I had to run the scope to the top of it's capable adjustment for 200 yards and had nothing left for further adjustment when stretching out beyond 200 yards. I was hoping to be in the middle of my available but it ended up being out of all up adjustment to get in the circle at 200 yards. I was also careful not to put too much pressure on the up adjustment but now the clicks for MOA adjustment are gone. needless to say I have pulled the scope to send back to Vortex as I suspect the unit has issues. Has anyone else ran into the same challenge with not having enough up or down adjustment in their scope? Thanks

Steve

 

[42769vette]

Believe it or not most times folks run into this, it is not the scope, it is the rail on the rifle. Did you lap the rings?

The good new for you is, if it is the rail, it is an easy fix with the proper mount.

 

[Lakeman62]

Believe it or not most times folks run into this, it is not the scope, it is the rail on the rifle. Did you lap the rings?

The good new for you is, if it is the rail, it is an easy fix with the proper mount.

I did lap the rings and this is the mount that was recommended from the Vortex rep? so what mount do you recommend? thanks for your reply.

 

[Bsj425]

Did you buy new? If not check mechanical zero with a mirror ( lots of tutorials out there if you have never done this).


The reason being is the vipers have return to zero turrets so prior owner could have zeroed the reset the turret so it's actually not maxed out at all. If you bought new then it should have came at mechanical zero but wouldn't hurt to check.

 

[42769vette]

I did lap the rings and this is the mount that was recommended from the Vortex rep? so what mount do you recommend? thanks for your reply.

The lapping defintally made this issue worse. The only thing you can do to void the warranty on those rings, is lap them. It says in the instructions DO NOT LAP Basically you took something that was perfect down to the thousanth of an inch, and made it as perfect as your hand. Did you send the mount back with the scope? If you have a Vortex REP, Im sure you can call him/her, and they will make it right.

That mount is the best mount in the Vortex lineup for the SCAR. It is made by Bobro, and on my SCAR 17 I use the SCAR mount.

Bobro Engineering | SCAR 30mm Rings Right Side Levers

This is is more than likley a combination of lapping, and the rail not being on the same axis as the bore, so to fix the issue I would run this mount.

https://www.americandefensemanufacturing.com/view/product/867/

 

[42769vette]

Did you buy new? If not check mechanical zero with a mirror ( lots of tutorials out there if you have never done this).


The reason being is the vipers have return to zero turrets so prior owner could have zeroed the reset the turret so it's actually not maxed out at all. If you bought new then it should have came at mechanical zero but wouldn't hurt to check.

The PST does not have a travel limiting zero stop, so that is not the issue.

 

[Lakeman62]

I removed very little in the lapping process as I saw that it was true - 95% of the anodizing is still on the ring so I can't believe it caused the issue.

 

[Lakeman62]

yes I did purchase everything new.

 

[Lakeman62]

Thanks Alan,

I checked the cap set screws and they were not snug. that took care of the click adj.

 

[42769vette]

Thanks Alan,

I checked the cap set screws and they were not snug. that took care of the click adj.

Good deal. Its always easier to diagnose over the phone.

Next time you need an optic just contact me direct. Its good to know this was NOT A PROBLEM WITH THE SCOPE (capalized in hopes folks see it, and I dont get a ton of emails from people talking about the PST not having enough travel to zero).