Rifle Scopes 20moa base question

[elwarpo]

I have a RPR (comes with a 20moa base) and I zeroed (100 yards, 6.5 CM) my Vortex viper PST gen 1. I am using Vortex matched 1.45" rings.

The scope has 19 mil of elevation, zeroed without a 20moa base I would expect around 9.5 mil up and 9.5 mil down. With a 20 moa base I would expect 15 mil up and 4 mil down movement. I get 8.3 mil up and 10.5 mil down. I tried this with 2 different PST scopes (the first was returned to Vortex and they replaced it.

I measured the scope rings and they are within 1 or 2 thousandths of each other and that is probably me and not them. I measured the rail and it is about .04" lower in the front.

What am I missing?

 

[EXTREMEPREJUDICE]

A quick search finds the most common base sold for that rifle to be 40 MOA, which obviously says something about the optic/base requirements for that design. If yours has a 20 MOA base then just offhand i would say you need 20 MOA more to accomplish your desired elevation/erector travel goal.

 

[elwarpo]

Thanks Extremeprejudice, I have googled the best base for a RPR, and while some companies make 0, 30 and 40 moa bases, I have not found anywhere that the stock 20moa base is not good enough. I tried searching here and the search function is difficult to use. When I put in ruger precision rifle 20 moa base, any thread with any of those words comes up. I spent over an hour yesterday searching and came up with nothing. That is why I posted here.

I am just curious if I have a RPR with a bad base or do I need a 40moa base?

 

[fastfwd]

I tried searching here and the search function is difficult to use.

You may have better luck searching the site using Google. For example, go to google.com and enter this in the search box:

site:snipershide.com "ruger precision rifle" "20 moa"

I am just curious if I have a RPR with a bad base

If you're confident in your measurement of a 0.04" drop from rear to front of your rail, and if your rail is around 7" long, then it's angled at 20 MOA.

 

[EXTREMEPREJUDICE]

I am just curious if I have a RPR with a bad base or do I need a 40moa base?

Just based on your description with your rings and optic to maximize your elevation you most likely need a 40 MOA base. That's not uncommon, and depending on the use for the rifle you might want to go with a more angled base or you could put rings with build in cant on top of your 20 MOA base. On the other hand, I know that just in general you would prefer more upward travel but based on your intended use 8.3 mils might be plenty of adjustment. I would doubt that there is a problem with your 20 MOA base (meaning defective.)

 

[elwarpo]

Thanks guys, 40moa base ordered.