Im stumped!

Longshot

Longshot

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Ok so I have an s+b pm2. I had it mounted on my rifle on a 20 moa base. Although it wasn't ideal I was able to get her zeroed at 100 and 200 no problem. About a month ago I took it off and took off the 20moa base. I cleaned underneath (although there wasn't much to clean) and then screwed everything back down and loctighted it all in. When I went to the range again I suddenly did not have enough moa down to get reserved at both 100 and 200. I've taken it off again and cannot see anything that would be causing this. Any ideas? Am I missing something in the adjustment? Help me out here?
 
From a strictly mechanical perspective, when you reassembled everything did you hand tighten everything first before you applied any real torque for you final tightening? If all the parts don't sit flush against each other before tightening the won't mate up properly after torquing
 
Only because I've done it myself... On some receivers it's possible to mount the base backwards... Giving you 20 MOA in the wrong direction... Or 40 MOA difference than correct mounting.
 
Whiskey Gulf said:
From a strictly mechanical perspective, when you reassembled everything did you hand tighten everything first before you applied any real torque for you final tightening? If all the parts don't sit flush against each other before tightening the won't mate up properly after torquing
Click to expand...

Yes I did.
 
Haha thanks I'll keep that in mind!
I'm thinking perhaps when I first put the base on there may have been something under it. Now at 200m I was still about a foot high and out of down adjustment. Were I to fire a shim under the base would I be putting it at the rear or the front of the base? Trying wrap my head around it.
 
There should be no way that 20 moa is too much declination that you cannot zero the rifle at 100 yards. We set up rifles with the same scope and a 45 moa base regularly with the ability to zero at 100 yards. There is something else going on that I am lost with. If you need to shim it would be at the front I beleive.
Regards
Guy
 
Yes if you need to shim it will be at the front , if you do shim I highly recommend that you bed the base to the action.

That being said something defiantly isn't right , I'm ruining a SB on my 338lm with 40moa and and with a 100yd zero still have down travel in the scope . Did you remove the scope from the rings ? It may be possible that they were torqued incorrectly and are torquing on the scope and while the dials move the scope doesn't mechanicaly adjust the proper amount it should.

Sort of a shot in the dark I know but it's something to look at

Did you lap your rings ? If you lapped then mixed up front and rears it would also put some odd stress on the scope
 
If the rings were lapped, might one have been turned around during the re-assembly.
Shimming the front/muzzle end of the base defeats the purpose of the 20moa base.
Correct screws in the breach end of the base so they don't bottom out.
I'm just throwing these out there.
 
tigrr said:
If the rings were lapped, might one have been turned around during the re-assembly.
Shimming the front/muzzle end of the base defeats the purpose of the 20moa base.
Correct screws in the breach end of the base so they don't bottom out.
I'm just throwing these out there.
Click to expand...
Good stuff. I will probably shim it until I can figure out what the heck is going on.
 
First thing I would do is take another scope, center the reticle, mount and shoot at 25 yards

That will tell you where the next step is.
 
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