Adjustment / MOA question



Author Topic: Adjustment / MOA question  (Read 209 times))

Offline JimR

  • Plinker
  • **
  • Posts: 184
  • yes
  • Real Name: jim
Adjustment / MOA question
« on: January 23, 2019, 11:14:25 AM »
If scope "A" has 50 MOA adjustment and scope "B" has 100 MOA adjustment, mounted with the same rings, on the same gun, if "A" maxes out before zero would "B" still have adjustment left ?

Offline Gear_Junkie

  • Expert
  • *****
  • Posts: 1819
  • Real Name: Zack
Re: Adjustment / MOA question
« Reply #1 on: January 23, 2019, 11:53:32 AM »
If scope "A" has 50 MOA adjustment and scope "B" has 100 MOA adjustment, mounted with the same rings, on the same gun, if "A" maxes out before zero would "B" still have adjustment left ?

Theoretically, yes, you would have an additional +/-25MOA adjustment.  However, this assumes that both scope internals have the exact same alignment/adjustment (unlikely).  The only real way to find out how much additional adjustment available would be to test each scope.
  • Nevada City, CA
.177 Daystate Regal XL & Hawke Airmax 30 SF 6-24x50
.177 Air Arms TX200 HC & Hawke Airmax 30 SF 6-24x50
.177 HW50S & Compact UTG 3-12x44

Offline JimR

  • Plinker
  • **
  • Posts: 184
  • yes
  • Real Name: jim
Re: Adjustment / MOA question
« Reply #2 on: January 23, 2019, 01:35:46 PM »
Thanks Zack.

Offline nervoustrigger

  • GTA Senior Contributor
  • ******
  • Posts: 6046
  • The Grin Reaper
    • My youtube channel
  • Real Name: Jason
Re: Adjustment / MOA question
« Reply #3 on: January 23, 2019, 01:49:31 PM »
Agreed, and generally the advantage goes to the scope with the larger tube (e.g. 30mm rather than 1 inch).  More room for the erector tube to be moved up/down and left/right.

In some cases there just isn’t enough vertical adjustment, such as shooting at long range (>100yds) or if the gun happens to have a barrel and scope rail that diverge.  In those cases you either need an angled scope mount (“dropper mount”), adjustable mounts, shim between the rings and scope tube, or slightly arc the barrel.

Offline JimR

  • Plinker
  • **
  • Posts: 184
  • yes
  • Real Name: jim
Re: Adjustment / MOA question
« Reply #4 on: January 23, 2019, 02:18:33 PM »
Here's the scenario : Had a hawke 4-12x50 with 100 MOA adj Vantage on an R9. Worked great. Took that scope and high rings and put them on a TX200 also works great. Had a hawke Varmint 6-24X44 with 50 MOA adj that I mounted with high rings on the R9 and it runs out of adjustment down before it gets zeroed. I have a Hawke 3-9X50 Vantage with 90 MOA that I can try on the R9. Just wondered if "theoretically" it should work. Don't think I have barrel droop as it was fine with the other scope.

Offline Sfttailrdr46

  • Of all the things I have lost I miss my mind the most
  • GTA Moderator
  • GTA Senior Contributor
  • *****
  • Posts: 13681
  • Think first then hit send
  • Real Name: Don
Re: Adjustment / MOA question
« Reply #5 on: January 23, 2019, 02:27:09 PM »
The only easy way to determine barrel droop is to mechanically center the scope and then see how much elevation is left after the rifle is zeroed. If the erector tube is almost at the stops then you have a drooping barrel or it was bent. Either way the scope will be stressed and in all likelihood may not hold up well even if it is AG rated   
  • Long Island N.Y.
AA S510 Xtra Fac .177 RH Walnut
Beeman RX-2 .20 cal
BSA R-10 MK II SE .22 FS
Rainstorm II .22 AWESOME Rifle
Air Speed .25 Smile Machine
Gamo Whisper Fusion .177
Gamo Swarm Maxxim .22
Marauder GenII .30  Boyd's TH 100+ fpe
RWS D460  .177  
PP700 SA ,22 PCP pistol W/Rocker1 LDC & Red Dot
CP2 .22 Pistol/Carbine
SPA Varmint .177
Freedom 8 & Guppy CF Tank & 45 min SCBA
 https://www.zeemaps.com/map?

Offline Pellgunfun

  • Sharp Shooter
  • ****
  • Posts: 799
  • If text is personal, why would you ask?
  • Real Name: Fun... Pellgun Fun
Re: Adjustment / MOA question
« Reply #6 on: January 23, 2019, 02:50:56 PM »
No matter if I'm shooting PB's or air guns, I always start with the Scope Mechanically/Optically zeroed, and then get in as close to with whatever means necessary BEFORE i start zeroing the rifle.  On my PCP guns, so far I've been very lucky with just turning the barrel a 1/4 turn.  Powder Burners are a bit harder as you can imagine.  :)  But that's just me, to each his own I suppose, but for me that works best.

I had an R9 and never did I experience any significant barrel droop.  Take that R9 and hold it upside down and whack the barrel on a fence post.  :)
Mrod-Air P-12, in .22 cal
BAM XS B-50, in .22 cal

Offline JimR

  • Plinker
  • **
  • Posts: 184
  • yes
  • Real Name: jim
Re: Adjustment / MOA question
« Reply #7 on: January 23, 2019, 03:00:36 PM »
I don't think there is an issue with the R9. It was shooting fine..........I simply robbed the scope and rings to put on a TX200.....I'll research mechanically resetting scope ( unless someone has a simple direction they wish to share ).

Offline Sfttailrdr46

  • Of all the things I have lost I miss my mind the most
  • GTA Moderator
  • GTA Senior Contributor
  • *****
  • Posts: 13681
  • Think first then hit send
  • Real Name: Don
Re: Adjustment / MOA question
« Reply #8 on: January 23, 2019, 04:37:23 PM »
adjust either all the way up or down then count how many turns to the opposite stop point then go half way back then do the same for windage
  • Long Island N.Y.
AA S510 Xtra Fac .177 RH Walnut
Beeman RX-2 .20 cal
BSA R-10 MK II SE .22 FS
Rainstorm II .22 AWESOME Rifle
Air Speed .25 Smile Machine
Gamo Whisper Fusion .177
Gamo Swarm Maxxim .22
Marauder GenII .30  Boyd's TH 100+ fpe
RWS D460  .177  
PP700 SA ,22 PCP pistol W/Rocker1 LDC & Red Dot
CP2 .22 Pistol/Carbine
SPA Varmint .177
Freedom 8 & Guppy CF Tank & 45 min SCBA
 https://www.zeemaps.com/map?

Offline Back_Roads

  • ???
  • GTA Senior Contributor
  • ******
  • Posts: 3789
  • Crosman BMG-1077
    • https://www.facebook.com/pg/longshot/about/
  • Real Name: James Seiler
Re: Adjustment / MOA question
« Reply #9 on: January 23, 2019, 07:26:36 PM »
ALso check that both rings are exactly the same height.
  • Wisconsin Collins ;Hunters Paradise; Theres a Sign in town to prove it :)
We Got The Guns !

Offline JimR

  • Plinker
  • **
  • Posts: 184
  • yes
  • Real Name: jim
Re: Adjustment / MOA question
« Reply #10 on: January 24, 2019, 07:58:10 AM »
Don, thanks. That sounds easy enough. James, The rings are new so I assume they are the same but I'll check them. Good point.

How do you word it... "Air Guns" or "AirGuns"?