If I switch from a 0 moa base to a 20 moa base should my 100 yd zero require roughly 20 moa less elevation? That's how I've always understood things to work. Over the winter I did just that swapping a 0 moa EGW base for a 20 moa EGW. Last year I had a Bushnell 10X40 on the 0 moa and my 100 yd zero was roughly middle of my elevation travel. Now I have an NXS 8-32X56 in NF low rings on the new 20 moa base and I'm at roughly half my 65 moa travel with a 100 yd zero. I have 34 moa left. I figured I'd have more than that. The base cants .010" over a 4" span, is that normal?
Question about 100 yd zero with 20 moa base
- Thread starter supernova
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ultimate_monkey
CGN Ultra frequent flyer
- Location
- victoria BC
Nope .010 over 4" sounds more like a 10 moa base
(Using 1" as 1moa not 1.047")
- 1moa /300'= .003" per foot /12 =.0002" per inch x4"of rail = .001 for every moa x20 = .022" on the rail for 20moa
That of course if your sure the rail is exactly .010 over 4"
Also . Are you sure the base is machined perfectly fit to the receiver ? If you have a gap on the back, tighten that down , the snug the front up , you essentially cut down the amount of moa in the rail , if that makes sense ? As the base is now sloping back some
(Using 1" as 1moa not 1.047")
- 1moa /300'= .003" per foot /12 =.0002" per inch x4"of rail = .001 for every moa x20 = .022" on the rail for 20moa
That of course if your sure the rail is exactly .010 over 4"
Also . Are you sure the base is machined perfectly fit to the receiver ? If you have a gap on the back, tighten that down , the snug the front up , you essentially cut down the amount of moa in the rail , if that makes sense ? As the base is now sloping back some
It was a nice fit front and rear when I mocked it up, no gap. I get what youre saying, the rear of the rail gets pulled down causing less overall cant. Sorry to say but I think I just crossed EGW off my list... I remember something like one thou over 4" equalling about 1 moa cant for shimming bases but I'm not a fan of that. Sucks that I've bought two of these things, I wish I'd caught this sooner but it was done over the winter and has been sitting since. Given that the base was missing its hardware and the shop I bought it from had to source replacements for me now this... Never again. Thanks for the help UM.
ultimate_monkey
CGN Ultra frequent flyer
- Location
- victoria BC
Well givin the situation . Rather the shim it , shim it with bedding. Iv done it a few times and it's working out great . At this point ill just assume you know how to bed a scope rail , it's done the exact same way but set the shim (thin thin washers) into the bedding compound then when the bedding cures the shims are never to be seen and the rail has 100% support . Cheap fix for a "cheap" rail
That's funny, I've been thinking about doing just that now. I might give it a try... There really aren't a lot of options for 1 piece bases for the Howa 1500 and the ones that are out there would need taller rings. Have you had any issues with misaligned bolt holes after shimming? Is there much of a limit to how far I can go? Thanks for the help!
ultimate_monkey
CGN Ultra frequent flyer
- Location
- victoria BC
Iv never had a problem on my 308 , the egw bolt holes are slightly oversized in my experience so unless youg trying to shim like 1/8" or something ridiculous you shouldn't have a problem , I dry fit mine all together befor using the bedding compound to make sure that I won't have any silly binding issues with the base screws or any thing , iv shimed the one on my .22 about .020" ontop of a 20moa rail to push it way out and thousands of rounds lates it's doing just fine
