Rifle Scopes anyone know the size of a 20 moa base?

[jimi]

hey guys, im just trying to work out if the EGW one piece base that came with my howa is 20 MOA or not,

yes it looks declined down towards the front, but the rear of a howa action is much lower than the front. so it actually looks like it sits parallel to the bore. but this may be an optical illusion.......?????

so what im after is how thick the rear of your base is (right behind the rear most screw)between the top of the reciever and the inside of the groove where your rings would sit into.

not sure if there is a mathmatical way to convert MOA to mm or .000 of an inch etc, for a declined base. im not that clever. hahahaha

cheers, and sorry if none of that makes any sense....im from AUSTRALIA

jimi

 

[The_FNG]

Re: anyone know the size of a 20 moa base?

Shouldn't it be higher at the front not lower??? ie - inclined.

 

[Plange]

Re: anyone know the size of a 20 moa base?

Higher in the back(towards shooter) and lower in the front. The canted base allows you more elevation in order to shoot out further.
If the base slopes downward you would need to lift your rifle up to make longer shots.

Usually there is a stamp of some sort on the base itself, or if you have a part number of the base you can research it that way.

 

[jimi]

Re: anyone know the size of a 20 moa base?

no such luck, it says nothing about being 20 MOA, so i assume it isnt, as my nightforce rail says 20 MOA on it. i might just see if i can work out how thick the front vs the rear is on the nightforce, and shim the rear of the EGW base to roughly match... get all down and dirty on it... ill let you know how it goes....

besides, getting rifle parts in australia is becoming more and more of a hassle, so if i can shim it to about 20 MOA ill let you guys know how it turns out... and how rough and ready it looks.

jimi

 

[AXEMAN]

Re: anyone know the size of a 20 moa base?

level a table. place the base on the table. place the level on the base. or measure the front and back

 

[jeo556]

Re: anyone know the size of a 20 moa base?

I just bought a EGW 20 moa base and it says such on the bottom of the base. If your base doesn't mention it it's probably not.

 

[jimi]

Re: anyone know the size of a 20 moa base?

yeah thats what i worked out.

also as mentioned, even on a 0 MOA cant base, it is still not level due to the reciever not being level.

jeo, do you think you could give me a rough measurement of how thick the rear of the base is so i can have a try at shimming the base up a bit to gain some more elevation?

cheers

jimi

 

[AXEMAN]

Re: anyone know the size of a 20 moa base?

someone will chime in. its been discussed. its a minor fraction. brownells sells shims for this. not suggesting you buy, but they may be able to give you the info on the thickness needed

 

[The_FNG]

Re: anyone know the size of a 20 moa base?

That Howa has been giving you hell since you got it, hasnt it mate lol

 

[jimi]

Re: anyone know the size of a 20 moa base?

not the gun, just the gun/scope relationship.

i ended up getting bored before work last night (story of my life) and went ahead and disassembled the scope base off the rifle,

cut up a coke bottle(has a nice curve to the plastic already which actually almost perfectly matched the curve of the rear of the reciever). cut it to the right size, used 3 layers, drilled out some holes for the mounting screws to go through and mounted it back up.

took about 30 minutes.

was just bore sighting it out the window before at about 100 meters and i seem to have done almost exactly 20 MOA right off the bat!!! i got about 1 1/2 more turns down than where it was before so now its right in the middle of the elevation range. siting dead on the silver mark on the inside of the turret under the knob, which i assume denotes halfway elevation.

sure i could chuck another shim in there, but ill see how these ones hold up. it seems to have tightened down pretty damn snug, and the bolt still cycles smooth.

these groups were just for my own confirmation before i changed anything to the base. shot yesterday. yep 3 shot groups, but the top right one was 6 shots, and also 2 different tytpes of head stamped federal cases FC and LC(just for shits and giggles to see how they overlapped each other. also there are numerous windage and elevation shifts due to me being an idiot and trying to get a perfect 100m zero, but with turrets that turn opposite ways to every scope i have ever used....damn euro optics, lol

note to self, read the numbers THEN turn the turrets

so yeah, the howa can still shoot as of yesterday, but we shall see how it does after this Shim Job (sorry, couldnt help myself )

 

[AXEMAN]

Re: anyone know the size of a 20 moa base?

you may be able to bed the rest of the gap in there with something. pretty easy. if you need me too, i will measure the front and back of my 20moa and length. that will give you the angle. but you have it down.

 

[jimi]

Re: anyone know the size of a 20 moa base?

thanks, but i just took it out today to resight in with the shim, and it seems to be going perfect, i also gave it a ghetto drop test to check its shock handling ability and it was perfect.

think ill just leave it now unless something dramatic happens, lol

ill put up some pics of how these groups look. solid .30MOA and under if im really lucky

jimi

 

[Lindy]

Re: anyone know the size of a 20 moa base?

Well, if you're still interested in the math, here's how to calculate the measurement if you want to.

There are 60 MOA in one degree.

So, the formula is:

Incline = tangent( MOA / 60) X base length

tangent(0.3333) = 0.0058

So, if your base is 5 inches long, the back would be higher in the front (0.0058 X 5) = 0.0291, or about 30 thousandths of an inch.

 

[jimi]

Re: anyone know the size of a 20 moa base?

wow, my brain hurts just thining about it...

also those groups i mentioned are more like .22" wooo

jimi