If you shim the front of a scope base higher does that raise the point of impact higher or lower?
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Rifle Scopes shim scope base?
- Thread starter hawkinpup
- Start date
Re: shim scope base?
Why would you shim your scope base? Buy a 20MOA or more base to suit your needs, or buy offset MOA rings, if your shimming the base how would you plan on doing this when the bases are machined to to fit your action radius fairly precisely?
If you have 4 screws how do you plan to shim all 4 evenly so you are not putting a bind on the base? There is no way to precisely torqe the screws to the appropriate settings with shimming without the screws loosening up over time.
I think this is a bad idea, but let us know how it works out.
Why would you shim your scope base? Buy a 20MOA or more base to suit your needs, or buy offset MOA rings, if your shimming the base how would you plan on doing this when the bases are machined to to fit your action radius fairly precisely?
If you have 4 screws how do you plan to shim all 4 evenly so you are not putting a bind on the base? There is no way to precisely torqe the screws to the appropriate settings with shimming without the screws loosening up over time.
I think this is a bad idea, but let us know how it works out.
Re: shim scope base?
Agree with NF31780. Don't shim a base. It used to be done 'back in the old days' on deer rifles, especially with some of the older scopes that didn't have the same range of adjustment as we have now. On rifles that got shot 10 or 20 times a year, it usually held up.
But now the right stuff is available, the right bases, rings, etc. All that has come a long way.
Also as NF said, shimming will not likely hold position through any serious shooting.
Cheers, Sirhr
Agree with NF31780. Don't shim a base. It used to be done 'back in the old days' on deer rifles, especially with some of the older scopes that didn't have the same range of adjustment as we have now. On rifles that got shot 10 or 20 times a year, it usually held up.
But now the right stuff is available, the right bases, rings, etc. All that has come a long way.
Also as NF said, shimming will not likely hold position through any serious shooting.
Cheers, Sirhr
Re: shim scope base?
I have a Weatherby Vanguard 308 24" #7 heavy varmint barrel, I installed a Leupold 3.5x10x50 scope, ken ferrell base (10 moa) and low tps rings. I am trying to sight in at 100 yards still hitting about 2 feet high, but the turret is cranked all the way down? I have taken it apart and checked for burrs on the scope base and rings, lapped the rings, and reinstalled it but still hitting high.
I have a Weatherby Vanguard 308 24" #7 heavy varmint barrel, I installed a Leupold 3.5x10x50 scope, ken ferrell base (10 moa) and low tps rings. I am trying to sight in at 100 yards still hitting about 2 feet high, but the turret is cranked all the way down? I have taken it apart and checked for burrs on the scope base and rings, lapped the rings, and reinstalled it but still hitting high.
Re: shim scope base?
Call Near Mfg. and talk with Richard. He's a super nice guy, and his bases and rings are second to none.
Call Near Mfg. and talk with Richard. He's a super nice guy, and his bases and rings are second to none.
Re: shim scope base?
Howa has a One in 2xx-400 gun thing where they need a 20 moa base to zero the gun in. No explanation but they are out there.
IF they can point down it is logical that they on occasion could have a one in 800 thing where the barrel points up.
If your scope works on other guns with no issues and the mount seems correct in this case it may be the gun.
geo
www.egw-guns.com
Howa has a One in 2xx-400 gun thing where they need a 20 moa base to zero the gun in. No explanation but they are out there.
IF they can point down it is logical that they on occasion could have a one in 800 thing where the barrel points up.
If your scope works on other guns with no issues and the mount seems correct in this case it may be the gun.
geo
www.egw-guns.com
Re: shim scope base?
hawkinpup.....
In answer to your question, raising the front will make you hit lower.
Sounds like a gun problem, but I would try another scope, if you can borrow one, to make sure.
If it's the gun, call Weatherby and ask them what they will do about it, they'll probably make it right.
If not, you'll have to bed the base (I'd sell the one you have and get a 0 MOA to start) to fix the problem correctly.
hawkinpup.....
In answer to your question, raising the front will make you hit lower.
Sounds like a gun problem, but I would try another scope, if you can borrow one, to make sure.
If it's the gun, call Weatherby and ask them what they will do about it, they'll probably make it right.
If not, you'll have to bed the base (I'd sell the one you have and get a 0 MOA to start) to fix the problem correctly.
Re: shim scope base?
thankyou hellbender (great username by the way) I'm trying a couple of options right now i'll post results
thankyou hellbender (great username by the way) I'm trying a couple of options right now i'll post results
Re: shim scope base?
Shimming a scope base is like putting a band-aid on a cut that needs stitches. You have a problem some where. Probably in the action. But regardless of where the problem is-fix it. Do not put a band-aid on it. Tom.
Shimming a scope base is like putting a band-aid on a cut that needs stitches. You have a problem some where. Probably in the action. But regardless of where the problem is-fix it. Do not put a band-aid on it. Tom.
Re: shim scope base?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hawkinpup</div><div class="ubbcode-body">I have a Weatherby Vanguard 308 24" #7 heavy varmint barrel, I installed a Leupold 3.5x10x50 scope, ken ferrell base (10 moa) and low tps rings. I am trying to sight in at 100 yards still hitting about 2 feet high, but the turret is cranked all the way down? I have taken it apart and checked for burrs on the scope base and rings, lapped the rings, and reinstalled it but still hitting high.
</div></div>
The base iis on correctly right?You dont have it on backwards?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hawkinpup</div><div class="ubbcode-body">I have a Weatherby Vanguard 308 24" #7 heavy varmint barrel, I installed a Leupold 3.5x10x50 scope, ken ferrell base (10 moa) and low tps rings. I am trying to sight in at 100 yards still hitting about 2 feet high, but the turret is cranked all the way down? I have taken it apart and checked for burrs on the scope base and rings, lapped the rings, and reinstalled it but still hitting high.
</div></div>
The base iis on correctly right?You dont have it on backwards?
Re: shim scope base?
still trying all the suggestions, no the base is not on back wards, and don't worry folks I won't shim the base, just trough it out there because I never heard of it before.
still trying all the suggestions, no the base is not on back wards, and don't worry folks I won't shim the base, just trough it out there because I never heard of it before.
Re: shim scope base?
I tried another scope but that too was cranked all the way down. would higher rings help? I'm using low tps rings right now
I tried another scope but that too was cranked all the way down. would higher rings help? I'm using low tps rings right now
Re: shim scope base?
If memory serves, if you shim the front ring on the bottom it will make the scope look higher than the bore axis therefore you will shoot lower. We shimmed my brothers SPS tactical scope with 0.030" shim stock a few years ago for the same exact reason and after many hundreds of rounds it has not moved.
If memory serves, if you shim the front ring on the bottom it will make the scope look higher than the bore axis therefore you will shoot lower. We shimmed my brothers SPS tactical scope with 0.030" shim stock a few years ago for the same exact reason and after many hundreds of rounds it has not moved.
Re: shim scope base?
Shimming a 1 piece base is ok, shimming the rings is not (order burris rings with moa inserts)
Brass shims work well or order some from Brownells
Shimming a 1 piece base is ok, shimming the rings is not (order burris rings with moa inserts)
Brass shims work well or order some from Brownells
Re: shim scope base?
Shimming scope gives you inconsistent and likely non-repeatable results with movement, removing scope, etc. Have to agree at a 20 MOA base.
Shimming scope gives you inconsistent and likely non-repeatable results with movement, removing scope, etc. Have to agree at a 20 MOA base.
Re: shim scope base?
His 10MOA base is too much for a 100yd zero, even with a zero moa base it will still hit 14" or so high, i think his only bet is to shim the front or go with Burris MOA rings.
??????
His 10MOA base is too much for a 100yd zero, even with a zero moa base it will still hit 14" or so high, i think his only bet is to shim the front or go with Burris MOA rings.
??????
Re: shim scope base?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Santo</div><div class="ubbcode-body">If memory serves, if you shim the front ring on the bottom it will make the scope look higher than the bore axis therefore you will shoot lower. We shimmed my brothers SPS tactical scope with 0.030" shim stock a few years ago for the same exact reason and after many hundreds of rounds it has not moved. </div></div>
Still shooting 0.5 inch groups after a few years, I would say that's repeatable.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Santo</div><div class="ubbcode-body">If memory serves, if you shim the front ring on the bottom it will make the scope look higher than the bore axis therefore you will shoot lower. We shimmed my brothers SPS tactical scope with 0.030" shim stock a few years ago for the same exact reason and after many hundreds of rounds it has not moved. </div></div>
Still shooting 0.5 inch groups after a few years, I would say that's repeatable.
Re: shim scope base?
hawkinpup...
Higher rings won't change anything (well, it will move you on paper the add'l height of the rings, say 1/8-1/4" or whatever).
The base could be bad, but not likely.
Are both rings the same height, (it's possible to mix a low and med in the same box)?
Some choices you have are (in the order I would do it)...
1. Send the rifle back to the maker for repair.
2. If you don't want to do that, bed the base (get new 0 MOA base first) higher in the front.
You can gain 20 MOA with a set of Burris posiline rings, but that won't be nearly enough with what you are telling us.
You need to be a bunch the other way if you want to be able to dial past 400 yards.
Not meaning to be a smart aleck, BUT...You're SURE you're turning the scope the right way, correct?? You moved it the other way and it moved the bullet impact lower, right?
hawkinpup...
Higher rings won't change anything (well, it will move you on paper the add'l height of the rings, say 1/8-1/4" or whatever).
The base could be bad, but not likely.
Are both rings the same height, (it's possible to mix a low and med in the same box)?
Some choices you have are (in the order I would do it)...
1. Send the rifle back to the maker for repair.
2. If you don't want to do that, bed the base (get new 0 MOA base first) higher in the front.
You can gain 20 MOA with a set of Burris posiline rings, but that won't be nearly enough with what you are telling us.
You need to be a bunch the other way if you want to be able to dial past 400 yards.
Not meaning to be a smart aleck, BUT...You're SURE you're turning the scope the right way, correct?? You moved it the other way and it moved the bullet impact lower, right?
Re: shim scope base?
this might be a stupid question, but im going to ask it anyways. any chance that the barrel is bent? a friend of mine bought a brand new sako 75 once and after all the bs he went through, he found out the barrel was bent.
this might be a stupid question, but im going to ask it anyways. any chance that the barrel is bent? a friend of mine bought a brand new sako 75 once and after all the bs he went through, he found out the barrel was bent.
Re: shim scope base?
OK I changed the Base to a 0 moa and it's hitting perfect. Now I dont know if the Ferrell base I had was messed up but it came down alot with the new base.
Thanks for all the input I really appreciate it
OK I changed the Base to a 0 moa and it's hitting perfect. Now I dont know if the Ferrell base I had was messed up but it came down alot with the new base.
Thanks for all the input I really appreciate it
Re: shim scope base?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hawkinpup</div><div class="ubbcode-body">If you shim the front of a scope base higher does that raise the point of impact higher or lower? </div></div>
POI would be lower. Think about it. Keep the scope pointing at the same place on the target then lower the barrel of the rifle. It would be pointing lower.
Not sure why you'd want to shim the front of the base though...
Whoop - just saw why you'd thought of doing that. Glad to see that it worked out.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hawkinpup</div><div class="ubbcode-body">If you shim the front of a scope base higher does that raise the point of impact higher or lower? </div></div>
POI would be lower. Think about it. Keep the scope pointing at the same place on the target then lower the barrel of the rifle. It would be pointing lower.
Not sure why you'd want to shim the front of the base though...
Whoop - just saw why you'd thought of doing that. Glad to see that it worked out.
Re: shim scope base?
i'm new to the whole MOA thing and getting my head around it but isn't 1 MOA at 100yrds 1"? So if you're scope is zeroed on a 0 MOA base and you switched to a 20 MOA base your POI would be 20" high?
I was under the impression you would use a 20 MOA base for long range shooting to reduce the amount of scope adjustment, or am i off the mark.
i'm new to the whole MOA thing and getting my head around it but isn't 1 MOA at 100yrds 1"? So if you're scope is zeroed on a 0 MOA base and you switched to a 20 MOA base your POI would be 20" high?
I was under the impression you would use a 20 MOA base for long range shooting to reduce the amount of scope adjustment, or am i off the mark.
