Rifle Scopes Scope mount canted or not
- Thread starter lobo024
- Start date
Re: Scope mount canted or not
Take your dope per rifle to dial to 1000m. Then look at the travel specification of your applied optic (usually spec'ed at full travel). You initially assume half of that up, and half of that down or divide by two. Off the cuff, if this leaves you with less then ~15moa or ~4mil your will likely have issues at some point. Consider your optic zero (ex: 100m) and the fact that this will likely not be centered in your optic adjustment either helping or hurting your available elevation. Also consider changes per load and environment. The last consideration is that the the optic will lose windage adjustment at min and max elevations.
Take your dope per rifle to dial to 1000m. Then look at the travel specification of your applied optic (usually spec'ed at full travel). You initially assume half of that up, and half of that down or divide by two. Off the cuff, if this leaves you with less then ~15moa or ~4mil your will likely have issues at some point. Consider your optic zero (ex: 100m) and the fact that this will likely not be centered in your optic adjustment either helping or hurting your available elevation. Also consider changes per load and environment. The last consideration is that the the optic will lose windage adjustment at min and max elevations.
Re: Scope mount canted or not
I run at least 20moa cant on all my bases, and all my rifles are zeroed at 100, and i don't have any problems.
I run at least 20moa cant on all my bases, and all my rifles are zeroed at 100, and i don't have any problems.
Re: Scope mount canted or not
in addition, persoanlly, i don't see a reason to not put a 20moa on. The extra elevation travel is there when/if you need it, and it hasn't ever not allowed me to zero at 100 yds. JMO
in addition, persoanlly, i don't see a reason to not put a 20moa on. The extra elevation travel is there when/if you need it, and it hasn't ever not allowed me to zero at 100 yds. JMO
Re: Scope mount canted or not
On my worst case setup, the 20 MOA base has my scope almost bottomed out to zero at 100, so I essentially have a zero stop and maximum elevation adjustment available. Hmm.. maybe that's my best case setup!
On my worst case setup, the 20 MOA base has my scope almost bottomed out to zero at 100, so I essentially have a zero stop and maximum elevation adjustment available. Hmm.. maybe that's my best case setup!
Re: Scope mount canted or not
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lobo024</div><div class="ubbcode-body">I am building a .308 rifle with 24" barrel and my range limits me to a 1000 meters. I was wondering if really need a 20 moa cant on my scope mount or not </div></div>
The answer is simple, 50.4 MOA (14 Mils). Meaning if your scope has at least 50.4 MOA (14 Mils) of vertical adjustment, then your safe to use a 20 MOA (5.5 Mil) base.
By safely I mean able to use a canted base and still achieve a 100 yd zero, providing of course your receiver screw holes are square with the top of the receiver.
If your scope has at least 72 MOA (20 Mils), then you could safely use up to a 30 MOA (8.3 Mil) base.
If your scope has at least 93.6 MOA (26 Mils), then you can safely use a 40 MOA (11.1 Mil) base.
As to whether you need a 20 moa (5.5 Mils) base to reach 1000 meters with a 308, consider that a 175 SMK @ 2700 FPS would require around 44.2 MOA (12.9 Mils) to compensate for drop to 1000 Meters.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lobo024</div><div class="ubbcode-body">I am building a .308 rifle with 24" barrel and my range limits me to a 1000 meters. I was wondering if really need a 20 moa cant on my scope mount or not </div></div>
The answer is simple, 50.4 MOA (14 Mils). Meaning if your scope has at least 50.4 MOA (14 Mils) of vertical adjustment, then your safe to use a 20 MOA (5.5 Mil) base.
By safely I mean able to use a canted base and still achieve a 100 yd zero, providing of course your receiver screw holes are square with the top of the receiver.
If your scope has at least 72 MOA (20 Mils), then you could safely use up to a 30 MOA (8.3 Mil) base.
If your scope has at least 93.6 MOA (26 Mils), then you can safely use a 40 MOA (11.1 Mil) base.
As to whether you need a 20 moa (5.5 Mils) base to reach 1000 meters with a 308, consider that a 175 SMK @ 2700 FPS would require around 44.2 MOA (12.9 Mils) to compensate for drop to 1000 Meters.
Re: Scope mount canted or not
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BobinNC</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lobo024</div><div class="ubbcode-body">I am building a .308 rifle with 24" barrel and my range limits me to a 1000 meters. I was wondering if really need a 20 moa cant on my scope mount or not </div></div>
The answer is simple, 50.4 MOA (14 Mils). Meaning if your scope has at least 50.4 MOA (14 Mils) of vertical adjustment, then your safe to use a 20 MOA (5.5 Mil) base.
By safely I mean able to use a canted base and still achieve a 100 yd zero, providing of course your receiver screw holes are square with the top of the receiver.
If your scope has at least 72 MOA (20 Mils), then you could safely use up to a 30 MOA (8.3 Mil) base.
If your scope has at least 93.6 MOA (26 Mils), then you can safely use a 40 MOA (11.1 Mil) base.
As to whether you need a 20 moa (5.5 Mils) base to reach 1000 meters with a 308, consider that a 175 SMK @ 2700 FPS would require around 44.2 MOA (12.9 Mils) to compensate for drop to 1000 Meters.
</div></div>
Then there is my NF 8-32BR that I have to run with a 30MOA base to get to 1000.
I've related this story before. On the 308 that I shoot in F class I found that on a 20MOA base my 32BR 100 yd zero was 18.5 MOA off of the bottom. The scope only has 50 MOA of elevation and most 308s need close to 36MOA to get to 1000 yds. (50-18=32, not going to work) I'm running a 30MOA rail.
The answer is your mileage may vary, it depends on your rifle, load and scope, but you will likely be best off with a 20MOA rail.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BobinNC</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: lobo024</div><div class="ubbcode-body">I am building a .308 rifle with 24" barrel and my range limits me to a 1000 meters. I was wondering if really need a 20 moa cant on my scope mount or not </div></div>
The answer is simple, 50.4 MOA (14 Mils). Meaning if your scope has at least 50.4 MOA (14 Mils) of vertical adjustment, then your safe to use a 20 MOA (5.5 Mil) base.
By safely I mean able to use a canted base and still achieve a 100 yd zero, providing of course your receiver screw holes are square with the top of the receiver.
If your scope has at least 72 MOA (20 Mils), then you could safely use up to a 30 MOA (8.3 Mil) base.
If your scope has at least 93.6 MOA (26 Mils), then you can safely use a 40 MOA (11.1 Mil) base.
As to whether you need a 20 moa (5.5 Mils) base to reach 1000 meters with a 308, consider that a 175 SMK @ 2700 FPS would require around 44.2 MOA (12.9 Mils) to compensate for drop to 1000 Meters.
</div></div>
Then there is my NF 8-32BR that I have to run with a 30MOA base to get to 1000.
I've related this story before. On the 308 that I shoot in F class I found that on a 20MOA base my 32BR 100 yd zero was 18.5 MOA off of the bottom. The scope only has 50 MOA of elevation and most 308s need close to 36MOA to get to 1000 yds. (50-18=32, not going to work) I'm running a 30MOA rail.
The answer is your mileage may vary, it depends on your rifle, load and scope, but you will likely be best off with a 20MOA rail.
Re: Scope mount canted or not
You don't "need it" but it is sure nice not to be in the middle of the adjustment range. By adding the 20 moa to one end you have only a little bit of travel in the other directon, so it helps (if you don't have zero stop) to not get lost in rotation.
You don't "need it" but it is sure nice not to be in the middle of the adjustment range. By adding the 20 moa to one end you have only a little bit of travel in the other directon, so it helps (if you don't have zero stop) to not get lost in rotation.
