Getting more adjustment from optic.
- Thread starter Smurph_
- Start date
So the 5-25 has 70 MOA of internal adjustment, at optical center that's split 50/50 so if you were able to somehow zero dead nuts on OC you'd have 35 MOA of upward adjustment. Add in the 20 MOA base and in theory you'd have 55 MOA of adjustment, however the zeroing process tends to eat up a bit of that elevation.
6.5SH is correct also, if the scope base isn't bedded there's the potential that it could be flexing under the torque of the scope base screws, costing you some MOA. To check the fit of the base to the receiver, remove the 2 rear mounting screws and loosen the front two. Push the base forward, tighten the front screws to 15 in/lbs, and check for a gap at the rear between the base and receiver. If you see a gap, bed the base, it's not hard and everything you need can be picked up from Walmart.
6.5SH is correct also, if the scope base isn't bedded there's the potential that it could be flexing under the torque of the scope base screws, costing you some MOA. To check the fit of the base to the receiver, remove the 2 rear mounting screws and loosen the front two. Push the base forward, tighten the front screws to 15 in/lbs, and check for a gap at the rear between the base and receiver. If you see a gap, bed the base, it's not hard and everything you need can be picked up from Walmart.
You can also lose some MOA adjustment at the barrel. Not every barrel, especially factory is perfectly true to the reciever. It is not necessarily a bad thing, still within tollarance, but a reality you have to live with.
It is also possible there is pressure on the barrel from the stock somewhere moving POI and if you hang weight off the barrel end, like a suppressor, it will bend the barrel down a little, especially if the barrel is a thinner longer profile.
It is also possible there is pressure on the barrel from the stock somewhere moving POI and if you hang weight off the barrel end, like a suppressor, it will bend the barrel down a little, especially if the barrel is a thinner longer profile.
Trigger Monkey pretty much covered it but just to clarify you won’t get any worthwhile amount of elevation with different rings being lower or higher. So don’t worry about your ring height. As long as it’s comfortable then use them.
How far do you plan to shoot the rifle? You should get to 1000 yards around 35-40 moa with the .308 depending on load so you can get there and a little past but then you have more in the reticle to hold if needed.
How far do you plan to shoot the rifle? You should get to 1000 yards around 35-40 moa with the .308 depending on load so you can get there and a little past but then you have more in the reticle to hold if needed.
If it was me I would like a little cushion above what it takes to hit 1,000-ish yards so that I can be sure I'll have enough elevation in different temperature ranges. Colder weather generally means more dense air and more resistance on the bullet, which will require more elevation to hit a given distance. You could hand load to increase muzzle velocity and you might reduce the amount elevation you need to hit 1K a little bit and you might see a little bump in performance in the wind. At the end of the day though, it's a .308 slinging 175 SMK's, and elevation is really just numbers on a turret so I wouldn't focus on hand loading too much at this point.
Try bedding the scope base and see if that increases your amount of usable elevation If you're still sitting around 45 MOA, you can swap the base out for a 30 MOA base (I'd check it to see if it needed bedding too) and go from there. Another alternative is to use Burris Signature XTR rings with inserts that allow you to add MOA on top of what you have in the scope base. I use these on my .22's to give me enough elevation to dial past 400 yards and they work quite well. They have a 1" height for 30mm scopes which should work quite well with your set up from what I can see. Swapping the base or using the rings with the inserts are the quickest, least expensive ways to get you some more elevation compared to the drawn out process of hand loading to have a few MOA off your 1,000 yard dope.
Try bedding the scope base and see if that increases your amount of usable elevation If you're still sitting around 45 MOA, you can swap the base out for a 30 MOA base (I'd check it to see if it needed bedding too) and go from there. Another alternative is to use Burris Signature XTR rings with inserts that allow you to add MOA on top of what you have in the scope base. I use these on my .22's to give me enough elevation to dial past 400 yards and they work quite well. They have a 1" height for 30mm scopes which should work quite well with your set up from what I can see. Swapping the base or using the rings with the inserts are the quickest, least expensive ways to get you some more elevation compared to the drawn out process of hand loading to have a few MOA off your 1,000 yard dope.
I get that and I will definitely go with a steeper base first. Why would it take so much adjustment to get to 1000 though? Most of the dope charts I look at put the 175 around 35-40 MOA for 1000. I know that my rifle is going to behave a little different, but it seems like a pretty dramatic increase off of what is generally expected. It was about 70 degrees and dry that day too.
Have you gotten the muzzle velocity of that ammunition from your barrel? Are there a lot of rounds down the barrel? Did you verify the 1,000 yard target was really 1,000 yards? Have you verified the tracking of the scope? Are you keeping a data book?
No one is going to have any idea why it would take the amount of elevation it did for your rifle to hit 1,000 yards because the above questions are just some of the variables that can affect the outcome. Someone else's dope charts are ok to get you in the ball park but then you need to refine that and true it up based on your own observed data and log that in the data book. From there you're building your dope for your gun and all those other charts and what they say are irrelevant.
No one is going to have any idea why it would take the amount of elevation it did for your rifle to hit 1,000 yards because the above questions are just some of the variables that can affect the outcome. Someone else's dope charts are ok to get you in the ball park but then you need to refine that and true it up based on your own observed data and log that in the data book. From there you're building your dope for your gun and all those other charts and what they say are irrelevant.
Last edited:
Yes you will get more velocity loading. FGMM is decent but usually slower. Using a better higher BC bullet and loading you will get it down. My 20” .308 only takes about 36 moa to 1000. You should chrono your rifle though so you know what it is doing from it.
Similar threads
