Gun check, scope check. Now what?

[adjuster1111]

Newbie here putting together my first long range setup and I'm wondering about the rings, and how to set the scope "true to the earth".

I'm working with a CA TFM, 6.5 PRC, a Sig 3BDX scope, Sig Kilo 2400 BDX for distance and have a Kestrel model 0857ALBLZ coming for wind/weather.

I'm stumped on what kind of rings and what height. Do you just order 3 sets of whatever and pick the ones that fit best or is there a fitment guide to suggest. The gun has a crank-a-stock, but would like it lower rather than higher.

Also looking for bipod advice. I will be using it 50% hunting, antelope, coyotes, etc, and 50% off a bench. Would probably prefer carbon but it's not a deal killer.

Regarding leveling the scope, what methods, or is there a device you recommend.

Initially sticking with Hornady Factory 147 Gr Eld Match or 143 Gr Eld-X.

I appreciate your wisdom and advice.

 

[zach_destroys]

Not much wisdom or advice from me on rings for that combo, but this is how I level my scope. Most of my shooting is from a bipod, so I set the rifle on the floor of my basement which I know is perfectly level. I then hang a string with a weight on the end from the ceiling at the other end of the basement, I align my vertical crosshairs with that string and torque everything. Having parallax that adjusts very close is helpful. Bubble levels will be added soon for when I'm shooting off uneven ground or a backpack.

 

[zach_destroys]

What size is the objective on that optic? If it's 50mm or less medium rings should work. No reason to go to highs I don't think. With heavier barrels and larger objectives (44-50mm) low rings often won't work.

 

[adjuster1111]

52MM.

Is it really just trial and error?

Thanks for the mount advice.

 

[TRyan]

Look at American Rifle Company website. The ARC M10 rings are among the best out there. The site has directions for sizing rings using your scope sitting on pennies on top of your rail. Super easy.

 

[Tiny Tim]

So many variables to consider for ring height. If you do some digging on your preferred ring manufacturers website, you can usually "figure it out". A rail will typically allow the use of a slightly lower ring. Seems that it is relatively rare for scopes used for "long range" to fit in a low ring. Medium rings work well for a vast majority. Zach has it right for leveling with a plumb bob and string. FWIW, choosing ring height is probably my least favorite part of a rifle build. Good luck.

 

[adjuster1111]

I really like that penny method.

 

[Bang4theBuck]

the penny method is really easy and works well. If you really want to get tricky, you can use replace one of the pennies with a new dime, or do one fewer penny in the front stack to simulate a canted rail.

 

[jd5521]

Scope Ring Height and Clearance Calculator

 

[jreagle]

I am guessing that everyone has different ways to go about it. Here is my method in case you may find it helpful.

Most of the time i will buy a low and medium height set of rings to start with for a scope with a 30mm tube and 42mm to 52mm objective lens, trying to mount the scope as low as possible on a rifle that does not have an adjustable comb or planning on raising the comb with after market devices.

First, a trial mount of the scope in the low rings to check how, when moving the it back and forth to obtain the correct eye relief and cheek weld, it all affects the objective bell clearance between the end of the rail and barrel shank with proper eye relief and alignment to the eyepiece of the scope. Depending on how the comb of the stock is shaped/cut and its relation to the bore and where your cheek rests with proper eye relief will determine your final choice of the ring height. Set it up then recheck, closing eyes and bring up the rifle to the natural position with proper cheek weld on to the stock, open eyes and see where the scope landed. If out of position, move the scope for proper eye relief at high and low power, or change to higher rings if scope landed too low and try again until all is satisfactory. Once i am satisfied with the position, then mark the scope with a pencil bracketing the ring location.

Next, the leveling process for the rifle and scope, bore and scope alignment, and a plumb check with the reticle; which all is somewhat involved in itself and another conversation, before finally tightening the rings. There was a very informative thread on here awhile ago discussing the scope leveling process others are using.

The rings i dont use i will save for the next rifle, buying a set of either low or mediums, replacing the rings i used on the rifle before.

 

[adjuster1111]

Thank you for that.

I need to do some noodling around here for the plumb check method, as I should have all the parts, to start mounting soon.

 

[adjuster1111]

Those Arc M10 rings are money!

They mounted up nicely.

 

[TRyan]

Those Arc M10 rings are money!

They mounted up nicely.

Heck yeah, they are sweet! I won't use anything else now. Love mine.

 

[TexasSportsman]

What size is the objective on that optic? If it's 50mm or less medium rings should work. No reason to go to highs I don't think. With heavier barrels and larger objectives (44-50mm) low rings often won't work.

You're right. Your gunsmith can set the scope you want to buy on your rifle with low/med/high mounts to see how close the scope is to the barrel. The scope should never touch the barrel. If the scope needs to be mounted closer to the rear of the rifle a larger objective lens may now allow it and you may not have the proper eye relief which is the distance between the ocular lens and your eye.

Unless your rifle has an adjustable comb you really should not go with high scope mounts and an objective lens larger than 44mm. Your face should rest firmly on the stock...a good cheek weld. If you have to raise your face to see though the scope it is mounted too high and your accuracy will suffer.

All of my rifles have an objective lens of 44mm or smaller. If I were to go to a larger objective lens I'd opt for a a cheek pad or a rifle with an adjustable comb as shown on the second image. With that feature you can mount a fairly large scope or replace the stock.

If your rifle does not have an adjustable comb then add a cheek pad to the stock so it'll give you the height you need to see through the middle of the scope on low and high power or replace the stock.