CZ 457, Bergara B14R, or....?

[Uncle Duke]

If you find yourself in need of MORE elevation dial, with a 20moa rail and the scope you are using, you need MORE cant in the rail not less. My 20 gets me dialed on at 300 to 350 depending on ammo and conditions before I bottom out the 4-20 Burris xtr2 that was on the rifle. I kicked around a 30 but that was about when I pulled that action out of the chassis and dropped a centerfire in it.

Yep!

Here's a good explanation from Warne, as this rail cant topic can be confusing to a lot of people. Note that the "600 yards" mentioned is a rough guesstimate example for centerfire, not .22 rimfire where 300 or so as mentioned above becomes reality.

20 MOA Explained

There are many misconceptions in the world about what a 20MOA base does. Many of those misconceptions stem from perceptions about what a 20MOA base is capable of providing, and when it is needed on a rifle. Many shooters who want to shoot long range automatically assume they need a 20MOA...

warnescopemounts.com

 

[trickg]

If you find yourself in need of MORE elevation dial, with a 20moa rail and the scope you are using, you need MORE cant in the rail not less. My 20 gets me dialed on at 300 to 350 depending on ammo and conditions before I bottom out the 4-20 Burris xtr2 that was on the rifle. I kicked around a 30 but that was about when I pulled that action out of the chassis and dropped a centerfire in it.

Help me try to understand this - should the highest point of the scope rail be towards the front or the rear? The higher you raise the rear, does that not equate to needing more elevation, not less? I had to dial up a fair bit just to get to zero. Raising the rear of the scope effectively drops the point of aim, right?

 

[4g64loser]

Help me try to understand this - should the highest point of the scope rail be towards the front or the rear? The higher you raise the rear, does that not equate to needing more elevation, not less? I had to dial up a fair bit just to get to zero. Raising the rear of the scope effectively drops the point of aim, right?

You want the centerlines of the optic and the bore to converge at a closer point on the objective lens/muzzle end to afford you more remaining elevation dial given the same optic internal.travel. the catch is that with too much cant you won't be able to.zero the rig close in. Usually 50yds gets dicey with the 22s in the 30-40moa base range, scope depending...

If you are zeroed at 50 currently, slip your turret to zero if you haven't done so already. Lock it down. Dial up until you hit your erector tube stop. Record this value. Subtract the value from the published total internal elevation adjustment value (see manufacturers website or your manual). If the difference is less than the INCREASE in base inclination you want to go to, it should work.

 

[hammer67]

Think of it this way- If you are shooting at 200 yards, where does the barrel need to point? up above target a little. where would scope point? It would be on target. The further distance, the more barrel needs to point up. Do you have enough adjustment in scope to keep it on target as continue to raise barrel up at increasing distances. If not, then need rail that will point scope down more. But then may be limited at closer distances. I think Need to decide max distance want to shoot, look at bullet drop at that distance and how much adjustment your scope has. Then decide if want angled mount.

Edit: this was more thinking 223 not 22. If 22 the part about where would barrel point would not be a little above target, it would be a lot cause of the significant drop of 22 at that distance.

22lr 40gr round nose at 1255 fps bc 0.128, with a 100 yard zero, will be 31.6" low at 200. That per mcarbo chart i got with a purchase. 17 hmr is 8.54".

 

[Hector J Medina G]

Trickg;

You COULD also try ADJUSTABLE mounts.
There are all sorts of designs and prices, from the extremely inexpensive SportsMatch / Vector Optics, through the WestHunter's, through the Eratac, and the Ivey would be the top. From $60 to $1,500
Some of them are good, even the inexpensive ones if you are going to decide on ONE compensation value (whatever that is: 20,30,40 or 50 MOA), some of them provide versatility and reliable adjustment on the fly, at a price.

What is important is to start from an OPTICALLY centered scope, and for that you need some "V" blocks, you can even make them yourself out of hardwood, just make sure they are reasonably smooth.
Mount the scope on the blocks and sight a far away object.
Then turn the scope 180 degrees and see where the POA is. Adjust and repeat. Then do it for the windage.
When the scope can be turned a full turn with the POA not changing, you have found the OPTICAL center.
In GOOD scopes the OPTICAL and the MECHANICAL axes will not be too far off, but you may be surprised by what you find.

You will also need to decide how much of the total drop at your longest distance you are going to take with the reticle.

For Example, my old HorusVision with the offset center crosshairs allows 46 mRads of hold-off vertically (that's more than 150 MOA) @ 4X, proportionally less at higher magnifications.

IF I can resolve the details of an 8" target at 300 yards ( it's a 2 1/2 MOA target, and this will depend on your eyesight and your glass), then you can shoot with some confidence at 10X, which would allow me to see about 17 1/2 mRads (60 MOA) only holding off.

For 300 yards, from an 80 yds zero, in my setup, I can hold off at 16X out to 300 yards using ONLY the reticule (-12 mRads). If it gets too windy, I reduce the mag to 12X and get the whole range of wind hold-offs.

I don't have access to 500 yards, but the results to 300 are actual firings, not calculated.

Now, according to my app (and now we enter the realm of calculations).
For 500 yards I would require 21.6 mRads of holdover.

And that, truly is a bit much, which would require me to re-think the 80 yards zero.

The 80 yards zero is useful because I can get "on paper" shooting at 19 yards (first zero), and then refine the 80 yards one. It is also useful because the Apex of the trajectory holds at +1 mRad from 30 to 45 yards; from 45 to 60 you can comfortably take the shoots at +3/4 mRad, form 60 to 85 yds you can aim dead on, and so on. If you have smaller targets, then you need to analyze what YOU need.

Part of the fun is finding what works for YOU.

Best of lucks, thanks for keeping us posted, keep well and shoot straight!



HM

 

[Russ D]

I’m shooting a 20 moa base on my Bergara and with an Arken scope I can easily shoot to 400 yards using the turrets and the reticle. You don’t need to change anything.

 

[trickg]

I’m shooting a 20 moa base on my Bergara and with an Arken scope I can easily shoot to 400 yards using the turrets and the reticle. You don’t need to change anything.

It's not going to be an issue - I zeroed at 50 without issue, and I have plenty of room to dial up to 100 - I seriously doubt I'll ever shoot this gun beyond that, and If I really need to, I can figure out my reticle holds. That's what I was doing yesterday. The missus and I were playing battleship with targets on a stand at 50, but I had tossed a couple of shotshell hulls onto the berm at 100, and I was shooting those and making them jump, using just the reticle hashes.

It's decently accurate - I wasn't trying to shoot bug holes yesterday, and I still have a bunch of that Winchester High Velocity ammo to burn up. For what we were doing, that rifle is probably overkill.

 

[Hector J Medina G]

" I had tossed a couple of shotshell hulls onto the berm at 100, and I was shooting those and making them jump, using just the reticle hashes."

That's the spirit!

Try with spinners (if your club allows metal in the ranges), targets tossed in the ground present a much larger area than when suspended.

;-)

Keep up the good work!




HM

 

[trickg]

That's the spirit!

Try with spinners (if your club allows metal in the ranges), targets tossed in the ground present a much larger area than when suspended.

;-)

Keep up the good work!

HM

I saw someone with a spinner setup at the 50 yard distance at the 100 yard range yesterday - just checked the range rules, and those are in fact allowed, so that's something to consider, although if I did get something like that, I'd likely stage it out at the 100 yard line - hitting something like that at 50 isn't much of a challenge with this rifle.