Help with info on dialing in MOA 2nd focal plane scope

[Newbweatherby]

thanks will the 20moa base piece help at all?If I could I would have bought a swavorski x5 or better but the minox is my limit and Ian still paying for it ,500 meters steel rams no problem on a rest not free hand I can do 4 out of 4 obcebive dialed in the right loads of course.I thought the Minox had more adjustment but o m probably wrong in it.

 

[adam]

The 20 moa base will be the thing that allows it to work at all. If you are hitting 500 meter rams, that is a good sign. Set up on a quality bipod with a rear bag and practice. Your caliber is flat shooting, so that also helps.

The reality is the game gets more difficult past 600. Most people assume it's caliber and accuracy and a whole bag of things...it is...those are all ingredients.

Past 600 yards, time of flight magnifies and compounds all of the other errors and mistakes we make. You can make a lot of mistakes inside of 600 and still be very successful. That's what makes it so fun, because 600 is still a pretty far poke. It's easy to forget that in the armchair.

Short answer here is: stop stressing about what you bought....sounds like it's too late... focus on adding the other components that will stretch your distance. Shoot that thing at range and find out.
Practice (or group size-reloading skills)
Quality Bipod
Good rear bag
Cheek weld (this one is often overlooked)
Range finder
Ballistic app. Many good ones. I like "shooter"

 

[BallisticsGuy]

1, I would absolutely NOT use a 20MOA base unless you only have 6-7MOA of up left in the turrets right now with a 100yrd zero. That's bad advice IMO as it ignores the fact that the total adjustment of the scope is 26MOA. If you're centered right now then you'll be 7MOA high at 100 yrds and not be able to fix that. That makes for a forced 500yrd zero.

Regarding Sniper101, Rex's focus is purely on practical uses of a rifle against animate targets (including targets that might shoot back) under field conditions. For that a FFP tactical scope is optimal because his use case suggests that ranging with the reticle is going to be part of the activity. That said, he discusses both pretty extensively. Enough that most questions are answered if you pay attention. I'll go further for you, try to make you life easy.

Your Minox is NOT going to be a problem. You can really easily dial in a few minutes in the mounting system. Before I tell you exactly how I need to know where you're at in the scope at your zero... how much up you have left. Once I have that data I can tell you exactly what you need. My hunch is that you'll be right off the bat but that a set of Burris Signature Series 30mm Zee rings and a set of their eccentric inserts in 0MOA and 10MOA might stretch you out to 1500yrds or more between reticle and turrets. We should be able to get you set up so you can dial to 1000yrds or slightly more and still have a 200yrd zero with ~1" above line of sight at 100yrds.

From my initial checking and some ballpark-y ballistics numbers I did for you it looks like you're set up as follows on your BDC reticle (BDC indication = Actual range - MOA value). Numbers below are for a 185gn low drag bullet at 3250fps:
100yrd dial .75MOA down (6 clicks on a 1/8MOA click scope)
200yrd crosshair = 200yrds zero
300yrd = 325yrds - 2.0MOA
400yrd = 450yrds - 4.4MOA
500yrd = 565yrds - 7.1MOA
600yrd = 685yrds - 10.1MOA
700yrd = 800yrds - 13.3MOA
800yrd = 910yrds - 17.0MOA

To hit 1000 yards as you sit now, and providing you're zero'd at 200yrds as the scope is meant to do, dial up 3 minutes and hold on your 800 yard stadia and you should be on steel at a grand.

If you want help getting there from here please let me know. It's only math and I'm happy to help.

 

[Newbweatherby]

1, I would absolutely NOT use a 20MOA base unless you only have 6-7MOA of up left in the turrets right now with a 100yrd zero. That's bad advice IMO as it ignores the fact that the total adjustment of the scope is 26MOA. If you're centered right now then you'll be 7MOA high at 100 yrds and not be able to fix that. That makes for a forced 500yrd zero.

Regarding Sniper101, Rex's focus is purely on practical uses of a rifle against animate targets (including targets that might shoot back) under field conditions. For that a FFP tactical scope is optimal because his use case suggests that ranging with the reticle is going to be part of the activity. That said, he discusses both pretty extensively. Enough that most questions are answered if you pay attention. I'll go further for you, try to make you life easy.

Your Minox is NOT going to be a problem. You can really easily dial in a few minutes in the mounting system. Before I tell you exactly how I need to know where you're at in the scope at your zero... how much up you have left. Once I have that data I can tell you exactly what you need. My hunch is that you'll be right off the bat but that a set of Burris Signature Series 30mm Zee rings and a set of their eccentric inserts in 0MOA and 10MOA might stretch you out to 1500yrds or more between reticle and turrets. We should be able to get you set up so you can dial to 1000yrds or slightly more and still have a 200yrd zero with ~1" above line of sight at 100yrds.

From my initial checking and some ballpark-y ballistics numbers I did for you it looks like you're set up as follows on your BDC reticle (BDC indication = Actual range - MOA value). Numbers below are for a 185gn low drag bullet at 3250fps:
100yrd dial .75MOA down (6 clicks on a 1/8MOA click scope)
200yrd crosshair = 200yrds zero
300yrd = 325yrds - 2.0MOA
400yrd = 450yrds - 4.4MOA
500yrd = 565yrds - 7.1MOA
600yrd = 685yrds - 10.1MOA
700yrd = 800yrds - 13.3MOA
800yrd = 910yrds - 17.0MOA

To hit 1000 yards as you sit now, and providing you're zero'd at 200yrds as the scope is meant to do, dial up 3 minutes and hold on your 800 yard stadia and you should be on steel at a grand.

If you want help getting there from here please let me know. It's only math and I'm happy to help.

t
thank you guys for all the useful info

 

[yobuck]

Well lots of good information, but again just go shoot and figure it out from there. You either will, or you wont have enough adjustment in your scope to shoot as far as you might like. Shooting will let you know that quickly. As recently as about 20 years ago there were no factory made tapered scope bases, or scope ring inserts either.
But lots of guys were very successfully killing deer at very long ranges without them. My son still has a few layers of soda can shim material under the rear base on his 700 actioned 7x300 Wby with an old 6.5x20 leupold on it, and so do some others i know.
Much is to do about mind over matter, and if you don't mind then it don't matter much as long as it works well.
I would suggest you give thought to your shooting position.
From your comments, I'm assuming your of advancing age and not in the best of condition. Don't make things any harder on yourself than is necessary in order to do this. If you would like to play the sniper game that's fine, but if not that's fine also.
If you have a good portable bench by all means use it. If not you can create one easily with a couple carpenter saw horses and a pc of plywood on top of them. You will find a bipod will bounce off the bench some as you shoot. For that reason a few pc of 2x6 cutoffs with a sandbag on top might be better. In either case a rear rabbit ear bag is advisable. If you have a folding work station, that might be utilized also. Do a dry run at home to make sure things work ok.
Virtually all PA long range hunting is done with the aid of some type of bench or a very good tripod system. That regardless of the age or condition of the shooter. Terrain conditions are the reason primarily,
but fact is older hunters like me simply couldn't do it any other way.
The only ones needing to be impressed are yourself, and the thing your shooting at.

 

[BallisticsGuy]

Well lots of good information, but again just go shoot and figure it out from there...

^^^ Advice I would suggest be simply dismissed. Why? Simple. We can know precisely where the scope is now without firing a shot.

We already know precisely where it needs to be to enable kilometer hits. Thus we can know precisely what is required to enable that from the exact situation he's currently in without firing a shot. This send one and correct goop is nothing but an admission that someone doesn't know and/or is unwilling to do a little addition to get the answer. The answer is, tell us how the scope sits in its mechanical range (exactly how much up is left from your zero) now and then we do the addition for you and figure out what you need in hardware if anything.

If you'd like a hasty ballistics chart with your data and reticle and holdovers and such on it, ping me with a PM and I'll help you out. It's free so you might as well just take me up on it.

 

[yobuck]

^^^ Advice I would suggest be simply dismissed. Why? Simple. We can know precisely where the scope is now without firing a shot.

We already know precisely where it needs to be to enable kilometer hits. Thus we can know precisely what is required to enable that from the exact situation he's currently in without firing a shot. This send one and correct goop is nothing but an admission that someone doesn't know and/or is unwilling to do a little addition to get the answer. The answer is, tell us how the scope sits in its mechanical range (exactly how much up is left from your zero) now and then we do the addition for you and figure out what you need in hardware if anything.

If you'd like a hasty ballistics chart with your data and reticle and holdovers and such on it, ping me with a PM and I'll help you out. It's free so you might as well just take me up on it.

Well i don't believe i encouraged him to just go shoot without having
an elevation chart along, but if i did, then my bad for not advising that.
As for charts, the first one i had was given to me many years ago by a guy who was using a 6.5x300 wby for l/r deer hunting.
I didn't have a 6.5x300 wby, i had a 7x300 wby, but he said don't worry about it because it will be pretty close, and you can correct off that and make changes as you go. And he was right, it was pretty close, in fact close enough that i used it for a long time. Back then there were no places you could go and get a chart for a specific gun or load, so you took what information you could get and then tweeked it to suit. And fact is that's still a good approach.
Conditions are always changing, and even slight changes will have at least some impact on the information you have anyway.
And we haven't even opened the can yet on the biggest issue which is the wind.
The best thing a shooter can do is concentrate on seeing his hits. If he can do that, and he understands how to use a scope so that a miss is a hit on the next shot, he will be well on his way.
And he dosent need any particular type scope in order to do that, so long as it has a dial.
But at this point the guy is still sitting in his chair just thinking about it.
My advise has been to take what equiptment and knowledge he now has and go get started. He will make mistakes, will learn how to correct them, and also form his own opinions, just like all the rest of us.

 

[Newbweatherby]

actually I appreciate all the input ,and i think i may have over complicated it in my own mind.Mybson and i did some informal shooting yesterday and he reminded me that my Bushnell arc1300 had elevation for our loads in MOA mils and inches .So would this be accurate enough?

 

[yobuck]

Well in answer to your question, yes it would no doubt work, BUT.
I would question that you might have to enter some specific information first regarding your gun and location, etc etc.
Quite a few lazer rangefinders are now offering that option.
You can also go on line and visit any of the numerous sites offering that type service. Many shooters are now downloading a program into a suitable i phone, and then use that when dialing. Ive been using JBM for quite awhile, but there are others also. I simply have a printed chart for each gun that i keep with me.
The site selected will ask questions, such as the air temp, which i simply average based on the time of year i hunt.
Also elevation above sea level, which again i average for my area. Scope height above the bore which can be found by measuring the distance from the gas port to the center of the scope ring. Barametric pressure can also be averaged. Velocity is as a rule known, as is the bc of the bullet being used. By now you get the drift of what will be asked of you in order to get the information you want from the server. My advise to you is at least for now, get the best you can as for a chart on your own, because even that is advancing your education. You might be a technifreak by nature and
will never be happy for long with anything unless its the very latest.
And that's fine, and might even be the best, depending on what your doing. But for l/r hunting, and especially for whitetail deer, precise data while desirable, as a rule isn't all that important.
Where i hunt, tree branches can be a bigger issue than less than perfect up to the minit data for dialing. Get lead in the air and keep it there till its over, and you will be far more successful than the perfectionist will.

 

[Newbweatherby]

Second focal plane is fine. My nsx is second focal plane and it rocks my socks.

Looks like that Minox scope only has 26 moa total internal adjustment. +13 -13. Your max range will be limited no doubt about it, because the sub tensions will change poi at range with magnification change.

This means dialing is your only option in a hunting situation unless you are always at max power when shooting. You may find a combination of max power and sighting off a subtention along wth dialing gets the precision you need for shots to 800+, but my gut tells me you will probably find your practical limit somewhere at 600ish. If you replace those rings with Burris signature z rings you may gain additional internal adjustment up, and possibly a little left right if you had issues centering the sight in.

 

[Newbweatherby]

I do have the Leoupold 20 moa mark 4 rail which should help and at 550 i am eight using the 3rd substentions

 

[tbrice23]

[QUOTE="yobuck, post: 1395834, member: My son still has a few layers of soda can shim material under the rear base on his 700 actioned 7x300 Wby [/QUOTE]

This is a horrible idea, I do not ever recommend anyone do this....ever.

 

[yobuck]

[QUOTE="yobuck, post: 1395834, member: My son still has a few layers of soda can shim material under the rear base on his 700 actioned 7x300 Wby

This is a horrible idea, I do not ever recommend anyone do this....ever.[/QUOTE]

Try if you can to understand that 25 years or so ago
many of the things you use today simply didn't exist, and that includes most of the scopes.
Even with excellent long range cartridges like a
7 STW, or a 7x300 WBY you probably couldn't dial
past about 1000 yds. So that left either shimming or
having someone machine the scope base.
Shimming was easy so most guys just did that, and guess what?
Regardless of what you think it actually worked just fine.

 

[BallisticsGuy]

Try if you can to understand that 25 years or so ago
many of the things you use today simply didn't exist, and that includes most of the scopes.
Even with excellent long range cartridges like a
7 STW, or a 7x300 WBY you probably couldn't dial
past about 1000 yds. So that left either shimming or
having someone machine the scope base.
Shimming was easy so most guys just did that, and guess what?
Regardless of what you think it actually worked just fine.

Maybe with a 1 piece base I could get behind that idea. It's otherwise as has been stated and regardless of anyone's hurt feelings a bad idea.

With 2-piece bases done how you're describing, just some shims under the back base, you're asking for a bent main tube and to cause the scope to act funny under adjustments. Just because it worked for some people that didn't know any better doesn't mean it's a good idea or one anyone that knows what they're talking about should advocate. Nobody's insulting anyone for having done the shimming thing. They're saying, "'Hey! That's actually a seriously bad idea!' and 'People sure did silly things in the past.' and 'We have better solutions nowadays so how about using the better and inexpensive solution and not breaking your toys.'"

Folks get so bent out of shape to find out they're doing it wrong. How about admit to one's self that you did it wrong, marvel at the success you managed despite that and then, decide to do it right.