Purists Please - Final Scoping Procedures Please

FISMA

Lads,
Would like to hear what the purists have to say about the final tuning of scopes at the range in order to minimize error and maximize range.

I have setup the scope, leveled, torqued, lapped, and all.

I will be at the range next week. We have nice strong sturdy tables on which I will place my vice. The gun will be leveled.

From here on in, what's your procedure? Purists, have your say, but please explain why. I am especially interested in how those that in the zone with 600-800yard shots are setting up.

I am thinking that I should:

(1) put the laser in the bore
(2) setup target 100ya downrange and center on the red dot
(3) fire three shots (my 700 likes 180gr) should be tight
(4) have scope follow the holes

Holes should be under the red dot. Bullets drop, LASERs will not drop (no comments on curvature of space time please :-)

So the bullet holes should be under the red dot. Have you ever tried to pitch the barrel up slightly to get (both a near zero and far zero point) the bullets to impact the red dot?

We are talking some decent speeds, round wise. I expect a muzzle velocity of 2700 fps and 2023fps at 200ya.

With these numbers, bullet drop should only be about 2.57inches, unless the auld algebra went awry - please see below.

In practice, I rarely see shooters: (a) ensure the rifle is leveled AND (b) level the target on the same plane as the barrel.

So,
(1) should I make the holes follow the dot?
(2) should I make the scope follow the holes?

FWIW, the sub 400yards shots are fine. The 600 - eh. The 800ya +, disappointing.

Will be heading out to a cousin in the states in PA. He says there's a thousand yard range - looking forward to getting on paper.:pac:

If it is me, so be it, I just need to rule out as many errors as possible.

So please advise, the more specific, the better.

************Warning Mathematical Content Follows *************
v = muzzle velocity = 2600.0fps (take 100fps off for friction at 100ya) = 792.48m/s

distance = 100.0 yards = 91.44m

since speed=dist/time

=> t = d/v

t = 91.44m/792.48m/s = 0.11538s

It is safe to say that the bullet is accelerating downward at a constant rate so the good old kinematic equations can be used.

drop = yf - yi = voy(t) + 1/2a(t)^2

where
yi = the initial position of the round - at the height of the muzzle =0m
yf = the final position of the bullet - vertically, not horizontal
voy = the initial velocity in the vertical direction (there is none)
t = time of flight
a = g = +9.80m/s^2 - standard average - should measure it in the bog!:cool:
note: + is down
yf - yi = the bullet's displacement - the drop

since voy = 0m/s

drop = 0.5(g)(t)^2 = 0.5(9.80m/s^2)(0.11538s)^2 = 6.52cm = 2.57in

Does 2.57 inches sound like a lot of drop? This is a considerably hot round. Considering that my muzzle velocity is 2700fps, I did not take off much for friction in the first 100ya. Thus, with a speed that may be too much, on average, the drop would be even more.

Thanks to anyone willing to check my math. Love the Physics, always hated the Algebra.:(

clivej

I'm no expert and this is from what I'v read or the DVD's I'v looked at so just a couple of points here.

1. Measure the target distance correctly. Say 200y.
2. Chrony your ammo at both the muzzel and target if you want a true speed. Using a chrony is the only way to get your REAL MV, average, Hi, Lo, ES.
3. Move your target back to known distances. Say 300y, 400y, 500y, 600y, 700y...............etc. Now measure bullet drop at each distance.
4. Put everything into a balistics program like Exbal so that the bullet drops match your findings on the different targets, alter BC or MV in Exbal so they all match.
5. Now you have an accurate drop chart for those bullets over any range.
6. Remember to note the tempreture and pressure of the weather on the day you do this and enter this into Exbal.

Cass

You lost me at the maths class.

A few things first. You are using a Remmy 700? I presume from the 180 gr bullets its a .308 cal. What is the twist rate of your rifle. If its a 1:9 then the 180s will perform well. If its the usual 1:12 they will not. What brand and type of ammo. ie. is it HPS, Lapua, etc. Are they hunting rounds, targets rounds what? Whats the BC of the round, the sectional density? Is that MV estimated or chrono'd? What length is the barrel? Height of your scope of the receiver.

If you can answer most of these you will get a better answer than with the math.

sfakiaman

Quote So the bullet holes should be under the red dot. Have you ever tried to pitch the barrel up slightly to get (both a near zero and far zero point) the bullets to impact the red dot? Quote.

Given that the scope is above the axis of the barrel, then the bullet has to pass through the line of sight twice, once on the way up and again on the way down. A ballistics programme will let you calculate that for your load, scope hight etc. MNSCI have targets for zeroing for long range on the 25 yd pistol range, never used them myself but would be worth a try. The math, while interesting, could wreak your head before you get on paper. As an old friend used to say 'seeings believing but feelings the gods honest truth .

BELOWaverageIQ

I love it when guys use mathematics to justify their love of things that go *BANG* :D

FISMA

Thanks for the replies lads.

clivej wrote: »

I'm no expert and this is from what I'v read or the DVD's I'v looked at so just a couple of points here.

Clive, It sounds like you are an expert - that's pretty much what I want to do! I just do not have the luxury of trial and error at those distances. My max practice shots are done at 300ya.

Ez, the way I have done it for years is basically the way you have described in other posts, such as looking down the bore. It has performed spot on, within 400 yards, iron sights or glass. However, now, reaching out to 800 yards, things are not going well.

sfakiaman wrote: »

Given that the scope is above the axis of the barrel, then the bullet has to pass through the line of sight twice, once on the way up and again on the way down.

I think this may be the source of confusion for me. Currently, my round is only dropping. The way I set it up, the barrel is horizontal. Thus, when the round clears the barrel, it is for all practical purposes, accelerating in two directions: downwards at free fall (9.80m/s^2) and it is slowing down in a horizontal direction.

This is where I am confused. Rarely have I ever seen anyone attempt to get their rifle barrel and target in a horizontal plane.

Perhaps, it makes no difference whatsoever. But at the field when sighting in, your target could be a bit lower or higher, than the plane of a level barrel. I am wondering what, if any, this has on long range shots. It seems to make good sense that a level barrel should shoot at a target that is centered on the same plane as the barrel.

Do ye lads level the barrel at the range before final sighting in? If there's anyone shooting out to 800ya, please advise.

Again, a trial and error method would be nice. But I do not have the luxury of such an area for practice.

Most people I see at the range do not level barrels, instead, angle up. This is fine and grand on the 100ya, but at 800ya?

I am still confused.

Hasn't the scope's manufacturer has gone to great lengths to determine a reticle that will consider a horizontal shot from a horizontal barrel at 100, correct?

Isn't this why we always shoot low, uphill or down? The reticle's scale is calibrated for horizontal shots, true. But was it designed to have the rifle horizontal while taking those shots on a horizontal?

Or am I wrong? Is the level of the rifle irrelevant as long as the scope is initially placed parallel to the barrel.

I am not saying that the rifle has to always be horizontal. Perhaps, sight in at 100ya with a horizontal rifle and the rest assume a pitch, especially the 600mark.

At 100 ya, if a bullet drops 2.5", the scope's line of sight need only be dropped 1/1440th of a degree in order to hit the bullet hole. That's certainly something the scope could dial out of a level barrel.

I have gone to great lengths to: (1) get my scope to almost sit on the barrel,(2) return half a doze rings that were too high, (3) lap rings, (4) level rifle, and (5) level scope. The last thing I want to do is cause variance due to my own ignorance.



Also Ez, would the specifics help? It is my opinion that the problem is not one of the variables that you questioned. If you still believe it to be so, please advise and I'll make a list.

Thanks again.

I think I am going to email Leupold or Burris.

clivej

Forget the math and get back to basics.
Your barrel is in a vice on the horizontal and the scope is parallel to the bore sitting on top. you fire off a couple of rounds and they drop 5" to the target at 200y. So now you dial in the correct amount MOA of up to get the retical on the point of impact (POI)

So the scope is still paralell but the point of aim (POA) is now pointing down to where the POI is.
OR you could fit a scope rail that has this downward built into it so the complete scope is now pointing down say a 10 MOA rail. What you see through the scope is a straight line but the barrel is for all intents now pointing up slightly and the bullet will cross the sight line and then fall back to the POI.

The bullet will always fall once it leaves the barrel so you dial in up (or hold over the target) to the retical to get you on target, the futher out the target the more up you dial in to get you back on to POI. Agian this is why long range target shooters use 10 or 20 MOA rails so it will give them more clicks of up, cos the actual scope is already pointing down.


.223 55gr bullet zeroed at 200y. It shows the sight line at 0 and the barrel 1 1/2" below the sight line but pointing slightly up.
The bullet will cross the sight line going up, at about 30yards, and then be on bull target on the way down at 200yards.

Cass

I'm after reading through this 3 or 4 times and i'm that confused with all the numbers and formulae being floated around that i've lost track of what the OP is actually looking for.

A question that will simplify and hopefully clarify it for me. Do you want to get your zeros for the different distances in multiples of 100yds from 100 yards out to 800/1,000 yards. If so there are 2 options.

Tell me the make,model, twist rate, bullet weight and barrel length of your rifle along with the click value of your scope and i'll give you the actual moa to within a minute. Not by using some BC calculator, but from experience.
If you doubt this or my ability to do this then i'll make a one time offer to meet you someday on the range and give me an hour an i'll have you shooting out to 1,000 yards.

clivej wrote:

1. Measure the target distance correctly. Say 200y.
2. Chrony your ammo at both the muzzel and target if you want a true speed. Using a chrony is the only way to get your REAL MV, average, Hi, Lo, ES.
3. Move your target back to known distances. Say 300y, 400y, 500y, 600y, 700y...............etc. Now measure bullet drop at each distance.
4. Put everything into a balistics program like Exbal so that the bullet drops match your findings on the different targets, alter BC or MV in Exbal so they all match.
5. Now you have an accurate drop chart for those bullets over any range.
6. Remember to note the tempreture and pressure of the weather on the day you do this and enter this into Exbal.

I don't get this. Why after going out the distances would you then use a ballistics calculator, and on top of that alter the readings to make them match your actual results. Its either one or the other not both. So to use clivej's list and alter it a little ;

1. Measure the target distance correctly. Say 100y.
2. Chrony your ammo at both the muzzel and target if you want a true speed. Using a chrony is the only way to get your REAL MV, average, Hi, Lo, ES.
3. Put everything into a balistics program like Exbal to find your drops.
4. Now you have an accurate drop chart for those bullets over any range. Tweak for the actual MOA to adjust for daily conditions at the distances.

OR :

1. Measure the target distance correctly. Say 100y
2. Move your target back to known distances. 200y, 300y, 400y, 500y, 600y, 700y...............etc. Now measure bullet drop at each distance. Adjust your scope the necessary MOA and record adjustments. Keep record of the final actual adjustment for each given distance.

There is no need to use a BC calculator when you are actually firing the distances as this will give you the necessary MOA. A BC calculator is primarily to aid you in getting as close as possible (if not dead on) to the "bullseye" without having to fire all the necessary bullets to find out.

shanmoll308

Long range varminting EZ, those eg. 468 yard! rabbits need precision come-up's bud..

Shanmoll308

Cass

Ah, got it now.

clivej

ezridax wrote: »

Ah, got it now.

The reason to alter the MV or BC to match the actual drop is that the BC given by the makers is a little optimistic to say the least. The only way to get a true bullet drop at a set distance is when testing the ammo in the field.
And then your drop chart will have the correct increments for the rabbit at 725 yards. :rolleyes:

Cass

clivej wrote: »

The reason to alter the MV or BC to match the actual drop is that the BC given by the makers is a little optimistic to say the least.

clivej wrote:

Chrony your ammo at both the muzzle and target............

You can see why i asked. If your are chronographing the ammo then the manufacturers estimate is irrelevant. You have a true MV to insert into the BC calculator. Along with the other exact information you will get the necessary drop.

I only asked a question and it took Shanmoll308 to come on and tell me its varminting not target shooting where the ranges will not be in 100 yard intervals. So the ":rolleyes:" is unnecessary.

tomcat220t

Most long range bullets are boat tail rather than flatbased so G7 b/c values would give more accurate figures ,imo.

clivej

ezridax wrote: »

You can see why i asked. If your are chronographing the ammo then the manufacturers estimate is irrelevant. You have a true MV to insert into the BC calculator. Along with the other exact information you will get the necessary drop.

I only asked a question and it took Shanmoll308 to come on and tell me its varminting not target shooting where the ranges will not be in 100 yard intervals. So the ":rolleyes:" is unnecessary.

:rolleyes: ops did I step on your corns???? :rolleyes:

Tackleberrywho

ezridax wrote: »

You can see why i asked. If your are chronographing the ammo then the manufacturers estimate is irrelevant. You have a true MV to insert into the BC calculator. Along with the other exact information you will get the necessary drop.

I only asked a question and it took Shanmoll308 to come on and tell me its varminting not target shooting where the ranges will not be in 100 yard intervals. So the ":rolleyes:" is unnecessary.

This Shamol guy seems to know his stuff, I must go varminting with him some day

dCorbus

Be warned, lads, that shanmoll308 fella really doesn't know what he's talking about! Couldn't shoot a decent group if he tried!:D:rolleyes::rolleyes::rolleyes:

(And neither does that ezripants fella either!)

Tackleberrywho

dCorbus wrote: »

Be warned, lads, that shanmoll308 fella doesn't know what he's talking about! Couldn't shoot a decent group if he tried!:D:rolleyes::rolleyes::rolleyes:

(And neither does that ezripants fella either!)

Ah now, we all know Shamol is something special behind a rifle

dCorbus

He's fecking "special" all right!:D:D:D:rolleyes:

Cass

clivej wrote: »

:rolleyes: ops did I step on your corns???? :rolleyes:

Yeah. I'm all upset. Ya big ............. corn ............... stepper................ on-ner.................. person.

Tackleberrywho wrote: »

This Shamol guy seems to know his stuff........

Now this is what ya use ":rolleyes:" for.

dCorbus wrote: »

(And neither does that ezripants fella either!)

Ahem, MR Ezripants.

dCorbus wrote: »

He's fecking "special" all right!:D:D:D:rolleyes:

So many ways to slag, must............ resist ...........

Tackleberrywho

Ezridax and dC, do I detect a tone of Jealousy of Shamol ??

He gave a friend of mine varminting lessons, and now that guy is very competent taking foxes out to serious distances, I might ask Shamol for same !

Cass

Tackleberrywho wrote: »

Ezridax and dC, do I detect a tone of Jealousy of Shamol ??
!

Serious hat on now.

No, not jealousy. I suppose respect would be a more apt word.

The chap knows his s**t. No question. I shoot with him every week, and simply put he is the best shot i've seen - consistantly.

I have brought my rifle up to the best spec i can, and i know its well capable of doing more than i can, but thats okay. Between himself and another lad i'm picking up stuff as i go. I spent a half hour yesterday after the first F-Class shoot talking with D.C. and he gave me some good and effective pointers that i'm going to give a bash with next time i'm over.

Occassionally, going simplier can be more effective ( shooter dependant) than going for the more complicated/advanced route. Personal observation.

Tackleberrywho

Reminds me of how I aim at bunnies over 300 yards.

I could click, but instead I use the rangefinding reticle, it just works for me.

How ever I am more a Hoorist than a purist.
I was looking at a one piece NF base/ring that could simplify shooting for me.
Base mounts directly to remmy
http://action-concepts.com/items/riflescopes/nightforce/rings~mounts/nightforce-direct-mount-nf10sa120dm-detail.htm

It could simplify initial set up

shanmoll308

Thank's guy's but let me out of this one...and Tack, it's Shanmoll308 :rolleyes:!!:D

Shanmoll308.

dCorbus

Ezridax and dC, do I detect a tone of Jealousy of Shamol ??

Not at all!

It's not jealousy on my part - Don't get me wrong - It's more akin to a warm fuzzy feeling of respect and admiration!:rolleyes::D

But seriously and all joking aside - the lad is one of the best - consistently - and he's that way, coz he practices and practices and practices - with a very big dollop of natural talent on top of all that practice.

I spent a half hour yesterday after the first F-Class shoot talking with D.C. and he gave me some good and effective pointers that i'm going to give a bash with next time i'm over.

Ez, I can only presume you mean you got "good and effective pointers" from D.C., rather than dC! Because it would be very much a case of one of these:



flying over one of these:



before dC is able to provide any semblance of "good and effective pointers" to such fellow shooters as your goodself!

I was looking at a one piece NF base/ring that could simplify shooting for me.

Question, coz I is confussed: How is a one-piece scope-base going to simplify your shooting? It may very well simplify your initial set-up and equipment, but not your shooting per se. Or am I missing something?

Tackleberrywho

Shanmoll308, I humbly apologise If I only knew who you were I might ask you for some varminting tips

dC
I meant setting up rifle scope etc, as this thread used to be about Purists and simplifying things.
The less nuts and bolted joints the less parts to align in setting up scope.

I would like to leave a situation where I could easily swap over NF scopes from one remmy to another. Both rifles are short action, and both scopes have same demensions just different mags,

I have seen a few Custom jobs recently that mont's and rings were just one piece, seems a good idea if one likes to take scopes off from time to time.

however it was only a passing thought, as I was considering lowering the scope on my .308, so as i was looking for mounts I came across the previously mentioned site