New to long range shooting need advice for 308 come ups

[Little Creek]

I have an unfired Savage 10 FLCP-K in 308. By 2/11 I will have a NF SHV 5-20x56 with MOAR illuminated reticle, a 20 MOA base, and 1" high rings. My home range has 100yards and 200 yards. I will be shooting 168gr Match ammo. At what distance should I zero? From that zero, what would the suggested "come ups" be for 400, 500,etc yards out to 1000 yards. There is a 1000 yard range within driving distance. I just want to get some idea of where to start. BTW, what are your suggestions as to breaking in this barrel?

[markm]

If you plan to do some 1000k shooting. Just start and stick with 175gr ammo. Zero at 100. 500 yard come up should be about 3.5 mils.

[BOOSTjunkie]

175 grain SMK HPBT is the industry standard for 308 pills pushing around 2700 fps should be the ticket for you

you can touch 1000 at just around 10 and a half mils

500 is about 3.5

600 is about a hair over 4

800 is about 7

100 is your zero

Good to go?

[Failure2Stop]

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
http://appliedballisticsllc.com/ballistics/

Both have a good library of projectiles, you just need to get your MV, optic centerline above bore, and general environmentals (you can run standard corrected at your altitude and be close).

Barrel break-in: many more opinions than hard data on this. I tend to stay away from the voodoo and stick with shooting. Cleaning carbon is more important than removing all copper. During zeroing, push a wet patch followed by a few dry patches between groups for the first 4 or five groups and watch for group shift. Take meticulous notes and pictures of your groups. Hard-core precision folks will likely disagree with me.

Agreed with 175s for work past 600.

[BOOSTjunkie]

there is much voodoo involved with breaking in a barrel and cleaning it as far as a precision rig is concerned... you could try shooting it?

[Little Creek]

If you plan to do some 1000k shooting. Just start and stick with 175gr ammo. Zero at 100. 500 yard come up should be about 3.5 mils.

Does 1 MOA = 3.6 mils? If so that would make the MOA come up for 500 yard about 10 MOA with a 175 gr Match bullet. Is that in the ball park?

[Little Creek]

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
http://appliedballisticsllc.com/ballistics/

Both have a good library of projectiles, you just need to get your MV, optic centerline above bore, and general environmentals (you can run standard corrected at your altitude and be close).

Barrel break-in: many more opinions than hard data on this. I tend to stay away from the voodoo and stick with shooting. Cleaning carbon is more important than removing all copper. During zeroing, push a wet patch followed by a few dry patches between groups for the first 4 or five groups and watch for group shift. Take meticulous notes and pictures of your groups. Hard-core precision folks will likely disagree with me.

Agreed with 175s for work past 600.

Many thanks for those links and the advice on barrel break-in.

[Failure2Stop]

Does 1 MOA = 3.6 mils? If so that would make the MOA come up for 500 yard about 10 MOA with a 175 gr Match bullet. Is that in the ball park?
1 mil is 3.6 inches at 100 yards

[markm]

Does 1 MOA = 3.6 mils? If so that would make the MOA come up for 500 yard about 10 MOA with a 175 gr Match bullet. Is that in the ball park?

3.5 = 11.81 MOA, to be exact.

[Ming_the_Merciless]

Does 1 MOA = 3.6 mils? If so that would make the MOA come up for 500 yard about 10 MOA with a 175 gr Match bullet. Is that in the ball park?
1 mil is 3.6 inches at 100 yards

Jack is right, here's the math:
http://i1061.photobucket.com/albums/t465/Ming_the_Merciless86/1_mil_to_inches_zps75c868de.png

It's a common mistake to think that 1 mil equals 3.4" at hundred, oppose to 3.6", because 1 mil equals 3.4 MOA.

Another common mistake when folks are making conversion is 1 MOA equals 1" at 100 yards (but in reality is 1.0472" ), discounting the 47 thousandths, is close enough for government work. Even at 1000 yards, you're looking at an error of half an inch (0.47"), so practically negligible.

http://i1061.photobucket.com/albums/t465/Ming_the_Merciless86/1MOA_at_100yards_zps3ab98a40.png


3.5 = 11.81 MOA, to be exact.

Negative, 3.5 mils = 12.03 MOA:
http://i1061.photobucket.com/albums/t465/Ming_the_Merciless86/35Mils_to_MOA_zpsa9e97ca0.png

[markm]

Negative, 3.5 mils = 12.03 MOA:

I must have googled the wrong conversion site. ;)

You should see how messed up it gets if an MOA shooter comes out with us.

[Failure2Stop]

Ok, just noticed that you're using the MOAR reticle and are tied to MOA.
I don't know if NF uses true MOA or SMOA for their reticle and/or adjustment.
This is not a big deal for most, but depending on your actual range and target size, it might be.

Here's why:
The difference between MOA and Inches ("Shooters MOA") at 1000 yards is about 17":
-378.3 Inches / -36.1 MOA.

[Failure2Stop]

I must have googled the wrong conversion site. ;)

You should see how messed up it gets if an MOA shooter comes out with us.

I refuse to shoot with MOA people.




Mostly kidding.

[Ming_the_Merciless]

I must have googled the wrong conversion site. ;)

You should see how messed up it gets if an MOA shooter comes out with us.

I refuse to shoot with MOA people.




Mostly kidding.

Yeah, tell me about it. I hate the delay spotting for MOA shooters, converting from mils to MOAs. If I don't have a calculator on hand, it helps to have my hold over chart in both mils and MOA, and I use that for reference for the MOA shooter, but by the time I make the call, the wind most definitely died down and now I'm struggling to make a new call before it changes again.


Ok, just noticed that you're using the MOAR reticle and are tied to MOA.
I don't know if NF uses true MOA or SMOA for their reticle and/or adjustment.
This is not a big deal for most, but depending on your actual range and target size, it might be.

Here's why:
The difference between MOA and Inches ("Shooters MOA") at 1000 yards is about 17":
-378.3 Inches / -36.1 MOA.

Jack's correct again. Here's the supporting math for those that want to follow through:

To derive what 1 SMOA is equal to (in terms of MOA):
http://i1061.photobucket.com/albums/t465/Ming_the_Merciless86/1SMOA_to_MOA_zps603caf00.png

So using the above example, bullet drop of 378.3" at 1000 yards:
http://i1061.photobucket.com/albums/t465/Ming_the_Merciless86/3783inch_at_1000yd_MOA_zpsfde0f3d0.png

A hold over of 36.12 MOA actually corresponds to 37.82 SMOA:
http://i1061.photobucket.com/albums/t465/Ming_the_Merciless86/3612MOA_to_SMOA_zps6bf0a872.png

If the shooter dials in 36.12 SMOA in error, not knowing they have turrets that correspond to 1" at 100 yards, oppose to 1.047" at 100 yards, then what is that error?
http://i1061.photobucket.com/albums/t465/Ming_the_Merciless86/3612SMOA_at_1000yd_Height_zpsd58a592a.png

We know our bullet drop is actually at 378.3", but the shooter's turret are IPHY (one inch per hundred yards), then the error is the difference, striking high approximately 17" as Jack said:
http://i1061.photobucket.com/albums/t465/Ming_the_Merciless86/SMOA_v_MOA_Difference_w_3783Drop_at_1000yd_zps4ac43522.png

[Pappabear]

I'm far to fkn dumb to convert to moa. It's most "hunting " scopes are MOA. It surprises me how proliferic they still are.

[skywalkrNCSU]

I have been researching scopes and figuring out what I want for my bolt gun for long distance shooting and I understand how most people use mils but moa just makes so much more sense to me. I feel like I could pick up a moa scope and be able to range and adjust my shots with just a little practice because I can think about how it works a lot easier doing the math in my head. I am a bit concerned about not getting a mil scope but I don't really shoot with others and I have a long long way to go before I would be doing anything like competition shooting.

I guess if I ever did shoot with mil guys I would just take a cheat sheet with a bunch of mil/moa conversions on it. I'm surprised there isn't some sort of slider tool that would do it for you (there might be and I just don't know about it).

[Failure2Stop]

I have been researching scopes and figuring out what I want for my bolt gun for long distance shooting and I understand how most people use mils but moa just makes so much more sense to me. I feel like I could pick up a moa scope and be able to range and adjust my shots with just a little practice because I can think about how it works a lot easier doing the math in my head. I am a bit concerned about not getting a mil scope but I don't really shoot with others and I have a long long way to go before I would be doing anything like competition shooting.

I guess if I ever did shoot with mil guys I would just take a cheat sheet with a bunch of mil/moa conversions on it. I'm surprised there isn't some sort of slider tool that would do it for you (there might be and I just don't know about it).

We didn't all stop shooting MOA based optics because they worked great.
I understand though, sometimes folks have to suffer through other's experience.
I do assure you though that following the MIL/MIL path will save you money on the front end.

One significant factor is that people think that because they think that they can visualize an inch that holds will be easier.
The issue with this is several-fold:
1: Determining length at distance is difficult, and you need an angular measurement anyway.
2: Most people can't accurately determine actual length at arms distance anyway.
3: Mil based holds are not tied to metric measurements, but are simply 10 (100, 1000) based measurements.
4: You will need to have someone teach you how to actually shoot at long range anyway, regardless of whether you have a shooting buddy or not. Virtually none of these folks shoot with MOA based optics.
4A: Long range shooting without a spotter is an exercise in frustration.

There are easy conversions for MIL to MOA, but you wouldn't use it for long anyway, since you will need a custom table for your gun and load anyway. Get a good ballistic calculator, even if just to make your cheat sheet.

[Hootiewho]

OP, depending on where you are at in GA you have tons of resources. Elberton gun club has 1000 yard day and night F'classish/field benchrest matches nearly monthly.

Chief O'Neil has a good match at Gunsite Hills. He is a very good dude, but very direct. Thick skin is needed, but the dude has a great heart if you get to know him. He will also teach you most of what you need to know.

Joe Harris runs Creekside range north of ATL. He also runs I think bi-monthly classes/matches and runs the Mammoth Sniper Challenge out of the excellent Legion Range in South GA. He is another solid dude. Hell Legion has a 400, 1000, & 2300 yard range. I took my AI AX338 there a while back and got hits to 2200 on a IDPA steel target.

Contact Thomas Woods at Accurate Ordnance as I believe he has a basic level training course at Legion coming up soon too.

You also have the Hardrock Match over in AL.

K&M has training and great matches down in the panhandle of FL.

I urge you to make it out to one of these places, or even ride up to Woody's Match in NC. You'll learn a ton in doing so as in general the long range competition community is much more open to help new shooters than any other branch I have seen. You can either shoot, or not; there is no BS'ing if you can hit a sub MOA target at 800 in a field expedient position under time. So in my experience, there is much less ego and gaming in general and usually just good dudes.

Also, don't think that dope is concrete. It will change some. Especially if you go shoot in FL one weekend and go up into the mountains the next.

[Hootiewho]

Also, sniper's hide use to have a great online training program, they may still; IDK. You have to pay a bit for access, but for a beginner, there is a wealth of info there.

[skywalkrNCSU]

We didn't all stop shooting MOA based optics because they worked great.
I understand though, sometimes folks have to suffer through other's experience.
I do assure you though that following the MIL/MIL path will save you money on the front end.

One significant factor is that people think that because they think that they can visualize an inch that holds will be easier.
The issue with this is several-fold:
1: Determining length at distance is difficult, and you need an angular measurement anyway.
2: Most people can't accurately determine actual length at arms distance anyway.
3: Mil based holds are not tied to metric measurements, but are simply 10 (100, 1000) based measurements.
4: You will need to have someone teach you how to actually shoot at long range anyway, regardless of whether you have a shooting buddy or not. Virtually none of these folks shoot with MOA based optics.
4A: Long range shooting without a spotter is an exercise in frustration.

There are easy conversions for MIL to MOA, but you wouldn't use it for long anyway, since you will need a custom table for your gun and load anyway. Get a good ballistic calculator, even if just to make your cheat sheet.

Interesting, thanks. I guess I need to still do more research and understand how the mil system works better. Good news is I haven't spent any money yet. Is there any advantage to mils vs mrad? The way I understand it the adjustments are the same so I am not too sure the difference.

[Failure2Stop]

Mils and MRad are the same.

[Eurodriver]

What happened to Mark's post? That was good info.

[Failure2Stop]

What happened to Mark's post? That was good info.
I'm not seeing a missing post...

I know that sounds rhetorical, but mods can see deleted posts, and I'm not seeing any indication of a removed post...

[Eurodriver]

Right before you posted Mark5pt56 had a very good chart listing the differences of MOA and mils out to 1000.

Even included a nice quote about "Windage is science at the muzzle, art down range"

Am I losing my mind?? Did I read that in another thread?

[mark5pt56]

I hit the wrong dang button.:(
All great info of course. You have to decide how you want to think, in minutes or mils. We tend to stay with what we know and that's minutes. Mils is easier to work with as explained, just be sure that the turrets and reticle match, otherwise you are trying to think in two units. This is important when spotting whether you are on your own or with a buddy, a buddy is better. For come ups, you have theory from charts and calculators but hard data from your gun and ammo along with various environmentals are better. The JBM one is great and I have used to to great success before. Phone apps are out there and prepublished ones, three that come to mind are the FDAC (field density altitude charts) the ones from Impact(various calibers) and Ballistacards. The two big things you need are velocity and Density Altitude (DA) others factors are in play as well like bullet data (length/coefficient/weight) When using JBM, they have the library and it's just a form to fill out. Physical altitude, temp range are inputs for the DA calculations. You will notice humidity is not one, that myth has carried over for so long. DA comes from physical altitude, pressure and temp, it's important to use this as that's what your bullet is "travelling" through. It matters, just see one extreme to the other and the effects are generally around the 5-600+ mark.
Anyhow most of the premade charts will get you there, you may need to tweak things a tad. I know on the JBM, I got a first round hit with a 300wm using Blackhills 190 grain at 1200 on a 12"x12" plate, they work.
There are so many variable to consider, you have to read and learn, shoot with others, listen, etc. You never stop learning it.
If you really want a good read, pick up Bryan Litz' books.

This is one chart I made for a .308 load, it's not pasting here aligned. It's on a theory 2600 fps,175smk DA at -2000, 0, +1000, +3000 and wind at 5 mph full value and corrections in mils, follow distance left to right, will be in moa and mils at each DA, then 5 mph wind correction(wind is at 0DA) NOTE-If you have to make these where you live/shoot as the DA is important. I'm in SE Va. so if you are in Colorado, you need a different set.


.308 175 @ 2600 W @ 0DA
-2000 0 5MPH
MOA MIL MOA MIL
100 .1
150 .8 .2 .8 .2 .2
200 2.0 .6 2.0 .6 .2
250 3.4 1.0 3.4 1.0 .3
300 4.9 1.4 4.9 1.4 .3
350 6.6 1.9 6.5 1.9 .4
400 8.4 2.4 8.3 2.4 .5
450 10.3 3.0 10.1 2.9 .5
500 12.3 3.6 12.1 3.5 .6
550 14.5 4.2 14.2 4.1 .7
600 16.8 4.9 16.5 4.8 .8
650 19.3 5.6 18.9 5.5 .8
700 22.0 6.4 21.4 6.2 .9
750 24.8 7.2 24.1 7.0 1.0
800 27.9 8.1 27.1 7.9 1.1
850 31.2 9.1 30.2 8.8 1.2
900 34.7 10.1 33.5 9.8 1.3
950 38.6 11.2 37.2 10.8 1.4
1000 42.7 12.2 41.0 11.9 1.6

.308 175 @ 2600 W @ 0DA
+1000 +3000 5MPH
MOA MIL MOA MIL
100 .1
150 .8 .2 .8 .2 .2
200 2.0 .6 2.0 .6 .2
250 3.4 1.0 3.3 1.0 .3
300 4.9 1.4 4.8 1.4 .3
350 6.5 1.9 6.4 1.9 .4
400 8.2 2.4 8.1 2.4 .5
450 10.0 2.9 9.9 2.9 .5
500 12.0 3.5 11.8 3.4 .6
550 14.1 4.1 13.8 4.0 .7
600 16.3 4.7 16.0 4.6 .8
650 18.6 5.4 18.2 5.3 .8
700 21.1 6.2 20.7 6.0 .9
750 23.8 6.9 23.2 6.8 1.0
800 26.7 7.8 25.9 7.5 1.1
850 29.7 8.6 28.9 8.4 1.2
900 33.0 9.6 32.0 9.3 1.3
950 36.5 10.6 35.3 10.3 1.4
1000 40.3 11.7 38.8 11.3 1.6

[mark5pt56]

Note the difference at 1000 yards, from -2000DA to +3000 DA. So if you last shot when it's cold, at sea level where I'm from and go out on a hot summer day for the 1k match-prepare to miss if you don't know it matters. Your .9 mils off-that's 3 feet +/-


THE CONFUSION OF HOW MANY INCHES A MIL IS AT 100 COMES FROM REFERENCING TWO DIFFERENT THINGS-MOA AND INCHES, SEE BELOW. It's common to use the 3.5 for "field work" meaning in your head on the fly

some info, something I made
Minutes of Angle are an angular measurement equal to*1⁄60*of one*degree.
There are 360 degrees in a circle, and each degree is composed of 60 minutes (60’).
Therefore, there are 360 (degrees) x 60 (minutes) = 21,600 minutes in a circle (21,600’).
There are 1.047 inches per minute of angle at 100 yards (1.047 inches/minute).
For most shooting we can use 1 MOA=1” @100 yards

One thing to be aware of is that some scopes, including some higher-end models, are calibrated such that an adjustment of 1 MOA corresponds to exactly 1 inch, rather than 1.047". This is commonly known as the Shooter's MOA (SMOA) or Inches Per Hundred Yards (IPHY). While the difference between one true MOA and one SMOA is less than half of an inch even at 1000 yards


Milliradians are a unit of angular measurement equal to 1/1000 of a radian
There are 6.2832 radians in a circle
Each radian is chopped up into a thousand pieces, then there are 6.2832 x 1000 = 6,283.2 milliradians in a circle
One Mil =3.438 MOA @ 100 yards
One MOA = 1.047” @ 100 yards
One Mil = 3.6” @ 100 yards (3.438 X 1.047=3.6”)


MOA/MIL Relationship
Remember, at 100 yards, each 1 mil angle = 3.438 minutes of angle (moa), and each 1 minute of angle has a length of 1.047 inches. Multiply those two numbers together:
3.438 minutes x 1.047 inches = 3.6 inches = 1 mil at 100 yards
I hope you’re starting to see the relationship between mils and moa

The Precision Marksman can utilize his scope reticle to determine range, compensate for the effects of gravity and wind and holds for moving targets
Once he establishes a zero with his rifle and ammunition combination and collects data at known ranges, he can compensate for the effects of gravity and wind by referring to his known data or referring to published theory charts or ballistic programs.

https://becomingriflemen.files.wordpress.com/2010/02/figure26.jpg

[mark5pt56]

Read and read
From people more intelligent than I.
Oh, as I mentioned earlier as we tend to stay with what we know. The 175 SMK is a good bullet-but look at the Berger line, do the chart with a 175 SMK and compare to a Berger 185 or a Hornady 178 BTHP, other Berger weight, etc also.


http://www.arcanamavens.com/images/DA/DAChart2.jpg


READ ALL OF THIS AND NOTE IMPORTANT FACTORS

http://www.arcanamavens.com/LBSFiles/Shooting/Downloads/DA/

[MBtech]

Thanks for taking the time to put that together. Absolutely awesome.

[skywalkrNCSU]

Thanks for taking the time to put that together. Absolutely awesome.

+1

That is really great information, thanks a lot.

[USMC_Anglico]

I will also throw in a vote for Mil/Mil setups. Add a LRF and a ballistic calc app for your smartphone and it's amazing what can be accomplished. I am shooting a 18" Krieger .308 barelled AR10 with a Bushnell HDMR/H59 scope, Leica LRF and shooter on an iphone. I have no problems making first round hits on steel at 600-700, haven't been on a range with more distance yet. I would never go back to MOA, mils make it too easy to calculate everything, since it's all units of 10. Also make sure to build range/dope cards, never know when the electronics will fail.

[Hootiewho]

I would also add, in shooting with a lot of the regulars in GA, it is split about 50-50 between mils and MOA. In fact at one match, I could only find one guy to call for my shots using mils. Everyone else there was using NF MOA scopes. NF being in Lavonia, they are VERY predominate in GA. I like mils, and run the H59 in my S&B personally.

I would also add that as far as companies I have seen who are VERY BIG shooting supporters, you'll see a lot of Bushnell and Vortex reps at the big events. That also says a lot to me personally.

[SeriousStudent]

My thanks to the posters as well, this is a very helpful thread.

[Little Creek]

Thanks to one and all. I am old, 63.5, retired Federal agent (25 years), and not going to war. I have been shooting for over 40 years. I have yet to try long range shooting. I choose a NF SHV 5-20x56 with MOAR because of the reputation of the company and the scopes. If money were no object I would have bought a NF FFP scope with Mil/Mil at well over twice the price. As it is, this is the most expensive scope I have ever owned and I am going to give it a go. After all this is a hobby for me and I will never be a world champion in the long range game. Thanks again, I assure you all I will use the data, web sites, and advice offered by the SMEs who have been kind enough to offer it.

[ubet]

The only true way to know what your dope is gong to be is map your cartridge. Shoot at known distances and write your dope down to include humidity, da, wind, temp, barometric pressure, and distance. Keep good logs on your rifle and the elements. Jbm and ballistic calc are good to get you close, but they aren't your weapon.

[taliv]

while that is more or less true, it is also highly problematic for practical long range shooters.

even if you had a 1400 yard flat range, and could test at every range, think about what that would mean. let's say you test every 25 yards to 1000 yards. if you only shoot 3 round per distance instead of a group that's 120 rounds. doesn't sound too bad until you realize you've only mapped one environmental condition, so you're still interpolating for intermediate distances, like say, 913 yards and for changes in temp and alt. worse, the velocity changes over the life of the barrel enough to matter. depending on caliber, every couple hundred rounds, you would probably need to check it again.

the best solution isn't perfect either, but until something better comes along, it seems running a ballistic calculator and being able to true up the velocity over the barrel life, with reasonably frequent confirmation at various distances is the way to go.

the calculators sure can be frustrating sometimes though

[Eurodriver]

the calculators sure can be frustrating sometimes though

True.

I think there is truth to both of your points. I don't think ubet was implying that one should shoot at 25 yard increments out to 1,000 and then rush off to the range every time the weather changes to test new zeros (Most people don't shoot paper beyond 300 yards or so anyway, and An 18" Gong is 3 MOA at 600 yards...) it's just that there are a billion people on the internet who zero their rifle at their local 100 yard range and then spout off BS like "Yeah, I got my calculator I can make hits out to 1000" even though they've never tried it. People need to shoot the gun to confirm is what he is implying, I suspect.

The flip side is that, with a good calculator, you can enter in your actual confirmed dope at certain yards combined with the environmental conditions during that dope fire and then upload current weather conditions to the calc and it will give you the relative trajectory to your old dope. That will certainly get you close enough for government work...

[ubet]

while that is more or less true, it is also highly problematic for practical long range shooters.

even if you had a 1400 yard flat range, and could test at every range, think about what that would mean. let's say you test every 25 yards to 1000 yards. if you only shoot 3 round per distance instead of a group that's 120 rounds. doesn't sound too bad until you realize you've only mapped one environmental condition, so you're still interpolating for intermediate distances, like say, 913 yards and for changes in temp and alt. worse, the velocity changes over the life of the barrel enough to matter. depending on caliber, every couple hundred rounds, you would probably need to check it again.

the best solution isn't perfect either, but until something better comes along, it seems running a ballistic calculator and being able to true up the velocity over the barrel life, with reasonably frequent confirmation at various distances is the way to go.

the calculators sure can be frustrating sometimes though
Please don't get me wrong, I wasn't saying not to use a ballistic calc. What I was trying to spit out through my poor use of our language sometimes, is that you should get the hard data on the range first. Then go to your calc and you can put in all of the atmospheric conditions, the ranges etc and keep tweaking things until the calc matches your real world data. I know I had to drastically change my mv on jbm to get the dope I was seeing in the real world. I think I had to change it by 65 fps. Just my humble advice.

[taliv]

yep, i agree that makes sense. i guess i'm just a little sensitive to the issue because my match caliber only gets around 1800 rounds of barrel life. i really try to find ways to minimize the number of rounds it takes to get data i can be reasonably confident in. not just because it costs so much to replace barrels, but because it takes a while too and scheduling through the match season is difficult.

[ubet]

My first precision bolt rifle was a savage 12 in 300wsm, I shot 185gr Vedder Berger vlds out of it, it lasted for 962 rds. Then the barrel went, and when it did it went hard. I feel for you that sucks. I like the ol 308, the barrels last forever.

[Failure2Stop]

Another significant factor is that it is harder than most assume to achieve perfect POA/POI during zeroing. A slight POI shift from the reticle can make ballistic data look wrong.
Having the reticle slightly out of perfect alignment with the barrel can make holds disagree with pure ballistic data, as can having the elevation and windage mechanisms not in perfect alignment if dialing.

Truing ballistic data is important if you are going to be successful at distance.

I am a big fan of the Kestrel 4500 with Applied Ballistics. Using it in conjunction with a tablet/smart phone is the optimal solution as far as user interface, but the 4500 alone will do the same job. Truing at 300-500, and at trans-sonic range (if you shoot that far), will teach the ballistic software exactly what is happening through the arc, and will make it more accurate in predicting POI at distance. If you don't have precise target distance data, your quality of output will be greatly reduced. Be sure to pay attention to mid-range wind, as a shooter location wind (which must always be factored in) gathered from the Kestrel may not be the only wind that the projectile is affected by.

All of that said, actual shooting data is crucial. Even the best ballistic software cannot perfectly tell you where the projectile will go. Gather and record all environmentals, and make note of the difference between the ballistic data and actual POI. If at all possible, confirm your 100 meter zero with a few 5-round groups before going long. Significant changes in altitude/density will alter zero, and shooting with a non-zeroed rifle at long range is an exercise in frustration and will give irrelevant data for future use. If you tell the AB software that you are zeroed at 100m with no offset, then that's the data that it's going to push to you, regardless of whether that is true or not.

[taliv]

heh, that's true. when i used S&B PM2 5-25x, i could zero in just a shot or two, but it was always between tenths, so always just a hair high or low

when i got the vortex gen2 that doesn't have the discrete clicks when zeroing and you can set it exactly right, it would take me like 30 rounds to zero just cause it would keep trying to get it absolutely perfect. ugh

[waveslayer]

heh, that's true. when i used S&B PM2 5-25x, i could zero in just a shot or two, but it was always between tenths, so always just a hair high or low

when i got the vortex gen2 that doesn't have the discrete clicks when zeroing and you can set it exactly right, it would take me like 30 rounds to zero just cause it would keep trying to get it absolutely perfect. ugh
That's why I miss my MOA turrets... switched to Mils, but it's spilt milk mostly

[TheBelly]

168 vs 175: The drawback of the 168 is that it doesn't do well with trans-sonic stability. Saying the 168 doesn't do well after a certain distance really comes from the fact that the 168 usually goes trans-sonic at those ranges. Here's the thing, though... Every rifle and load combo is different. Getting the MV from your particular rifle/ammo combo is one of the key components to utilizing an electronic ballistics solver/computer to aid in predicting what the bullet will do. Then you can find the real distance at which you can expect the destabilization from the trans-sonic portion of flight to occur.

Kestrel: Any computer is only as good as the data that's put into it. Poop in = poop out. Having a personal weather station (Kestrel) is a good idea. Be sure to let it adjust to the environment for a couple of minutes. Don't pull it out of the bag and then immediately get the readings. Certain readings matter a lot, others don't matter so much. I have found through experience that the humidity doesn't matter a whole lot. I just plop it at 50% and that will be that. The optics height over the boreline measurement is pretty important. I get that as accurately as I can. Also, don't discount having the optic as low as possible to the boreline without it obstructing anything. Overall, I encourage everyone to play with the environmental and gun settings so you can see the affect those settings have.

Manufacturers Stated Ballistic Coefficients: I've noticed that a lot of bullet manufacturers state the G1 BC of their products. That's all well and good, but the G7 BC is better suited to the modern boat-tail styled projectiles, especially when the distances are getting out there to 500, 600, and beyond (AND when the target is a MOA-sized or smaller). If possible, I default to the BCs that are displayed by reproduceable empirical data. Bryan Litz (Applied Ballistics) has done EXTENSIVE work and certain computers can include his work into the equation. If possible, I use G7 BCs and if possible I use Litz's BCs.

Again, getting the right data is important when working with a computer. Poop in = Poop out.



*** this is all IMHO, based on my experience, and YMMV. (that's the disclaimer, right?)

[Failure2Stop]

Excellent point on the Litz data, especially with .308.

Also, preliminary results only, but it looks like the new tipped 168s are doing much better in the trans sonic range than previous SMKs.

From Tapatalk:
Jack Leuba
Knight's Armament Company: Military/Govt Product Liaison
F2S Consulting: Director of Shooting Stuff

[ubet]

If you have a smartphone look at an app called shooter it's a really good easy to use ballistic calc.

[williejc]

Now I realize why I don't shoot at stuff beyond 200 yards. Years ago I had a very fine Browning .270 BLR scoped with a Leupold 6x. I shot deer, hogs, and most anything else that would stand still. Invariably, when hunting as a guest on other's leases, somebody would ask me why in the hell did you buy a lever action 270. With a straight face I'd always say that I liked the stock, and upon further questioning, I'd explain that I sighted it on a stump at 100 yards, and that it sure did shoot true. I don't have enough sense to do long range shooting requiring a calculator.