Issue with Shooter App

[Big Al]

Guys,

 

Im using the Shooter App which is my first venture into ballistic software.

 

Im using 55gr VMax in .223 and have taken the velocity and BC data from the Hornady website - 3240fps and 0.255 respectively. My rifle is shooting 0.75" high at 100yds to 0.5MOA or less and my scope height is 1.85" which is measured accurately. The scope is a Sightron with 1/4MOA clicks.

 

The problem tonight is that Shooter told me I needed 2 clicks up to get out to 200yds but that put my group 1" high. I shot a couple of pigeons later at 208 & 201yds with good kills by aiming dead on without any clicks up. This has me thinking that there could be three unanswered variables

 

1. My velocity varies from that of Hornady, Im running a 20" barrel.

 

2. The BC of the bullets isnt as Hornady suggests

 

3. My scope clicks are not true 1/4 MOA

 

I tweaked the velocity and BC a touch to get the reading at 200yds I felt I needed (zero clicks required) but am wondering if this is the best way to do things? I feel I have all the other data correct, I may have the chace to get the ammo chronographed this weekend which would help but any suggestions or other likely causes would be appreciated.

[M99]

You simply cannot rely on data from a book/website. You need to chrono your loads. The BC will be about right, but check out Litz's BC for your projectile.

 

With these balistic programs, they are only as good as the data you put in, this needs to be tailored for your rifle and weather conditions.

[gbal]

Al,Mike is right-thee are several of these 'problems' every month!They all come from some mismatch between the ballistic programs 'data/program' and what the actual rifle /ammo is doing-obviously,and the discrepancy is always in the shooter input-velocity eg.Here'e Hornady's trajectory for their 55g Vmax load,3240fps,BC (G1).255;drop/drift:

 

100y 1.4/1.1 200 0/4.6 300 7/10.9 400 21.4/20.8

 

It is no easy to get a secure zero at 100-the shot dispersion of 1/2 inch may distort things-you'd do better with 10 shots at 200-though there simply is no substitute for live firing at the various distances to check.

Velocity is another factor-though your findings don't suggest you have reduced velocity,as drop is less than program.Need to check-with reliable

G1 BC is probably what program is using-manufacturers just vary in what they report-BC s not really a constant ,and varies over velocity a little..(ie G1 varies,not just that G1 differs from G7.you can't really check it independently.)

Sightrons are usually pretty good-anyhow,it's what you have and must use.(that's why replicability matters so much,more really than absolute accuracy in clicks value.

 

Rifles/ammo combinations with scopes and shooters are not clones,and programs will only get close,at best unless there is an exact input and program match.AS already said,since you are shooting to 300y or so,the definitive way is to set out paper at ranges and see where the holes actually are.Program is good for telling whee to locate the paper,though you will not have more than 7-12 inches drop/drift at 300y.Once you have that firing data,enter it and get a trajectory based on your performance.Use that,if you don't have enough actual firing data,eg every 25 y).

The main source of discrepancy from predicted to reality,is that very small 'errors' of measurement are overlooked at short ranges,hence 'out by a couple of clicks'. Holes on paper are the truth.

g

[Big Al]

Thanks guys, I see where you coming from and agree that real world results with holes in paper will tell the truest story, providing I can do my bit as the shooter.

 

Then again, if I have already got results from my 100 & 200yd groupings and I can rules out some variables like bullet weight and distance to target then surely we can arrive at the other figures by equation?

 

If you take the scope out of things then bullet drop at distance will be effected by only a couple of factors, its weight, velocity and BC?

 

If I knew the velocity or BC for sure then fudging the opposite one within the program until it reads the same as my real world results would be what is needed?

 

Im not saying anyone is wrong here, Im just trying to rationalise my thinking and appreciate people taking the time to reply

[Gandy]

Big Al,

 

This may sound silly but if you have set your zero for 100 yrs when it shoots 1/2 in high that would about explain it away as its really about zero'd for 200 yards.

 

Andy

[gbal]

Big Al,

 

This may sound silly but if you have set your zero for 100 yrs when it shoots 1/2 in high that would about explain it away as its really about zero'd for 200 yards.

 

Andy

Andy,Hornady's data don't fit that-you would need a 1.4 inch high at 100 for 200 zero (even this bullet in a swift at 3680 still needs .9 at 100 for 200 zero.But you touch on the issue of accurate measuring of just what POI etc is at short ranges-and possibly some rifle differences...velocity likely involved.

 

That said,why is Al's trajectory seemingly superior from a shorter barrel -unless MV is higher,but it would have to be unfeasibly higher-see swift data!

 

Anyhow,short of test shooting out to 300,yes,given better input data you should be able to botch up some ballistic output that is closer to reality.....but there are other advantages to actually testing on paper,eg it tells you just what the whole package does-ie shooter error,often a major component,especially with wind,which can make such shots iffy-or give confidence,as the case may be.

No ballistics program gives a clear picture of shot dispersal-"group"-which is what is really needed to determine ethical range.

Gbal

[Big Al]

Big Al,

 

This may sound silly but if you have set your zero for 100 yrs when it shoots 1/2 in high that would about explain it away as its really about zero'd for 200 yards.

 

Andy

 

Shooter has the option to detail exactly how high or low you are shooting at your initial zero. If I shoot to .075" high at 100yds it brings me bang on at 185 using the Hornady data on velocity and BC, the Shooter app allows for this.

[Big Al]

Big Al,

 

This may sound silly but if you have set your zero for 100 yrs when it shoots 1/2 in high that would about explain it away as its really about zero'd for 200 yards.

 

Andy

 

Shooter has the option to detail exactly how high or low you are shooting at your initial zero. If I shoot to .075" high at 100yds it brings me bang on at 200, the Shooter app alows for this.

 

Andy,Hornady's data don't fit that-you would need a 1.4 inch high at 100 for 200 zero (even this bullet in a swift at 3680 still needs .9 at 100 for 200 zero.But you touch on the issue of accurate measuring of just what POI etc is at short ranges-and possibly some rifle differences...velocity likely involved.

 

That said,why is Al's trajectory seemingly superior from a shorter barrel -unless MV is higher,but it would have to be unfeasibly higher-see swift data!

 

Anyhow,short of test shooting out to 300,yes,given better input data you should be able to botch up some ballistic output that is closer to reality.....but there are other advantages to actually testing on paper,eg it tells you just what the whole package does-ie shooter error,often a major component,especially with wind,which can make such shots iffy-or give confidence,as the case may be.

No ballistics program gives a clear picture of shot dispersal-"group"-which is what is really needed to determine ethical range.

Gbal

 

Hopefully I will get some shooting at 100, 200 & 300 later today Geoerge, how many shots do you think is a fair judgement to form a group?

[gbal]

Shooter has the option to detail exactly how high or low you are shooting at your initial zero. If I shoot to .075" high at 100yds it brings me bang on at 200, the Shooter app alows for this.

 

 

 

Hopefully I will get some shooting at 100, 200 & 300 later today Geoerge, how many shots do you think is a fair judgement to form a group?

More is always better,but realistically 5 minimum,but 10 if you can-( especially if there is more than an inch of vertical)-allowing similar cooling etc-again the 'bonus' is more info also on bullet dispersal-though you won't often/ever be shooting even three rounds at the same bunny...unless you don't do all this testing first !! :-)

 

(do you mean .75" high at 100 (to be zero at 200)....most factory data is more like 1.5" high at 100 to be on at 200,for 55g/3250/223.

A 22/250 50g nosler BT (BC.238) @3850 gives .8 at 100,and 200 zero (but the extra 600 fps is way beyond the 223,I hope-and shows just how much extra velocity is needed for modest drop gains,around an inch or so-100fps is barely discernible on paper.)

Enjoy the testing.

G

[CZ Varminter]

Hi big Al. I use shooter and have done for four years. Honestly I believe it to be your velocity. You are indeed correct in inputting your "zero height" in at 0.75inch. This would allow for an approx point blank range of around 230yrds. So ignore the 2 clicks. Your good out to that then. Mine says the same for my 55gr SBK out of my 22-250. It's zero at 100 half inch high on zero height. Shooter has being bang on for me. Shot 8 steel gongs out to 600yrds with it this summer. Exact MOA dialled from info given, but same old Sokol rule applies put poo in get the same out. On your zero data also set your humidity to 50% that covers you for everything. And tbh humidity plays very little in the ranges for that calibre. Altitude and baro pressure on the day of zero are important, for accurate data. Most BC are accurate enough, so revert back to Chrony data for velocity.

 

Hope didn't waffle to much.

 

CZV

 

Any more help give me a shout.

[gbal]

Hi big Al. I use shooter and have done for four years. Honestly I believe it to be your velocity. You are indeed correct in inputting your "zero height" in at 0.75inch. This would allow for an approx point blank range of around 230yrds. So ignore the 2 clicks. Your good out to that then. Mine says the same for my 55gr SBK out of my 22-250. It's zero at 100 half inch high on zero height. Shooter has being bang on for me. Shot 8 steel gongs out to 600yrds with it this summer. Exact MOA dialled from info given, but same old Sokol rule applies put poo in get the same out. On your zero data also set your humidity to 50% that covers you for everything. And tbh humidity plays very little in the ranges for that calibre. Altitude and baro pressure on the day of zero are important, for accurate data. Most BC are accurate enough, so revert back to Chrony data for velocity.

Hope didn't waffle to much.

CZV

Any more help give me a shout.

I tend to agree-pragmatically,'but with the important addition that 'point blank' range depends on your tolerance for high low shots-nothing is zero/same all the way out.

The original issue was the mismatch between program and firing data,which is related,but different.

 

OK-with a centre hold on your target (rabbit) what +/- high/low shot can you tolerate and still get a solid hit-probably around 3 inches,maybe a bit less....so that's your determiner for 'point blank' range-your shots have to stay +/- less than an inch and a half....

and that will shorten your pb range quite dramatically-even with a 200 zero,drop at 300y is about 6 inches,at least (velocity does not change this much).

Remember that's a tolerance circle of three inches-and that includes everything-rifle's intrinsic accuracy,wind reading error and shooter twitch-and even then you are very close to just trimming fur with some shots.....draw a 'Gary'* outine of a rabbit,transfer onto an acetate,and check if all your shots on paper are 'kills'....when this is no longer so,you have found your longest range....

Of course,dialling in (or careful hold over etc) is the answer-beyond your 'point blank' range (well under 200y) hence you still need to know your actual drops-in real shot holes,at these distances.

The issue with point blank (loosely ansd misleadingly sometimes called 'fast and flat',is that nothing is,and there is no viable cartridge that will be a 4/4 (inches drop/drift) at 300,let alone 400,esp if wind is above 6mph-the hot numbers(Swift,hot loaded 223 wssm )will make 4" drop at 300-just! 223w will not.

Fox have a somewhat larger kill zone(?beer mat size?),and deer maybe more-but they are not typically shot at 3/400 yards,with a 223w-rightly so.

" The laws of physics are not ours to do with as we please-we must account for our shots,especially the unsuccessful."

 

gbal

 

* patent applied for,no chance :-)

acetate idea is me,based on shotgun pattern research (Bristow the art and science)

[CZ Varminter]

Hello mate, point blank as far I was aware has always been within inch and a half either way... Basically in my idiot terms point and shoot! Lol

[gbal]

Hello ,, point blank as far I was aware has always been within inch and a half either way... Basically in my idiot terms point and shoot! Lol

Well, I think it means the size of the critical kill zone in your target ( as per Boddington,Litz etc etc.).But it is just a convention-though it kind of makes some sense to allow for just what you are shooting,I'd have thought.

 

If you chose 3 inches ( 1 1/2 either way) then you won't be point blanking beyond about 250y;even with a 200 zero, 22 swift is 3.9 low at 300,240 WM is 4.9-basically almost nothing is better than 4" low,and very little beats 5" ( a 223 40 vmax @3800 is 5.5 low at 300 with 200 zero......

 

 

 

The term means,as you say point and shoot -or rather more better aim dead on and fire (no vert/horiz allowance-any appreciable wind just 'blows away" the above figures,of course.

 

But it assumes that will give a humane,fatal hit.....and surely that is a function of the size of the vital zone in particular species-it won't be 2 inches to 8 inches,but it won't be fixed at 1 and a half either.

But whatever it is,it's a real constraint on how far you can shoot-I have no problem with 1 1/2 inches,since it discourages long shots,always the ethical decision.

 

Litz shows that a .5 100y grouper will have a max guaranteed all shots in a 4" circle range of 248 yards-when all the shot dispersal factors go one way-or the opposite-and they will for some shots-you have to limit range to 248y.Of course,that assumes shooting competence etc,but beyond 248y some shots will be outside the vital kill zone even for a skilled shot. A three inch zone simply reduces the range well below 248y...most may well be good,but not all,and there is simply no way of predicting which won't-it is as likely to be the first,as the fifth.....of course, ballistic app programs don't tell you this-they simply cannot deal with shot dispersal/groups etc and assume every shot falls the same.Brian says no,quite correctly,as we all know-just how much dispersion there can be is perhaps a surprise,and 'group size'-as in 3 shots in .3 at 100y- is but one factor,and not typically the biggest.....

Isn't math great ("maths" give exactly the same)!

 

Gbal

[Murph]

Guys,

 

Im using the Shooter App which is my first venture into ballistic software.

 

Im using 55gr VMax in .223 and have taken the velocity and BC data from the Hornady website - 3240fps and 0.255 respectively. My rifle is shooting 0.75" high at 100yds to 0.5MOA or less and my scope height is 1.85" which is measured accurately. The scope is a Sightron with 1/4MOA clicks.

 

The problem tonight is that Shooter told me I needed 2 clicks up to get out to 200yds but that put my group 1" high. I shot a couple of pigeons later at 208 & 201yds with good kills by aiming dead on without any clicks up. This has me thinking that there could be three unanswered variables

 

1. My velocity varies from that of Hornady, Im running a 20" barrel.

 

2. The BC of the bullets isnt as Hornady suggests

 

3. My scope clicks are not true 1/4 MOA

 

I tweaked the velocity and BC a touch to get the reading at 200yds I felt I needed (zero clicks required) but am wondering if this is the best way to do things? I feel I have all the other data correct, I may have the chace to get the ammo chronographed this weekend which would help but any suggestions or other likely causes would be appreciated.

First of all I would use a g7 bc. The g1 bc will need 2 speeds Inputted depending on the distances in the field. Brian litz g7 bc for this bullet is 0.127 bc and if you need to input for stability the bullet length is 0.811. Input these into the program to start off with and try to get a shot out to say 400 yards then adjust your velocity to suit your real world data. I used g1 for a few years and found there was serious discrepancies between say 400 yard and 600 yard shots. On my old program I would have to have an MV of 3450 fps and if I shot out to say 6-700 yards I would have to have an MV of 3050fps for it to correspond in the real world. Me and my shooting friends have all changed over to g7 bc and have found them so much more accurate out to 750 yards with no fudging with speeds or bc. If you are using a bully that you can't find a g7 bc for then use this g1 x 0.512 which gives you your g7 bc. Hope this helps.

[gbal]

Murph,you are right G7 is a considerably better value-because G7 is based on s generic bullet shape that is closer to modern bullets -ie at least assume a relatively pointy bit at the front-the old G1 assumes the shape is like a 22rf ,blunt ,slightly rounded....Bryan Litz's values are based on real world shooting,but corrected to sea level,stated barometric pressure and temperature...

But when you take on board that BC is a continuous variable-just like velocity,and related to it-it changes continuously with bullet flight-reducing all the while. Good ballistic programs may incorporate that with various accuracy,so the G7 is a very much better close approximation to what 'your' bullet actually does than G1...assuming the input data is accurate,esp as distance increases-a 1% error may not show on target at 100y (though it is there,masked by bigger other factors) but will contribute cumulatively at long range(as will the bigger if variable,factors. factors-eg wind)

It's an exact science only when exact info is input ('exact' within the G7 assumptions).(don't forget fps will vary-maybe not a lot,negligible at 100,noticeable by 400 -program can't predict which shots,nor general 'dispersion' usually,and certainly not where in the group,a particular shot will fall,or which will be out of the group,when error factors all go one way.....sometimes called a flier....doing all this is what determines the 'point and shoot'/point blank-and why it is shorter than casual thinking-we don't compute all the error factors going one way....but they can,and do sometimes....and sometimes,partially cancel-but that's no problem/surprise.

 

gbal

[Murph]

Murph,you are right G7 is a considerably better value-because G7 is based on s generic bullet shape that is closer to modern bullets -ie at least assume a relatively pointy bit at the front-the old G1 assumes the shape is like a 22rf ,blunt ,slightly rounded....Bryan Litz's values are based on real world shooting,but corrected to sea level,stated barometric pressure and temperature...

But when you take on board that BC is a continuous variable-just like velocity,and related to it-it changes continuously with bullet flight-reducing all the while. Good ballistic programs may incorporate that with various accuracy,so the G7 is a very much better close approximation to what 'your' bullet actually does than G1...assuming the input data is accurate,esp as distance increases-a 1% error may not show on target at 100y (though it is there,masked by bigger other factors) but will contribute cumulatively at long range(as will the bigger if variable,factors. factors-eg wind)

It's an exact science only when exact info is input ('exact' within the G7 assumptions).(don't forget fps will vary-maybe not a lot,negligible at 100,noticeable by 400 -program can't predict which shots,nor general 'dispersion' usually,and certainly not where in the group,a particular shot will fall,or which will be out of the group,when error factors all go one way.....sometimes called a flier....doing all this is what determines the 'point and shoot'/point blank-and why it is shorter than casual thinking-we don't compute all the error factors going one way....but they can,and do sometimes....and sometimes,partially cancel-but that's no problem/surprise.

gbal

Murph,you are right G7 is a considerably better value-because G7 is based on s generic bullet shape that is closer to modern bullets -ie at least assume a relatively pointy bit at the front-the old G1 assumes the shape is like a 22rf ,blunt ,slightly rounded....Bryan Litz's values are based on real world shooting,but corrected to sea level,stated barometric pressure and temperature...

But when you take on board that BC is a continuous variable-just like velocity,and related to it-it changes continuously with bullet flight-reducing all the while. Good ballistic programs may incorporate that with various accuracy,so the G7 is a very much better close approximation to what 'your' bullet actually does than G1...assuming the input data is accurate,esp as distance increases-a 1% error may not show on target at 100y (though it is there,masked by bigger other factors) but will contribute cumulatively at long range(as will the bigger if variable,factors. factors-eg wind)

It's an exact science only when exact info is input ('exact' within the G7 assumptions).(don't forget fps will vary-maybe not a lot,negligible at 100,noticeable by 400 -program can't predict which shots,nor general 'dispersion' usually,and certainly not where in the group,a particular shot will fall,or which will be out of the group,when error factors all go one way.....sometimes called a flier....doing all this is what determines the 'point and shoot'/point blank-and why it is shorter than casual thinking-we don't compute all the error factors going one way....but they can,and do sometimes....and sometimes,partially cancel-but that's no problem/surprise.

gbal

Agree with you 100 percent on this one. I read an article about some American 1000 yard shooters who used the g1 bc with different velocities at different ranges was even more accurate than the g7 model. The logistics to correctly correlate these figures seemed to involve chrono graphs at extreme distances ie up to 1000 yards away from the firing position. As you say there is no ballistic program in the world that can calculate every variable that we have in the field or it would get very boring. I know in applied ballistics you can actually put in the extreme spread of your loaded ammunition into the equation but how can it calculate for the "fliers".

[gbal]

Murph,the G1is generally much inferior to the G7as the G7 is based on Boat tail shapes-as most longer range bullets (there are of course other Gs too). One merit of G7 is that it can be applied-or corrected- for all the variable speeds of the bullet in flight,and is -I think-Doppler derived (and standardised at sea level and temp/baro pressure-allowing a better comparison (rather than the marketing oriented 'highest posssible' G1 previously popular. I don't know how the chronos at 1000y would have survived,in amateur use!!

 

It should be possible to have a ballistics calculator that incorporates almost all the variables (latitude,east west shooting.....meplet size,boat tail length....) though I suspect not many shooters do all this! But even if it were all put in accurately,boredom would be much relieved by enjoying the mischief of essentially un- measurable wind speed and very local turbulence effects en route to the target (still a major source of error,as we all know).

The human neck-top is still an important bit of kit!

 

g

[Murph]

Murph,the G1is generally much inferior to the G7as the G7 is based on Boat tail shapes-as most longer range bullets (there are of course other Gs too). One merit of G7 is that it can be applied-or corrected- for all the variable speeds of the bullet in flight,and is -I think-Doppler derived (and standardised at sea level and temp/baro pressure-allowing a better comparison (rather than the marketing oriented 'highest posssible' G1 previously popular. I don't know how the chronos at 1000y would have survived,in amateur use!!

It should be possible to have a ballistics calculator that incorporates almost all the variables (latitude,east west shooting.....meplet size,boat tail length....) though I suspect not many shooters do all this! But even if it were all put in accurately,boredom would be much relieved by enjoying the mischief of essentially un- measurable wind speed and very local turbulence effects en route to the target (still a major source of error,as we all know).

The human neck-top is still an important bit of kit!

g

Yes the human neck top is an important bit of kit alright. It's a bit like a ballistic program ie sh&te in equals shi&te out lol

[Roe]

I see there is a lot of bashing of the G1. Have any of you ever done the math or are you just parroting? Here is an example done in various programs, feel free to check.

 

Bullet Lapua 6,5mm 139gr Scenar as this is an extremely well documented bullet.

Published G1 0,578. G7 0,29 used where possible if not Cd (radar data).

V0 835 msec at 12˚C changing 0,5 msec pr 1˚C.

Rifle zero 100m, 5 cm distance barrel/scope c-c.

Sight adjustment 0.1 MRAD or 1cm@100m.

Weather 990 hPa, rel air humidity 60%, temp12C .

Theoretical trajectory calculated by various programs with the above input, the results is number of clicks.

 

400m 600m 800m 1000m 1200m

Applied Ballistics (G7) 23 45 72 107 153

Shooter (G7) 23 46 74 109 155

Strelok Pro (G7) 23 45 72 106 150

Lapua Ballistics (Cd) 23 44 71 105 nil

G1 calculation 23 44 72 105 148

[Murph]

I see there is a lot of bashing of the G1. Have any of you ever done the math or are you just parroting? Here is an example done in various programs, feel free to check.

 

Bullet Lapua 6,5mm 139gr Scenar as this is an extremely well documented bullet.

Published G1 0,578. G7 0,29 used where possible if not Cd (radar data).

V0 835 msec at 12˚C changing 0,5 msec pr 1˚C.

Rifle zero 100m, 5 cm distance barrel/scope c-c.

Sight adjustment 0.1 MRAD or 1cm@100m.

Weather 990 hPa, rel air humidity 60%, temp12C .

Theoretical trajectory calculated by various programs with the above input, the results is number of clicks.

 

400m 600m 800m 1000m 1200m

Applied Ballistics (G7) 23 45 72 107 153

Shooter (G7) 23 46 74 109 155

Strelok Pro (G7) 23 45 72 106 150

Lapua Ballistics (Cd) 23 44 71 105 nil

G1 calculation 23 44 72 105 148

 

I found for my loading -223. That the numbers were somewhat different when it came to field conditions. I tried all my loads on g1 and had to input two different speeds to the program with a fixed bc to get the results I wanted.

[247sniper]

I had/have, a similar prblem with my .204. The ballistic programs would suggest i need 5.25 MOA for a 400 yard shot when in reality in the field it only 4MOA. I played and played with my setup, swapped scopes etc to try and sort it out, just could not get it right. In the end I just spent a few hours out on some targets out to 600 yards and collected my own accurate data which I know is correct. Now I know if im shooting a 425 yard rabbit I know exactly how much elevation i need.

 

Steve.

[Murph]

I had/have, a similar prblem with my .204. The ballistic programs would suggest i need 5.25 MOA for a 400 yard shot when in reality in the field it only 4MOA. I played and played with my setup, swapped scopes etc to try and sort it out, just could not get it right. In the end I just spent a few hours out on some targets out to 600 yards and collected my own accurate data which I know is correct. Now I know if im shooting a 425 yard rabbit I know exactly how much elevation i need.

 

Steve.

Out to 400 yards my speed had to 3450 fps to correlate. Then out to 700 yards it had to be 3050 fps. This was for 53 gr vmax. Although with the hornady 75 gr bthp the numbers are a lot closer. Maybe with a heavier projectile the g1 is more consistent throughout the ranges. With the g7 numbers there is no faffing about with 2 different speeds to get the same end result.

[247sniper]

Out to 400 yards my speed had to 3450 fps to correlate. Then out to 700 yards it had to be 3050 fps. This was for 53 gr vmax. Although with the hornady 75 gr bthp the numbers are a lot closer. Maybe with a heavier projectile the g1 is more consistent throughout the ranges. With the g7 numbers there is no faffing about with 2 different speeds to get the same end result.

 

 

Likewise, my .223 Ackley shooting 80 grain amax is almost bob on, weird