Necessary precision to kill something

[Alex Wheeler]

The guy's point is your hunting rifle is not a 1/4 MOA rifle if you shoot 30 shots; the 1000 yard record benchrest ten shot aggregate is not even 1/4. The record heavy gun 30 shot aggregate is 2.0057", or .33 MOA. So if you are doing better than that, you need to start collecting some ribbons and trophies.

But I agree, a rifle that shoots groups three times larger than another one is going to be more difficult to connect at long range.

Thats not a good way to look at this. In Benchrest we are shooting very different rifles and cartridges. The formats different too. You dont get to decide when you get to shoot in competition. If its blowing and its your relay you shoot. That 10 shot agg is actually 6 or 10 10 shot groups fired across many months, days, and conditions. Piont is, if they shot 3 shots and could pick when to shoot, those aggs would be tiny. To test your hunting rifle which gets much hotter and shoots much slower between shots you would be better off evaluating it with 10 3 shot groups than one 30 shot. That 30 shot is more a test of conditions than the rifle. While I dont go 30, my last 300 prc I had I tested for cold bore 3 shot groups at 1k. I took it out 4 times on different days, layed it on the bipod and shot 3 cold bore. I shot those 4 groups from 3.5 to 4 inches at 1k. Thats what I look for in a hunting rifle. Small 3 shot cold bore groups at distance. I dont care what it would do for 30 at 100 or any other range. Dont even care what 30 would do in Br. We only shoot 5 or 10 at a time. And yes theres a difference in how you tune for 5 or 10. In the hunting stuff you dont tune for tiny, you tune for agg. So in many cases those 10 shot groups are already at the biggest by the first few shots. They wont shoot small for 5 but they wont shoot big for 10. Thats what you want. Stability. But dont test with big groups, use 3 shots but do it multiple times and on different days. Tough to find a 1/4 minute 1k rifle. Sub .5 is realistic. 1/4 at 600 is achievable. I really like to see 1/3 at my max range.

 

[69precision]

This exactly what I took away from this podcast. That ethical hunting should be limited to sub 500 yards due to OUR inconsistencies of precise wind calls.

I agree the limit for most people for hunting is likely a couple hundred yards less than they think it is. That said an absolute limit seems like it would vary significantly based on caliber. Across every ability of shooter, it's just ballistics that they can hit the vitals at further range with a 50bmg than a 308.

 

[Huntnful]

Thats not a good way to look at this. In Benchrest we are shooting very different rifles and cartridges. The formats different too. You dont get to decide when you get to shoot in competition. If its blowing and its your relay you shoot. That 10 shot agg is actually 6 or 10 10 shot groups fired across many months, days, and conditions. Piont is, if they shot 3 shots and could pick when to shoot, those aggs would be tiny. To test your hunting rifle which gets much hotter and shoots much slower between shots you would be better off evaluating it with 10 3 shot groups than one 30 shot. That 30 shot is more a test of conditions than the rifle. While I dont go 30, my last 300 prc I had I tested for cold bore 3 shot groups at 1k. I took it out 4 times on different days, layed it on the bipod and shot 3 cold bore. I shot those 4 groups from 3.5 to 4 inches at 1k. Thats what I look for in a hunting rifle. Small 3 shot cold bore groups at distance. I dont care what it would do for 30 at 100 or any other range. Dont even care what 30 would do in Br. We only shoot 5 or 10 at a time. And yes theres a difference in how you tune for 5 or 10. In the hunting stuff you dont tune for tiny, you tune for agg. So in many cases those 10 shot groups are already at the biggest by the first few shots. They wont shoot small for 5 but they wont shoot big for 10. Thats what you want. Stability. But dont test with big groups, use 3 shots but do it multiple times and on different days. Tough to find a 1/4 minute 1k rifle. Sub .5 is realistic. 1/4 at 600 is achievable. I really like to see 1/3 at my max range.

I like it. Was just talking to @Barehandlineman11 and he aligns with your thoughts also and explained it well. 1/4 MOA rifles absolutely exist. However, 1/4 MOA shooters, and more importantly 1/4 MOA conditions over several shooting sessions isn't as likely. Makes sense to me

 

[LRNut]

Thats not a good way to look at this. In Benchrest we are shooting very different rifles and cartridges. The formats different too. You dont get to decide when you get to shoot in competition. If its blowing and its your relay you shoot. That 10 shot agg is actually 6 or 10 10 shot groups fired across many months, days, and conditions. Piont is, if they shot 3 shots and could pick when to shoot, those aggs would be tiny. To test your hunting rifle which gets much hotter and shoots much slower between shots you would be better off evaluating it with 10 3 shot groups than one 30 shot. That 30 shot is more a test of conditions than the rifle. While I dont go 30, my last 300 prc I had I tested for cold bore 3 shot groups at 1k. I took it out 4 times on different days, layed it on the bipod and shot 3 cold bore. I shot those 4 groups from 3.5 to 4 inches at 1k. Thats what I look for in a hunting rifle. Small 3 shot cold bore groups at distance. I dont care what it would do for 30 at 100 or any other range. Dont even care what 30 would do in Br. We only shoot 5 or 10 at a time. And yes theres a difference in how you tune for 5 or 10. In the hunting stuff you dont tune for tiny, you tune for agg. So in many cases those 10 shot groups are already at the biggest by the first few shots. They wont shoot small for 5 but they wont shoot big for 10. Thats what you want. Stability. But dont test with big groups, use 3 shots but do it multiple times and on different days. Tough to find a 1/4 minute 1k rifle. Sub .5 is realistic. 1/4 at 600 is achievable. I really like to see 1/3 at my max range.

The podcast said you don't have to shoot 30 shots at once - go ahead and shoot three shot groups but do it on the same target over a 10 day period. You still think that would be 1/4 MOA?

As for the 600 aggregate, it was shot on June 13, 2021. If I recall Glen Kulzer said conditions were perfect.

The fact we don't shoot 30 shots at an animal is not the point. Thirty shots tells us what that rifle can do - that is why I said shoot a 30 shot group over a period of 30 days. In your example, you shot a great four shot group over four days. Do that 26 times and calculate your hit rate on a 10" target.

I can flip a coin three times and it will land heads all three times once every eight times I try. The odds of getting heads 30 times in a row is once in just over a billion (at one second per flip, you won't live long enough to see it even if you started at birth and didn't eat, sleep, or shoot). Same applies to a three shot group. Unless you superimpose your groups over themselves, they really mean nothing.

 

[LRNut]

I like it. Was just talking to @Barehandlineman11 and he aligns with your thoughts also and explained it well. 1/4 MOA rifles absolutely exist. However, 1/4 MOA shooters, and more importantly 1/4 MOA conditions over several shooting sessions isn't as likely. Makes sense to me

No, it doesn't make any sense at all. Let's assume bullet groups are normally distributed. I shoot a three shot group where two land dead center and one is 1/4 MOA from dead center (the best possible 3 shot group that is 1/4 MOA). I have a 1/4 MOA group. However, the standard deviation for this is .144, which means, based on this extremely small sample, that 68% of my future shots will land plus or minus .144, which creates a group size of .288 MOA. Close enough for government work; let's call that 1/4 MOA. But that is only 68% of fired bullets. 90% will land within .23 MOA of center (.46 MOA). Nearly all, or 99%, will land plus or minus .432" from dead center, or close to the dreaded MOA rifle (.864").

Let's suppose you can call the wind within 1 mph and your wind drift is 4" @1000 yards per mile of wind. 68% of the time you are going to hit the deer simply because 68% of your bullets are within 1.44" of dead center. 10% of your shots are going to hit at least .25 MOA from dead center, which means half are going to miss due to wind. I am not factoring in wind that changes during TOF or between your wind call and the trigger pull. If your wind call is off by 2 mph, your entire group is displaced 8" or nearly the entire kill zone of a deer. Still half the time you kill it because half your bullets are hitting left or right of dead center. The "fringe" of the group, the 2" that is still on target gives you a few more percent chance of a it. Pretty close to the odds the podcaster revealed. And to his point, that is why wind call skills are far more important than accuracy.

Now suppose another rifle shoots a 30 shot group that measures .4 MOA (almost double your group size!). You might think your rifle is the better LR weapon - after all, yours is 1/4 MOA. But let's suppose of those thirty shots, 5 hit dead center, 20 hit .1 MOA from center, and 5 hit .2 MOA from dead center. The standard deviation of those 30 is .063. That means 68% of our shots will land in a .12 group. 99% will land in a .378 group (less than 1/2 MOA but almost identical to our 30 shot group). Which rifle do you want now? The 1/4 MOA 3 shot or the 30 shot .4 MOA?

Incidentally, with the 1/4 MOA (3 shot group) rifle you need to call the wind within .17 mph to hit 99% of the time; with the 30 shot .4 MOA rifle your allowable with error (99% hit rate) increases to .77 mph. (Deer at 1000 yards with a 10" vital area.)

Hopefully this illustrates the point in the podcast that 3 shot 1/4 MOA groups don't translate into much in real life.

 

[Huntnful]

No, it doesn't make any sense at all. Let's assume bullet groups are normally distributed. I shoot a three shot group where two land dead center and one is 1/4 MOA from dead center (the best possible 3 shot group that is 1/4 MOA). I have a 1/4 MOA group. However, the standard deviation for this is .144, which means, based on this extremely small sample, that 68% of my future shots will land plus or minus .144, which creates a group size of .288 MOA. Close enough for government work; let's call that 1/4 MOA. But that is only 68% of fired bullets. 90% will land within .23 MOA of center (.46 MOA). Nearly all, or 99%, will land plus or minus .432" from dead center, or close to the dreaded MOA rifle (.864").

Let's suppose you can call the wind within 1 mph and your wind drift is 4" @1000 yards per mile of wind. 68% of the time you are going to hit the deer simply because 68% of your bullets are within 1.44" of dead center. 10% of your shots are going to hit at least .25 MOA from dead center, which means half are going to miss due to wind. I am not factoring in wind that changes during TOF or between your wind call and the trigger pull. If your wind call is off by 2 mph, your entire group is displaced 8" or nearly the entire kill zone of a deer. Still half the time you kill it because half your bullets are hitting left or right of dead center. The "fringe" of the group, the 2" that is still on target gives you a few more percent chance of a it. Pretty close to the odds the podcaster revealed. And to his point, that is why wind call skills are far more important than accuracy.

Now suppose another rifle shoots a 30 shot group that measures .4 MOA (almost double your group size!). You might think your rifle is the better LR weapon - after all, yours is 1/4 MOA. But let's suppose of those thirty shots, 5 hit dead center, 20 hit .1 MOA from center, and 5 hit .2 MOA from dead center. The standard deviation of those 30 is .063. That means 68% of our shots will land in a .12 group. 99% will land in a .378 group (less than 1/2 MOA but almost identical to our 30 shot group). Which rifle do you want now? The 1/4 MOA 3 shot or the 30 shot .4 MOA?

Incidentally, with the 1/4 MOA (3 shot group) rifle you need to call the wind within .17 mph to hit 99% of the time; with the 30 shot .4 MOA rifle your allowable with error (99% hit rate) increases to .77 mph. (Deer at 1000 yards with a 10" vital area.)

Hopefully this illustrates the point in the podcast that 3 shot 1/4 MOA groups don't translate into much in real life.

I agree. I was just saying that even though a gun itself, may have the ability to shoot 1/4 MOA. A shooter getting behind it multiple different times, to shoot multiple groups over varying conditions in the time it takes to shoot those, lets say 30 rounds. Would never align to shoot 1/4 MOA. Wasn't at all talking about a 3 shot 1/4 MOA group.

 

[Barehandlineman11]

The podcast said you don't have to shoot 30 shots at once - go ahead and shoot three shot groups but do it on the same target over a 10 day period. You still think that would be 1/4 MOA?

As for the 600 aggregate, it was shot on June 13, 2021. If I recall Glen Kulzer said conditions were perfect.

The fact we don't shoot 30 shots at an animal is not the point. Thirty shots tells us what that rifle can do - that is why I said shoot a 30 shot group over a period of 30 days. In your example, you shot a great four shot group over four days. Do that 26 times and calculate your hit rate on a 10" target.

I can flip a coin three time and it will land heads all three times once every eight times I try. The odds of getting heads 30 times in a row is once in just over a billion (at once second per flip, you won't live long enough). Same applies to a three shot group. Unless you superimpose your groups over themselves, they really mean nothing.

Over complicating things. At what point do you call a gun 1/4 moa or even .5 moa. Going off many of these podcast some saying you need more data. Most guns run out of tune before you would in theory have this data. So at what point do you look back and say thats a 1/4 moa gun? Barrel worn out?. If you can go shoot your gun today 1000 3 shots into a 2.5 circle and do it tomorrow and tomorrow. Aside from your impact being high low left or right each and every day thats a 1/4 moa gun. Your high left right low is your not calling the wind right or mirage. Thats why load work past 600 is better then 100

 

[LRNut]

Over complicating things. At what point do you call a gun 1/4 moa or even .5 moa. Going off many of these podcast some saying you need more data. Most guns run out of tune before you would in theory have this data. So at what point do you look back and say thats a 1/4 moa gun? Barrel worn out?. If you can go shoot your gun today 1000 3 shots into a 2.5 circle and do it tomorrow and tomorrow. Aside from your impact being high low left or right each and every day thats a 1/4 moa gun. Your high left right low is your not calling the wind right or mirage. Thats why load work past 600 is better then 10

The podcast was created by Applied Ballistics. These guys absolutely know what they are talking about.

It might seem complicated to you but it is fairly simple math - the podcaster said you need a sample of 30 to come up with meaningful conclusions (and anyone who has ever had a statistics class or 6 sigma training is taught this). In my example, the statistical "bell curve" says 99% of all shots are just under .4 MOA - and the actual group was .4 MOA. Even the best possible 3 shot group could not "guarantee" precision better than a 30 shot .4 MOA one.

The OP podcast is not intended to define a 1/4 MOA rifle - if you want to call a 3 shot group a 1/4 MOA rifle, go for it. But don't extrapolate those three shots to calculate your odds of hitting a deer at 1000 yards, because it doesn't tell you much of anything other than it is more accurate than a rifle that shoots 1/2 MOA 3 shot groups.

Bryan Litz has written that group size in immaterial; what is important is the mean radius to center. Google it if you are curious. But what does he know anyway; he is only the chief ballistician at Applied Ballistics.

I am just stunned so many people here think a three shot group characterizes the entire population of shots. Imagine you have a box of 20 cartridges...you pick three and shoot them. Two define the extreme spread, and from that you are going to conclude the other 17 are going to land inside those two shots?

Again, look at the IBSA ten shot record sized group: it is just over .25 MOA. Why do you think they shoot 10 and not 3?

Just to amuse myself, I will throw this out to anyone: you come to my place in CO. You shoot three shots in the morning at my 910 yard gong, under calm conditions - or you shoot throughout the day when conditions are perfect. If you shoot a 2.275" (1/4 MOA) group, we grill some burgers and drink some beer that evening - you stay overnight and do it again in the morning. If you repeat that, you do it one more time the next day. If all three groups are 2.5," I will give you $1000 and pay for you $500 in travel expenses. If not, you pay me $200 and pick up your own expenses. Any caliber but rifle must be 15 lbs or less and shot off a bipod. I have a concrete patio so you will have a perfect position.

 

[Barehandlineman11]

You missed my point and i wont continue the argument. I never said one 3 shot group was good enough to be clear.

 

[blvette75]

the bc is a reflexion of how streamlined they are my understanding is the 1.00 is the top of the bc's and supposed to be a 750gr .50 cal bullet so they all seem to have a better bc reguardless of how streamlined they are when they are heavier which usually means larger caliber. The bc also reflects how they do in the wind so higher bc means less wind drift and the ability to retain velocity a good example is the heavy 338 bullets compaired with the heavy 243 bullets both being boattail.

Thank you for your explanation.

 

[blvette75]

I know that question is not to me. But, I'd offer you take a look at the drop curves for your bullet. The farther out you're shooting the greater the angle of the target's cross section you're trying to impact.

Some people can almost see it ... dropping a bullet on target -vs- shooting it. I worked for years with an engineer who developed the Navy's software to do that with their BIG guns. It requires a genius I can't even think of holding a candle to.

ETA: I called that fella and he told me tell you this, "Calculate the effect of spin drift (BC ... flight time ... twist rate ... projectile length ... air density). Doing that will give you the legs to answer all the questions you have on the subject by yourself." Of course there was probably 45 minutes of other stuff that were completely over my head. Whoever knew you could calculate a shot from a platform on a rolling sea ... shoot 25 miles ... and drop a 2,000lb round within a hundred yards of what you were aiming at?

Thanks very much for the words of wisdom. I remember back in the day, was going for a shot on a deer was very windy and all of the sudden the wind just stopped. I took my shot uncompensated for the wind and was able to harvest the deer and was just thankful the wind stopped for my shot. I should probably invest in one of those new gadgets that measures the wind at distance, as I go deeper down this long range hunting rabbit hole.

 

[Beluebow]

But what does he know anyway; he is only the chief ballistician at Applied Ballistics.

You mean the same guy that said tuners don't work.

 

[Alex Wheeler]

The podcast said you don't have to shoot 30 shots at once - go ahead and shoot three shot groups but do it on the same target over a 10 day period. You still think that would be 1/4 MOA?

As for the 600 aggregate, it was shot on June 13, 2021. If I recall Glen Kulzer said conditions were perfect.

The fact we don't shoot 30 shots at an animal is not the point. Thirty shots tells us what that rifle can do - that is why I said shoot a 30 shot group over a period of 30 days. In your example, you shot a great four shot group over four days. Do that 26 times and calculate your hit rate on a 10" target.

I can flip a coin three times and it will land heads all three times once every eight times I try. The odds of getting heads 30 times in a row is once in just over a billion (at one second per flip, you won't live long enough to see it even if you started at birth and didn't eat, sleep, or shoot). Same applies to a three shot group. Unless you superimpose your groups over themselves, they really mean nothing.

Glenn shoots 1000, not 600. Aggs are shot accross many matches and days, not a single day in 1000. 600 does shoot an agg in a day. Glenns my friend, I build his rifles, and was at all those matches. The things Im saying are just my opinions from someone that builds these rifles as a career. I dont have a podcast though.

 

[Barehandlineman11]

Gotta have podcasts too know what your talking about these days