Hunting Accuracy?

[mhamlin]

Mikecr and others posted on the topic elsewhere on the site, but I stiil have question(s). I've been chasing speed and the perfect group size with my new rifle. I seem to only achieve one, or the other, at a time.

Mikecr's point has finally sunk into my thick skull. All of the animals I've killed were first shot hits, so why have I been using up the short barrel life of my 300 RUM...?

I read the Carlos Hathcock method of cold-bore accuracy and see how it will better suit my needs. I think my question is: do I only test for the lowest ES & SD at a given bullet/charge combination, or am I missing some other important detail.

Thanks, Mike

 

[Clark]

I drive 900 miles to where I will hunt a month early for target practice.
Each year I build a number of rifles and I have reloading in my vehicle.

I sight a rifle in and work up a load.
I back up further and further from the target.
When i THINK I can hit the kill zone at some range, I try that target the next morning. That is very cold bore shot early in the morning.

Then I do it in the afternoon when there is wind. I am trying to get qualified for some window of wind and range. When the wind is over 15 mph, I do not hunt... I just watch TV

With many rifles, that distance has been between 400 and 550 yards that i have qualified to shoot at game.

Before I came up with this process i was missing and wounding animals half the time at long range. Now it is all bang flop.

 

[g0rd0]

my pet load in my deer rifle is where I keep the scope dialed in. Now that I have opened my big mouth let me explain.
I hunt deer with a savage 111 in 7rm, it's most accurate (at the range distance that I hunt in), load is 67.0grn IMR7828, cci 250 primer 150 grn etip 10thou off the lands. I load 139's and 175's just for giggles at the range but never adjust the scope I just hold off to hit my mark.
Every time I go to the range no matter what bullet dejour Iam using I always bring 1 of my deer rounds and it is the first out of the tube. And that is how I constantly know where my "cold shot" is. And it always pushes the button.
I hope you understand my thought here, it works for me.

 

[mhamlin]

Clark, I love your method; however, I can't get that much time away from work. I changed jobs last year and don't accrue as much time, as I am used to having. I will be able to sight in at elevation and adjust accordingly.

g0rd0, I'm following your train of thought and it makes perfect sense.

Thanks for the info guys; these are very useful that ideas. I'll try a different approach; when cold-bore mapping, do you still follow conventional load development methods and find the best groups, ES, and SD, before doing the cold-bore work, or do groups not matter at all when developing a hunting round, just ES and SD...? with my old Shooting Chrony, I could get good groups and still not have ideal ES & SD and the converse could also be "true." I just bought a Magneto Speed, but have only used it twice and my ES and SD are reading better than what I got with the old chrony.

 

[MudRunner2005]

Here's my opinion on it...

When most people refer to "hunting accuracy" they are making excuses for a poor-shooting group or rifle (group that fits inside the vitals area) that is "good enough" for killing a deer at their max desired yardage, or they're too lazy to further their load development.

The way I see it, target shooting is one thing, and hunting is another. BUT, they should both be precision in their own right. Target shooting is more precision because you are striving to beat yourself, or someone else's group, therefore extreme precision is the name of the game.

However, hunting should also be something you strive for the most precision possible. Shot-placement is key when taking game animals humanely. If you want the most humane way to dispatch an animal, you want the cleanest kill possible, therefore you want the most precision bullet placement your rifle can produce. Which means, the only thing that should be considered "hunting accuracy" should be anthing LESS than 1 MOA, if you plan on shooting more than 300 and up to 500 yards. Because 1 MOA is roughly 1" at 100 yards, and multiplies from there (1 MOA @ 200 yards = 2"). If you're shooting beyond 500 yards, 1/2 MOA or better should be the name of the game.

Therefore, there should be no "hunting accuracy" or "target accuracy". They should both just be one in the same, striving for the most accuracy possible out of your weapon and load.

I won't hunt with a rifle that shoots more than 1 MOA... If a rifle shoots more than 1 MOA, I rebarrel it. It HAS to be sub-MOA for me to hunt with it inside of 500 yards...And if I'm shooting beyond 500 yards, it has to be 1/2 MOA, or better.

 

[kbaerg]

I have to agree with mudrunner on this. When I setup a rifle and develop a load I will work and tweak until I achieve half MOA or better (I strive for better than half). Kind of along the lines of aim small miss small.

 

[barefooter56]

Mikecr and others posted on the topic elsewhere on the site, but I stiil have question(s). I've been chasing speed and the perfect group size with my new rifle. I seem to only achieve one, or the other, at a time.

Mikecr's point has finally sunk into my thick skull. All of the animals I've killed were first shot hits, so why have I been using up the short barrel life of my 300 RUM...?

I read the Carlos Hathcock method of cold-bore accuracy and see how it will better suit my needs. I think my question is: do I only test for the lowest ES & SD at a given bullet/charge combination, or am I missing some other important detail.

Thanks, Mike

mhamlin,
Lowest SD and test at range you will be shooting at. SD is a great indicator of the vertical dispersion of the load . In short you want a "flat" group . Try to get the SD to 10 or below and test. Get a good "no -wind" zero. figure your come-ups to other ranges you may encounter from your zero range. Learn how to read conditions (wind/mirage)= practice.

 

[rpierce]

Forget speed up to a certain extent. That extra 50-75 fps means nothing if it won't hit consistently in the same spot. Ballistic programs will compensate for your slower load. One extra click is nothing. I apply my fclass loading practices to my hunting rifles. Ladder test then seating depth test. Sort bullets according to weight and use Sartorious scale to measure powder. I will easily have a .3 moa or better load in under 60 rounds for cartidges Ive loaded for before.

Ryan Pierce
Piercision Rifles
www.piercisionrifles.com

 

[Mikecr]

I disagree with MudRunner. For one, precision and accuracy are different, separate,, nothing in common.
I also disagree with suggestions of averaging results for 'statistical probabilities'.
None of this funny math will help in single shot kills, and is inappropriate to rely on for LR hunting shots.

I see common understandings as analogous to the bullet sorting folks are tail chasing with. Where they don't understand what measurements mean, they're as likely tossing the best bullets & keeping the worst! It's the same with barrels, brass, and shooting results.
Add to this, the placebo in spending more or adding efforts(regardless of function) -for intent, rather than actual results. It's very hard for many to see that $2pc brass, and a $250 trigger didn't actually help a NightForce scope issue. How much money will they spend and never nail that weakness while averaging of shooting results(ala 20sht hot grouping)?
I don't average, would never have found it if I did. But I still ****ed time & money concluding that scope issue(which NF fixed for free in 2-day turnaround)...

It's a good idea to develop with distant ladder, and finer hot group tweaking to begin. But moving on to cold bore ACCURACY testing, you're as likely to see things open to nearly 1MOA. And if a varmint hunter, you need to know this sucks completely. It's gonna take a lot of work, load tweaking, and problem solving in seemingly extreme slow motion, to get 1/2MOA to the goal distance. It's not more shooting, it's less shooting-more thinking. Brutal objective thinking.

A drill I run with any hunting gun(I keep): 1" dot at 200yds, pull gun from the safe, install Harris bipod, drive to the range, set gun in dirt & put one cold shot in that dot. 2hrs later, put another in the dot. Do it again at 1hr, 30min, 10min. That's a 5sht group, could be an ugly ~.9 IPHY group, but all that matters is you hit that dot -every shot. That's 1/2 IPHY of accuracy at 200yds.
If you can't pull it off, and most would find they can't to begin, figure out why. Don't waste energy further out,, don't play around walking shots into metal a mile away.. Figure out why your accuracy is broken.

 

[Clark]

I can drive an hour to a 100 yard range and get accuracy [close to the bullseye] and I can get precision [small groups], but I am having a terrible time when I drive 900 miles and shoot long range.

It is the bullet trajectory and wind drift that are killing me.
I can build a rifle that shoots 0.2 moa. I have done that in 6mmBR with a short fat select match bull barrel.

But when I set up the target at long range, most of my guns cannot keep it in the 10" kill zone at 500 yards, which would be 2.0 moa, ten times less precision.

The 7mmRemMag loaded at 75 kpsi with boat tail bullets, and shot at sunrise when there is the least wind, will typically keep all the holes in the 10" ring at 500 yards. Last year I had a rifle that would keep in the kill zone at 550 yards, and it was a factory rifle.

The average wind speed in the USA is 7.4 mph.
That will make the average bullet drift 12" at 400 yards and 48" at 800 yards. [the further away, the smaller the target is a linear problem. The further way the wind drift increases as the square. That is exponential trouble.]

A typical bullet will drop 24" at 400 yards and 160" at 800 yards.

Even though trajectory is twice as much, the wind is giving me more trouble than the trajectory, as I can figure out the trajectory, and compensate with my elevation turret. I hold up my Kestrel and measure the wind, look for the mirage at different distances by playing with scope focus and make a guess.

 

[FEENIX]

For what it is worth, last year's hunting season ... ... last cold bore shot at 200 yards before calling it good for the general rifle hunting season (.270 AI 175 Matrix VLD).

... yielded a young muley buck at 311 yards.

 

[kbaerg]

The part I agree with was that hunting and target should be the same, BOTH accuracy and presicion. My fault for not clarifying that. .

 

[Mikecr]

The part I agree with was that hunting and target should be the same, BOTH accuracy and presicion.

There is no reason it would turn out this way. It does here & there, and it doesn't here & there..

Let me give you a different kind of example, pic below:
A turn-key competition gun, new Tubb2000 in 6XC, 32xNF NXS, right after initial seating testing.
I never held a concern about the gun's grouping potential, but I wanted to find out quick if it had any hunting potential.
Well, this test dashed any hopes for hunting.

Notice the top circled shots at 10min each -horrible -walking all over.
Notice that all fast follow-up shots are better behaved.
I fully developed a hot load to 600yds, and with that I could easily put 100shts into a 1" bull at 200yds. But that's nothing. Cold bore shooting with it didn't improve, as I can't stop walking with load development, and I couldn't change the base design..
So it was a competition gun, made for precision, and I sold it off with an excellent load just for that.

I sold it because it didn't have the hunting shot potential I was hoping for when I ordered it.
Really don't know what I was thinking,, but I did learn a bunch with the gun in several areas, and made a little profit in the end.

Anyway this is a good example of cool to warm, right together. With a warmed up condition, I had precision. Otherwise, I had nothing. This being a free floated tube gun, the shifting is amplified over a well bedded stocked gun. But I've also seen the issue to lesser degree with a competitive glue-in 6ppc. Some of it is the button rifled barrel stresses, some because bores aren't drilled perfectly straight. Traces of cleaning residue,, stress in scope mounting,, any thermal shifting.