shot conformation

[sendero72]

What are you looking for in your loads, hunting? I have a way I have worked around that with testing.

I only use match bullets for hunting, even though the box says "not for hunting". I weigh my bullets, cases, and weigh the powder down to the kernel. I practice year-round and shoot a tall target test at 600 yds vs the lab-radar. Then I move out to 700, 800,900, and 1200 yds. My gunsmith knows that if the rifle doesn't shoot under 1/10, then we have a problem. My current 7x300 win mag shoots .07 at 100 yds. This is barrel number five and I average 1244 rds per barrel. Always keep good notes. I have a book on every round loaded since 1999. My goal this season is to kill a deer at 1200 yds plus. Good luck and have fun out there!

 

[crkckr]

Please note this is how I do it and involves my opinions only. Take it for what it's worth.

Let's say that I'm starting out with a new big game hunting rifle and no idea how it will handle my hand loads.
I will decide which Nosler Partition bullet will probably fit my needs the best because I don't hunt big game with anything else. Using a bullet of equal weight (but not the cost!) I will try several different powders that are the most likely to give me the highest velocity I can get. Once max velocity is established (using a chrono), I will load up 3 round batches of the good stuff (read = $$$) with the Partitions and the different powders and shoot these off the bench at 100 yards.

Ok, a little pause here. I am at a big advantage over most guys in that my 100y range is in my back yard. My chrono is usually set up right outside my basement sliding glass door, literally 20' from my loading bench. Of course it makes the entire process a whole lot easier for me. But then, I planned it that way.

So, 3 round groups. Anything that looks like it has potential will get further load development, maybe drop the charge by 0.2 gr and see if there is any improvement. If yes, drop a couple more tenths and check again. Vary the seating depth a bit (always seating deeper because I always start out at max magazine length).

If I can't find a load that shoots well with this set up, I might try some other powders but if I don't see any potential, I sell the rifle (which I have only had to do a couple of times, just because they didn't like the Partitions... it happens). If I can get a nice group out of the rifle, I will try a 5 shot group. If things go well, I will clean the rifle down to bare metal, fire 4 or five foulers (back to the cheap bullets for this task) then run a patch of synthetic oil thru the bore, just as I always do if not cleaning the bore, such as when hunting. While I've never taped my barrels, it's a very good idea and today I would do this.

Now I wait for whatever conditions I expect I'll be hunting in. Living in the State of Misery (MO - it really isn't quite that bad but almost!), you'll get just about everything eventually. I'll put the rifle (in it's case) in the garage overnight, along with the ammo, and when conditions are as bad as I think they'll get, I go out and shoot a cold bore shot. Target is brought in and marked and the barrel gets one pass with some oil on a patch (not soaked and dripping, just damp). Then it's a matter of waiting at least a couple of hours and if conditions remain the same, shoot another round. I do this a third time so I can hopefully eliminate any loose trigger finger screwups. If the group is still centered where I want, oh happy day we're almost done! If not, adjustments must be made and cross checked (conditions seldom last long enough to do this in one day here, as the weather changes quickly and often dramatically... and somehow, it always seems to get worse!). Once all that is done, then I'll try (again in the same conditions if possible) a two or 3 shot group, just to make sure everything stays in an actual group, instead of playing "shotgun!" I will also test in other conditions, of course, although with my luck, shooting in the worst conditions usually matches what actually happens! I also use a ballistics computer to set up a point blank range chart - *based on the velocity and accuracy of that particular round!*

If you set up your AR or any other rifle to shoot at some phantom point blank range (36 yards is the most often quoted for the AR), you're doing it wrong! Without knowing the actual velocity of the ammo you're using that 36 yard target is mostly a guesstimation! There are numerous point blank range calculators online but like anything else, garbage in, garbage out!

So even with my range being close at hand this process can take time, which being retired I have lots of! I know the average hunter probably won't take this much time to get his/her rifle dialed in but in the long run, it can make for some serious confidence when you're up to your knees in snow, laying down in it and shooting that big bull or buck and knowing that your bullet is going exactly where you want it to go and that it will it's job perfectly when it gets there. And I like that!

I always do my best to get as close as I can to a big game animal and admittedly, the majority of my shots are pretty close. While I never plan on taking the longest range shot I can find, I like to have the ability to do so if necessary, so I practice that, too. So far the longest shot I've ever taken on a game animal is 700 yards, totally unplanned and unprepared for (someone elses wounded antelope... it's a really long story I won't bore you with! Aren't you glad?!). Please note, jack rabbits are not big game animals! Oh the stories....!!!
Cheers,
crkckr

 

[LRNut]

Single shot testing is largely a waste of time because a single shot tells you next to nothing. There's no situation in which a sample size of 1 gives you any meaningful information about a larger group. You have no way of knowing where that sample falls in the expected spread you'll see over the whole group. Shooting more rounds gives you a rough idea of what that spread will look like. Shooting high round count groups or aggregating multiple low round count groups gives you a pretty accurate picture of what you'll see over many rounds.

It's a stochastic system, not a stable system. The best we can do is use statistical analysis to predict the region in which a shot will land. Doing so requires a large enough sample size to create an accurate estimate. The required sample size depends on what level of confidence is desired. For precision rifles I strive to capture the 1 in 20 outliers, but don't worry too much about the 1 in 300 outliers. That comes late in the load development process. In the early stages lower round count groups can eliminate bad loads and point you towards good loads. A single round does neither.

This is one of the best posts I have seen. I make my living off our statistical software and I am often frustrated by shooters who make claims such as "I never fire five shots at big game, so a three shot group is good enough." Or, you share with us how you shot an antelope at 800+ yards in a 15 mph wind - you are not going to do that ten times in ten years so it doesn't mean you can do it every time. Just yesterday, a so-so pitcher pitched the 24th perfect game in MLB history - but no one has ever done it twice - meaning a healthy dose of luck is involved.

On the other hand, one shot does tell you quite a bit, but only when viewed in conjunction with the one shot you took the day before, and the day before that, etc. - what most call "cold bore." When I shoot at gongs, I rarely take a second shot because the first gives a huge amount of feedback and correcting from that is easy unless the wind is gusting hard and switching directions - like it did yesterday at my CO place. Not good for the ego.

As long as I am being so professorial, I would point out that conformation and confirmation have two different meanings.

 

[biednick]

On the other hand, one shot does tell you quite a bit, but only when viewed in conjunction with the one shot you took the day before, and the day before that, etc. - what most call "cold bore."

I definitely agree with this point. I don't view that as single shot testing though. You're still shooting multiple rounds and looking at overall trends rather than the performance of a single shot.

 

[LRNut]

I only use match bullets for hunting, even though the box says "not for hunting". I weigh my bullets, cases, and weigh the powder down to the kernel. I practice year-round and shoot a tall target test at 600 yds vs the lab-radar. Then I move out to 700, 800,900, and 1200 yds. My gunsmith knows that if the rifle doesn't shoot under 1/10, then we have a problem. My current 7x300 win mag shoots .07 at 100 yds. This is barrel number five and I average 1244 rds per barrel. Always keep good notes. I have a book on every round loaded since 1999. My goal this season is to kill a deer at 1200 yds plus. Good luck and have fun out there!

Next time I am NC can we make a $1000 bet that you can shoot 3 5 shot groups that average .07"? The only caveat is if you win, you name your gunsmith so I can use him. It would be worth $1000.

 

[LRNut]

I definitely agree with this point. I don't view that as single shot testing though. You're still shooting multiple rounds and looking at overall trends rather than the performance of a single shot.

Exactly

 

[Fatcatbuster]

The only time I shoot single shot ladders is to find pressure. Sometimes it can give you some idea of potential nodes if velocity is somewhat flat between different loads. With the price of components being high, I usually start with 3 shot groups just below pressure to see if my velocity spread is reasonable. It will give me an indication at this point whether the bullet powder combination is worth pursuing. My rifles are for hunting and having fun at the range. 1/2 MOA is what I am striving for over 5 shots in multiple sessions in stable wind.

Pressure first here too. Looking for bolt lift and case contition. Then start the hunt for accuracy eliminating obvious directions. 3 shot groups looking for improvements with powder charge compared to grouping's,I usually find more powder means tighter groups.

 

[Calvin45]

With those skinny barrel rifles I take a shot and a followup shot then let the barrel cool. If I can do that numerous times with sub moa results I'm leaving it alone and test again before a hunt. If I can't take the animal out in 2 shots I need more practice.

Bingo.

I have an old savage 99 in .243 with a wispy thin barrel. Shooting conventional 3-5 shot target groups is not the answer if you want realistic info on this rifle's ability in the field.

 

[blvette75]

It's SINGLE SHOT testing.
Eventually, each single shot defines your actual capability.
That said;

I shoot followups very early, to see if the gun has any potential.
Then I focus purely on single shot accuracy.

There are are guns that cannot hold a 2nd shot with the first cold bore shot.
My last with this issue was a new Tubb T2K (tube gun in 6XC), which I had bought for hunting.
While it did what it was designed for (tight 600yd grouping) very well, I could tell right off that it had zero potential for LR hunting shots.
So I had fun with the gun for a bit & sold it off.

This is really the test that told me all I needed to know:
View attachment 472962
For my cold bore testing, I begin at 200yds and 10min shot rate. This is because it's the worst performing condition I am aware of.
That is, when it shoots good under this condition, it will shoot better under any other.
Anyway, the high spread shots were 10min each, with an immediate followup that formed a group along the target edge.
This was not the best cold bore load, and the brass was new/unfired, but it doesn't matter because the followup shots told me all I needed for this test (which is why I do it). A good test to do while fire forming brass.

A stable system, at 200yds, would put each in a 2sht group at least touching.
A good cold bore load would put them all inside that target.
I could develop with this gun to putting fully cold bore inside the target, but I would forever know that a followup would depart.
So given varying field conditions, i could never really know that my 1st shot could be relied on either.
No amount of load development can fix this, so you can save a lot of tail chasing right here. It passes the test, or fails.

Thanks for the post saved me the trouble on the Tubbs gun.

 

[blvette75]

I definitely agree with this point. I don't view that as single shot testing though. You're still shooting multiple rounds and looking at overall trends rather than the performance of a single shot.

I agree as once I have my round established with a rifle setup, I will confirm the cold shot accuracy annually typically with a single shot, there is never any variance the round is always about 1.6" high at 100 yards. I do not see drift at all year to year. Even with ammo loaded 20 plus years earlier that were recently found that were miss placed when I moved here, still got the same result.

 

[Shootin4fun]

This is in consideration for hunting- After I find a stable powder node I find a seating depth node; one that groups well shooting 5 shot strings, allowing the barrel to cool after each 2nd shot. I record the POI of each shot. This gives me an idea of first shot POI, 2nd shot POI (which I can depend on for hunting) and also overall grouping. I rarely fire five shots in a row without letting the barrel cool. I don't shoot matches, so I have no real world demand for shooting high count strings, and my thought is that I am extending barrel life by rarely shooting with the barrel, sizzling hot. If I were shooting matches or prairie dogs, and I would be more concerned about high round account/hot barrel accuracy.

 

[LRNut]

Bingo.

I have an old savage 99 in .243 with a wispy thin barrel. Shooting conventional 3-5 shot target groups is not the answer if you want realistic info on this rifle's ability in the field.

Ok, so shoot 10 shots over 10 days and measure the group. That will tell you a lot more than three 3 shot groups.

 

[Shootin4fun]

I agree as once I have my round established with a rifle setup, I will confirm the cold shot accuracy annually typically with a single shot, there is never any variance the round is always about 1.6" high at 100 yards. I do not see drift at all year to year. Even with ammo loaded 20 plus years earlier that were recently found that were miss placed when I moved here, still got the same result.

Exactly. Except after the first shot hits exactly where expected, I always want to send another to see if it goes in the same hole. And then maybe a third. If there is drift in the third, I call it good anyway and move on to just having fun. Otherwise my trip to the range would be very short. When I have a combo that works every (or most of the) time, sometimes I laugh to myself and think "this gun is boringly accurate".

 

[Calvin45]

Ok, so shoot 10 shots over 10 days and measure the group. That will tell you a lot more than three 3 shot groups.

Agreed. I do still shoot groups but it's hard to wait haha (patience isn't my strong suit and I don't get to go out shooting half as much as I'd like…but all I'm saying is once that barrel gets hot there's little useful info to be had. No need to shoot ten shots over ten days tho haha.

And I will say I'm convinced that the first shot is obviously the most important one, and that's not just when you're hunting. If everything "felt right" on round one shooting at targets and I hit where I meant to I don't worry about it much if subsequent shots cast doubt…