Same group size two different loads what should I load

[bearhunter]

A 100 yard group is not a real good indicator of what will happen at 200 or 300. And a 3 shot group is not statistically valid. A number of 3 shot groups would be more useful.

If it was me, with that problem, I would find a place to shoot 200 or 300 yards and then shot a pair of 5 shot groups. One would look better than the other.

When I was making match ammo, it was tested with 20 shot groups at 500 meters. Here is a 1 .75" grouip

Jim, were you allowing cooling time between each shot or for example a string of five shots, allow to cool and shoot five more??

I fully agree 100 yard groups are only indicative of how well a rifle will shoot a particular load at 100 yards.

For those that want to shoot further out, groups should be tested at incremental ranges, out to the farthest distance a shooter feels confident in making a good hit in the vital zones on the type of game they're hunting.

By shooting at different ranges, say 50 yard increments, after 300 yards they will get "real" information as to how far their bullet drops, when shot from their rifle, with the load they're using.

 

[Dogleg]

For those that want to shoot further out, groups should be tested at incremental ranges, out to the farthest distance a shooter feels confident in making a good hit in the vital zones on the type of game they're hunting.

By shooting at different ranges, say 50 yard increments, after 300 yards they will get "real" information as to how far their bullet drops, when shot from their rifle, with the load they're using.

Or alternately; just go out to the longest range you'd shoot at and see if you have a load or not. If it's going fall apart; who cares what the drops are in between? It's just a waste of ammo and barrel if the load is going to be scrapped anyway. If the say 500 yard (arbitrary number that just happens to easy on my private range) groups deliver, then you can always shoot the shorter distances if you want.

Along that theme; I usually just shoot a pressure sequence at the beginning of load development going up one grain at a time with just a single shot of each. This establishes a working maximum with just a few shots. Why work up a load when you can work down a load? If you do it over a chronograph you will find out in those same few shots if you are getting anywhere near the expected velocities. If you can throw the rifle faster than the bullets are going you can scrap that powder and go back to the drawing board. Who cares how it shoots if you can't live with the velocity?

The pressure sequence can be shot as a ladder for whatever real or imagined info can be gleaned from that.

 

[Potashminer]

Or alternately; just go out to the longest range you'd shoot at and see if you have a load or not. If it's going fall apart; who cares what the drops are in between? It's just a waste of ammo and barrel if the load is going to be scrapped anyway. If the say 500 yard (arbitrary number that just happens to easy on my private range) groups deliver, then you can always shoot the shorter distances if you want.

Along that theme; I usually just shoot a pressure sequence at the beginning of load development going up one grain at a time with just a single shot of each. This establishes a working maximum with just a few shots. Why work up a load when you can work down a load? If you do it over a chronograph you will find out in those same few shots if you are getting anywhere near the expected velocities. If you can throw the rifle faster than the bullets are going you can scrap that powder and go back to the drawing board. Who cares how it shoots if you can't live with the velocity?

The pressure sequence can be shot as a ladder for whatever real or imagined info can be gleaned from that.

This is about what I have been doing, except two shots at each level working up - I have been adding one grain per increment until about 1/2 way, then 0.5 grain per step - often just fired off in a ditch - do not care if they are accurate or not - just how "hot" can I go with that combination of components. As advised here on CGN, I usually go 1.0 grains past what I find as Maximum in various reloading manuals - but working up - step-by-step - from Start load. A Weatherby Mark V in 7mm Weatherby Mag shows nothing different (on the case, or primer, or bolt lift) at a grain past Nosler's Max than it did 2.0 grains below Max. Same with a Ruger 77 in 22-250. Not sure any more which one - 338 Win Mag or 7x57 - bolt lift was "tighter" a full grain below Max - I decided to stop there with that combo. A tight-to-open bolt is NOT what I can tolerate when hunting - I will already be PO'd enough having missed!!!

For hunting loads, I usually want SMACK - so top two or three loads get loaded up with 5 rounds to try for accuracy. Likely different for target score competitions - I had read that Speedy Gonzales did not care how fast his bullet was going, so long as it went through same hole as last one did. For target shooting, I think is much different stuff - can tolerate a snug to close bolt, etc. - but I do not think velocity is really a big thing for most target games? (So long as bullet stays supersonic to target?)

 

[Ganderite]

Jim, were you allowing cooling time between each shot or for example a string of five shots, allow to cool and shoot five more??

I fully agree 100 yard groups are only indicative of how well a rifle will shoot a particular load at 100 yards.

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I didn't test my ammo. Bill Wylde did it for me. he shot the entire 20 shots in one quick go. I doubt the 20 shots took more than a minute. he used a rail gun with a Krieger/Obermyer.

 

[Ganderite]

There are 120 possible 3 shot groups in a single 10 shot group. Thats if you don’t care what order they hit; because if you go down that rabbit-hole there are 720 possible combinations. Don’t do that; its a sure path to madness.

Comparing a single 3 shot group to another (as opposed to comparing 2 10s) is comparing 1 out of 120 to another 1 out of 120. Since I’m on a roll; there is 14,400 possible combinations, so that sort of depends on how lucky you’re feeling.

Or you can get 50/50 odds flipping a coin, and save the shells.

Very well explained. When I worked at the CIL ammo R&D lab, my boss kept shooting down my observations with "Not statically valid." In other words, don't draw a conclusion from a small test.

As shown above, final conclusions were tested with 20 shot groups. Loads were developed with 10 shot groups. I could watch the groups form. Many a fantastic 5-shot group became an ordinary 10 shot group. Any conclusions based on 5 shot groups would have been baseless.

And 3 shot groups even more so.

Two things I have learned:

100 yard groups mean nothing if the ammo is to be shot at longer ranges.

Groups less than 10 shots don't mean much.

 

[bearhunter]

I didn't test my ammo. Bill Wylde did it for me. he shot the entire 20 shots in one quick go. I doubt the 20 shots took more than a minute. he used a rail gun with a Krieger/Obermyer.

Don't get me wrong, but rail guns will give far different results than a bench rest rifle, or especially a hunting rifle with a light, short barrel.

I see where you're coming from and why, but I can't agree that comparing oranges to apples will be anything more than lightly indicative as to how a specific rifle will react to any load.

If it is true that such tests will confirm the accuracy of an off the shelf rig, then those that handload wouldn't have to purchase different brands, with different loads to find one that will shoot acceptably in their rifle.

 

[Fox]

How does 44.5gr look, and 46gr? What about 45.3gr?

You may have 2 loads in an accuracy node, that is good, but if they open up significantly on both ends then consider grabbing right between them at 45.3gr, check that load.

If that load is good then you know if you are shooting in slightly hotter or slightly colder conditions your load probably will not go to crap.

Also though, shoot more than 3rd groups and see what they look like with a 5rd group or more.

 

[fljp2002]

How does 44.5gr look, and 46gr? What about 45.3gr?

You may have 2 loads in an accuracy node, that is good, but if they open up significantly on both ends then consider grabbing right between them at 45.3gr, check that load.

If that load is good then you know if you are shooting in slightly hotter or slightly colder conditions your load probably will not go to crap.

Also though, shoot more than 3rd groups and see what they look like with a 5rd group or more.

Have 5 rounds of 45, 5 of 45.3 and 5 of 45.5 ready for testing today

 

[Lead hammer]

Very well explained. When I worked at the CIL ammo R&D lab, my boss kept shooting down my observations with "Not statically valid." In other words, don't draw a conclusion from a small test.

As shown above, final conclusions were tested with 20 shot groups. Loads were developed with 10 shot groups. I could watch the groups form. Many a fantastic 5-shot group became an ordinary 10 shot group. Any conclusions based on 5 shot groups would have been baseless.

And 3 shot groups even more so.

Two things I have learned:

100 yard groups mean nothing if the ammo is to be shot at longer ranges.

Groups less than 10 shots don't mean much.

Groups less than 10 can certainly get you in the ballpark for further testing to verify at greater distances and with more rounds.
I find my 100 zero usually needs a small seating adjustment at distance to do better at 300+ meters. 3 shot groups, then doing 10 shot groups at distance is just fine. I use OCW and OSD, so it’s not just about group size, but the proximity of the center of each group with its neighbors.

 

[OkayShooter]

Reverse shooting the groups and see if the outcome the same.

I've done load development where I had 4 loads, I shot a group each in succession, then I reversed it and had different outcome

1, 3 groups were the best, then reverse. 4 and 2 were better.

 

[OldDude]

Reverse shooting the groups and see if the outcome the same.

I've done load development where I had 4 loads, I shot a group each in succession, then I reversed it and had different outcome

1, 3 groups were the best, then reverse. 4 and 2 were better.

When I'm testing loads in a rifle, I load one of each test round in a mag, then fire, in order, at a specific aming point for each test. For instance, 40, 40.5 and 41 grains of SuperSpeed MkIX powder, each fired at the top left, top right, and bottom left aiming point on a target. Repeat until 5 rounds of each fired at each target. Keep in mind that a rifle magazine is emptied (fired) last in, first out.

 

[Potashminer]

When I'm testing loads in a rifle, I load one of each test round in a mag, then fire, in order, at a specific aming point for each test. For instance, 40, 40.5 and 41 grains of SuperSpeed MkIX powder, each fired at the top left, top right, and bottom left aiming point on a target. Repeat until 5 rounds of each fired at each target. Keep in mind that a rifle magazine is emptied (fired) last in, first out.

I do similar. I think is called "round robin" - I do not load the mag - just feeding one round into chamber or into magazine at a time. First shot of first load is shot at first target, first shot of second load fired at second target, third at third, etc. Then second shot of first load at first target, second shot of second load at second target and so on. Requires you to re-set / re-align on sandbags for each shot - but seems to "average out" a bunch of things - wind, light, barrel fouling, etc.

 

[fljp2002]

Was out today and shoot 5 round group at 220 yards

The 5 rd group with 45.5 of H4350 was 0.72 MOA and the winner was 5 rd group with 45 gr of H4350 for a group size of 0.66 MOA

I could load either but prefer to go with 45 gr for less pressure.

IMG_0544 by fljp, on Flickr

 

[Lead hammer]

I bet you could do a small seating depth change and get it tighter but the coyotes should be nervous regardless. Make sure to post results on the coyotes.

 

[fljp2002]

I bet you could do a small seating depth change and get it tighter but the coyotes should be nervous regardless. Make sure to post results on the coyotes.

I would need a micrometer seating die to get into that game. Plus the COL with the 95gr vmax is barely 2.67 and 6.5 creed can be as a long as 2.825. Since I won’t reach the lands not sure if it will make a significant difference

 

[Mystic Precision]

Just go enjoy the rifle and load.... it is shooting well.

Jerry

 

[Lead hammer]

I would need a micrometer seating die to get into that game. Plus the COL with the 95gr vmax is barely 2.67 and 6.5 creed can be as a long as 2.825. Since I won’t reach the lands not sure if it will make a significant difference

You could get creative with your die and a sharpie, but ya you are good to go for the dogs.

 

[BearClan]

Listen to episode 99 of the Hornady podcast (topic is “mean radius”) and then (a) download Hornady’s 4DOF and purchase the “group analysis” feature (about 6ish $s) or (b) if you are competent in MS Excel, you can calculate the “mean radius” yourself. Your very scenario of deciding between loads producing groups with similar/equal extreme spreads is exactly the scenario where using Mean Radius comes in handy.

 

[Janeau]

Listen to episode 99 of the Hornady podcast (topic is “mean radius”) and then (a) download Hornady’s 4DOF and purchase the “group analysis” feature (about 6ish $s) or (b) if you are competent in MS Excel, you can calculate the “mean radius” yourself. Your very scenario of deciding between loads producing groups with similar/equal extreme spreads is exactly the scenario where using Mean Radius comes in handy.

Yes itbis true..but is it needed for a hunting load ?
Both are more than good enough. OP, just go hunt..stop burning components on paper

 

[Canuck65]

Whatever’s cheaper and easier to find.