Found the load.

[Rule 243]

After many trips to the range which is 2 hours round trip I finally found the load I was looking for.
The rifle is a custom built 243 Ackley Improved, 26 inch Shilen stainless select match barrel, Remington 700 SA that's been blueprinted, MDT XRS chassis so I knew the rifle should be a shooter.
I loaded up 3 rounds each of different powder charges of IMR 4831, they were 43grs, 43.5grs and 44grs. The rounds were topped off with Barnes 105 grain match burners.
The group's were 43grs 0.450 inch, 43.5grs 0.370 inch, 44grs 0.290 inch, all groups were shot at 100 yards, life is good.

Best Regards to all and have a Happy and Safe 4th of July.

 

[dannyjbiggs]

Life will be even better for you if you now go out and test that load at 200 yards with a 10-shot group! . Three shot groups don't show much, IMO?

 

[Sandstorm]

Now take the 44gr load and test a few increments in seating both ways...
you may find something more...Ps..whats the speed...?
just my2c
Nice shooting by the way.

 

[Ned Ludd]

IMO - 10-shot groups are a thing of the past. They were great before anyone had to use an automated pay service to even find trace quantities of powder/primers/bullets/brass in stock anywhere, and even then the items often manage to disappear before you can complete checkout.

3-shot groups are the new "normal"...they tell you just enough information, and you can do 3.33X more of them for the same amount of reloading components. LOL

 

[Sandstorm]

I dont need more than 3 shots...either.
Right you are Ned

 

[joshb]

IMO - 10-shot groups are a thing of the past. They were great before anyone had to use an automated pay service to even find trace quantities of powder/primers/bullets/brass in stock anywhere, and even then the items often manage to disappear before you can complete checkout.

3-shot groups are the new "normal"...they tell you just enough information, and you do do 3.33X more of them for the same amount of reloading components. LOL

Pretty soon we might see a new shooting competition. One cold bore shot per target. 100-500. 5 shots total!

 

[Homerange]

Pretty soon we might see a new shooting competition. One cold bore shot per target. 100-500. 5 shots total!

That's just called real hunting.
Comps like this for the shot gunners are called simulated field and they been doing this for decades.

 

[jepp2]

3-shot groups are the new "normal"...they tell you just enough information

The only thing I have confidence in that a 3 shot group tells me, is if a load WILL NOT shoot. I'll post a target and I have zero confidence that the group size on the target is repeatable. Kind of like 3 shots giving meaningful ES and SD. Just call me skeptical.

 

[Sandstorm]

That's just called real hunting

Now we have a name for our one shot at a 1000 yd competition. ( Real Hunting Class )

 

[Sandstorm]

group size on the target is repeatable

Unless it does repeat...but it will take more shots.
I find some combinations for me have been great indicators or repeat-ability..after just 3 shots.

 

[Bill Norris]

What will a 10-shot group tell me that 3 or 4 3-shot groups on the same target all shot together won't IF when transposed one on top of the other the 3-shot groups over-all are not larger than the 1 10-shot group. After all, the rifle and load are being fired 10 or 12 shots anyway at the same range session.

 

[PigButtons]

At least I know that if after three shots it does NOT group, it won't get better if I shoot 10. So why not start at three and save all of those materials and effort.

 

[Homerange]

At least I know that if after three shots it does NOT group, it won't get better if I shoot 10. So why not start at three and save all of those materials and effort.

Yep 3's enough when you know you can shoot.
Some of course can't even to save themselves and need 10 so if there's some missing they just come out with the BS there's some through the same hole.

Like the chap that was here last week to give his long neglected and itchy trigger finger a damn good scratching firing a # of 303 SMLE's that he's started collecting. 127 rnds of new Winchester factory loads later my brass bin looked pretty good and the whole lot was rescued for a mate that shoots mil comps.

 

[Jager]

Regarding the number of shots needed to evaluate a load, perhaps this is helpful...




These two charts are courtesy of Bryan Litz, Modern Advancements in Long Range Shooting, Volume II (highly recommended). (https://www.amazon.com/Modern-Advan...swatch_0?_encoding=UTF8&qid=1625310057&sr=1-4).

I shoot more 3-shot groups than anything. As mentioned up-thread, it doesn't take any more shots than that to determine if a load doesn't work. And multiple 3-shot groups, printing to the same POI, will provide the statistical confirmation that that first group was whispering the truth. Or not.

Congrats to the OP on having a rifle that shoots.

 

[JEFFPPC]

I do quite well with 90 percent of my testing with 2 shot groups. I no longer try to promote it, I just go and win while hearing how many shooters wear their barrels out with non productive extended testing. Me, I enjoy competition. Maybe those extended group sessions really are showing problems with the shooter not the load.

 

[Rule 243]

First I appreciate everyones opinion and thoughts, thank you.
As for shooting more groups to find one that may be a little better is not needed as I do not shoot any kind of formal competition.
When I had my own range at my place and components were easier to get yes I enjoyed shooting more groups, it's not so much fun when you have to drive 2 hours round trip to a public range plus finding components.
I will shoot the load at longer ranges, planning a trip to an 800 yard range and I'll be going to my oldest Grandson's to ding an 8 inch plate at 300 and 400 yards.
If the load don't pan out then it will be back to the drawing board.

Best Regards to everyone and have a Happy and Safe 4th of July.

 

[jelenko]

.

What is the variable that goes on the left hand of these tables? E.g., for the 1/4 MOA, under the 3 shot column, what is 'varying' to cause .25, .20, .16, then .14?
Do I have it right that these decimals are the % probability? I.e., .25 = 25% chance?

 

[Bill Norris]

I do quite well with 90 percent of my testing with 2 shot groups. I no longer try to promote it, I just go and win while hearing how many shooters wear their barrels out with non productive extended testing. Me, I enjoy competition. Maybe those extended group sessions really are showing problems with the shooter not the load.

I believe that the 3 shot group is testing the rifle and load while the 10 shot group is testing the shooter.

 

[JFrank]

I like 3 Oyster shooters and a cold beer, 2 just isn't enough while 10 would be like whooo dude....

 

[pirate ammo]

My first shot is always great, it's all the rest that are messed up.