Found the load.

[Northridge]

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

though I do agree in regard to systems braking down on broader strings of fire, may it be shooter fatigue or bag set up changing this is legitimate. heat soak on a given barrel can and does change or push a rifle out of or even in to tune. depending on the location of your tune this can be very favorable or damaging over a long string of fire even a short string can call for a slight alteration in premium results. I find often when a gun is finicky or naughty people find comfort somehow in saying well "I" pulled a shot or condition got me. A rifle simply out of tune will kick shots, a rifle riding the ragged edge and tuned around a short string will kick shots as you push on with additional barrel soak. though so many things will affect the end result believe all aspects play a roll in reaching the finish line and we all will develop personal bests of that I am sure.

Shawn Williams


though I am likely the weakest link in the chain a rifle that truly is willing to "HUM" will make everything seem effortless..

 

[Rule 243]

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.

I need to do more chronograph testing and will, preliminary test showed 3045 fps.

 

[ParallaxFree]

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.

What an interesting reply, which makes a LOT of sense if you really think about it, particularly with early load development. However, your reply touched on something else that I was thinking as I read the responses to the OP.

10 shot groups are great for statistical analysis, but a very poor idea for a barrel burner. Largely because of it's short neck and subsequent flame throwing characteristics on the throat, the 243 Win has a well deserved reputation for being hard on barrels. Now, improve the case and hot rod it and you're definitely in the burner category. It's one thing if you're dealing with wringing the last little bit out of a 30BR and another altogether with a hot rod cartridge.

 

[JEFFPPC]

I find it interesting you said statistical analysis. I was first talked into 2 shot groups by a friend who is a statistical engineer in industry. I was very sceptical. I learned pretty quickly he was correct. Pretty simple, if the first two don't go in the SAME hole, move on. If they do, try it again. If it repeats I shoot a 4 shot group. If its in the low ones or in the zeros, load and shoot a match. You need to ddevelop a systematic approach with your 2 shot groups.If your headed to the range with multiple powders, bullets, seating depths at the same time..........your not looking at success. Your just hoping to get lucky.

 

[Ccrider]

My two cents: at 100 yards with a gun capable of shooting 0s, as you get close to tune, two shots will not tell you much. This is my first foray with two shot groups. 6ppc at 100 yards. I thought it pretty useless:

 

[JEFFPPC]

If they are all the same load, you don't say, A1 was fine but but did not repeat .After C I would move on. D and E were wasted shots. If it's different loads see if A repeats. Only valid if your shooting over flags of course. It's not hard. If you don't have an open mind you will not learn. So in 6 shots you learn it's not what your looking for. If you shot 5 - 5 shot groups that's 25 rounds to learn the same thing. I would rather same those 19 shots as good barrel life for a match. If you don't shoot a lot of matches it might not be as important to you.

 

[pirate ammo]

My two cents: at 100 yards with a gun capable of shooting 0s, as you get close to tune, two shots will not tell you much. This is my first foray with two shot groups. 6ppc at 100 yards. I thought it pretty useless:
View attachment 1264714

The way I shoot they all look great.

 

[Ccrider]

If they are all the same load, you don't say, A1 was fine but but did not repeat .After C I would move on. D and E were wasted shots. If it's different loads see if A repeats. Only valid if your shooting over flags of course. It's not hard. If you don't have an open mind you will not learn. So in 6 shots you learn it's not what your looking for. If you shot 5 - 5 shot groups that's 25 rounds to learn the same thing. I would rather same those 19 shots as good barrel life for a match. If you don't shoot a lot of matches it might not be as important to you.

I did not give enough info. The shot below D on row 2 was used the first shot used to dial in this new barrel. A was a fouler. B-E were two shots each with the same load increasing the seating depth at .003 increments. All over flags. No holding. All the groups were under .2. D and E zeros. Not much help.

 

[Kracken McGraw]

After reading this thread getting portable to load at the range makes a lot of sense to save components.

 

[JEFFPPC]

Well, maybe some thing to learn. Looks like as your coming out of the lands several things are happening......all good. Group is getting smaller, vertical is going away, and group is getting rounder. I would have kept going to see if it got smaller or started getting larger again. Ok, now if d & e are both under 1 and they get bigger if you keep going I would take d& e and try .1 powder higher and lower with each.I would then take the best and shoot a 4 shot group, now if 1 have a four shot group around a flat 1 I am ready to go one of a couple of directions. Shoot a second 4 shot if you want to verify, take it to a match and try it. Or if the 4 shot group is small but not round I would see if a TINY bump on the tuner either direction will round it up. It often does. Actually since you shot over flags and it looks like you and your equipment are capable, I feel there is a lot to learn from your target. You know if you were shooting good shots. Trust yourself and your gun....But be honest about it all....don't make excuses. I hope your shooting season is going well.

 

[Jager]

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?

I believe what Bryan is trying to present here is the expected group size when the shot count is either increased or decreased.

Reprinting the chart...


Looking at the first (1/4 MOA) group...

If a given load gives you a 0.25" group with three shots, you should expect a 0.32" group if you take it up to 5 shots; a 0.40" group if you take it up to 10 shots; and a 0.46" group if you take it up to 20 shots.

If you've got a load that gives you 0.25" with five shots, you should expect a 0.20" group if you take it down to 3 shots; a 0.31" group if you take it up to 10 shots; and a 0.36" group if you take it up to 20 shots.

And so on.

Bill's comment on three shots testing the rifle while ten shots tests the shooter is rather on point. We've all been there... you send a couple or three rounds downrange and they're all in the same ragged hole. But then the next one prints a half inch out. F*ck. Did I jack the trigger press? Did I press an extra half-ounce on my cheek weld? Was my position in the bags a half-inch different when I re-built after coming out of recoil from the previous shot? Did my rifle pick up 7-degrees of cant that I didn't catch? Or any of the million other things that can screw up a shot.

Or was it the load, finally coughing up some honesty?

If Bryan's chart has one weakness, it's that it assumes perfect shooting. In the real world, of course, the farther we march to the right the more likely the numbers will blow up simply because of shooter error. Shooter fatigue is a very real thing and the longer the string the more likely we're going to see it color the question does this load shoot?

I didn't laugh when Jeff said he does development with 2-shot groups. Because in the beginning we're mostly trying to find out what doesn't work. And it doesn't require many shots to see that.

What's left, the small pool of candidates that remain, the ones that showed promise, will inevitably get loaded up again in subsequent rounds of testing. The statistics gods will, indeed, get their pound of flesh.

Just not today.

 

[JEFFPPC]

Jaeger, your correct. I just never thought of it that way. I want to get rid of what shows no promise right now. Then massage what shows promise to the best result I can. Thanks for the insight. All I can say is it works very well for me with minimal component expenditure. Yes, the barrel is just another component.

 

[INTJ]

though I do agree in regard to systems braking down on broader strings of fire, may it be shooter fatigue or bag set up changing this is legitimate. heat soak on a given barrel can and does change or push a rifle out of or even in to tune. depending on the location of your tune this can be very favorable or damaging over a long string of fire even a short string can call for a slight alteration in premium results. I find often when a gun is finicky or naughty people find comfort somehow in saying well "I" pulled a shot or condition got me. A rifle simply out of tune will kick shots, a rifle riding the ragged edge and tuned around a short string will kick shots as you push on with additional barrel soak. though so many things will affect the end result believe all aspects play a roll in reaching the finish line and we all will develop personal bests of that I am sure.

Shawn Williams


though I am likely the weakest link in the chain a rifle that truly is willing to "HUM" will make everything seem effortless..

This is 1000% correct. I have never understood when people say "the gun shoots" better than I do or "I pulled that shot" when shooting from a bench with stable rests. There is certain amount of natural variation in group size that will occur even with a railgun shot in a tunnel with BR prepped ammo.

Those of us that compete for group size know this well, and is why we usually are dismissive of claims that such and such big game hunting rifle will shoot 1/4 MOA all day long. A friend of mine has a standing $100 reward out for anyone that will go to the range with him with their non-competition rifle and shoot three 1/4 MOA groups in a row.

That's not to say we don't ever make mistakes when shooting from a bench. There is often a tiny bit of movement even with heavy BR rifles and light triggers, and when we move to lighter weight rifles and heavier triggers that movement increases. However, inside of 300 yds in decent conditions, two shots into 1/2 MOA and a third that opens the group up to 1.5 MOA isn't likely a bench shooting mistake, it's probably just not a good load and more tuning is needed.

Now when shooting in any position other than from a bench or from prone with stable rests, we indeed can make 1 MOA or greater aiming errors. To me that is why load development should be done with good front and rear rests from the bench (or prone if you like to grovel on your belly).

With that in mind......

At 100-300 yds I use three-shot groups for hunting rifles, and need to see either a sequence of "pretty good-good-pretty good" or have a load repeat on different days before I am done tuning. And the ES should be under 25, preferable under 20.

With LR BR rifles, I use five-shot groups at 300 yds for initial tuning. If I had a nickel for every time I had four in one hole with the fifth opening up. The ES should be in the teens, preferable single digit (which I usually get). I will indeed burn through a lot of rounds in initial load development, and I don't care. There is a lot of value in spending that much time behind the trigger and I have my own lathe.....

Final tuning is done at 1000 yds using the round robin ladder test. No chronograph. I was very skeptical of that method, but I have come to think it's the best way. The max distance I can shoot locally is 385 yds, and I am not sure if that is far enough to a round robin ladder test.

 

[jelenko]

I believe what Bryan is trying to present here is the expected group size when the shot count is either increased or decreased.

Reprinting the chart...

View attachment 1264747
Looking at the first (1/4 MOA) group...

If a given load gives you a 0.25" group with three shots, you should expect a 0.32" group if you take it up to 5 shots; a 0.40" group if you take it up to 10 shots; and a 0.46" group if you take it up to 20 shots.

If you've got a load that gives you 0.25" with five shots, you should expect a 0.20" group if you take it down to 3 shots; a 0.31" group if you take it up to 10 shots; and a 0.36" group if you take it up to 20 shots.

And so on.

Bill's comment on three shots testing the rifle while ten shots tests the shooter is rather on point. We've all been there... you send a couple or three rounds downrange and they're all in the same ragged hole. But then the next one prints a half inch out. F*ck. Did I jack the trigger press? Did I press an extra half-ounce on my cheek weld? Was my position in the bags a half-inch different when I re-built after coming out of recoil from the previous shot? Did my rifle pick up 7-degrees of cant that I didn't catch? Or any of the million other things that can screw up a shot.

Or was it the load, finally coughing up some honesty?

If Bryan's chart has one weakness, it's that it assumes perfect shooting. In the real world, of course, the farther we march to the right the more likely the numbers will blow up simply because of shooter error. Shooter fatigue is a very real thing and the longer the string the more likely we're going to see it color the question does this load shoot?

I didn't laugh when Jeff said he does development with 2-shot groups. Because in the beginning we're mostly trying to find out what doesn't work. And it doesn't require many shots to see that.

What's left, the small pool of candidates that remain, the ones that showed promise, will inevitably get loaded up again in subsequent rounds of testing. The statistics gods will, indeed, get their pound of flesh.

Just not today.

Got it.
Thanks!

 

[C.E.Smith043]

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.

I'm in a similar situation. My range is little over an 1hr. One way for me. I now load at the range.
For powder, I either pre-package mine or throw from my Redding powder thrower. And I seat using a small hand press. Sometimes i take brass that's already been primed, sometimes I prime at the bench with a hand primer.

 

[AckleymanII]

I believe that a 10 shot group is testing the wind, and a shooter's ability to catch the pick ups and let ups.

 

[MUP]

I'm loaded and going to the range tomorrow. LOTS of food for thought in this thread. Glad I'm on here to soak some of it in.

 

[Bill Norris]

I believe that a 10 shot group is testing the wind, and a shooter's ability to catch the pick ups and let ups.

AND the shooters ability to stay focused on the technique rather than freak out and think themselves out of good group. Seen it happen far too many times to not consider it a reality. And at that point if honesty prevails the shooter admits.

 

[Rule 243]

I'm in a similar situation. My range is little over an 1hr. One way for me. I now load at the range.
For powder, I either pre-package mine or throw from my Redding powder thrower. And I seat using a small hand press. Sometimes i take brass that's already been primed, sometimes I prime at the bench with a hand primer.

I considered doing what you're doing but decided against it.
Using stick powders I like to hand weigh every charge and I know all to well how the slightest air current can mess with a powder scale.
Plus I would have to get me a wagon to carry all my gear to the firing line and the firing line has no shade.

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

 

[C.E.Smith043]

I considered doing what you're doing but decided against it.
Using stick powders I like to hand weigh every charge and I know all to well how the slightest air current can mess with a powder scale.
Plus I would have to get me a wagon to carry all my gear to the firing line and the firing line has no shade.

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

I do sometimes pre-weight them